author | Dominic Pinkman <dominic.pinkman@nokia.com> |
Fri, 16 Jul 2010 17:23:46 +0100 | |
changeset 12 | 80ef3a206772 |
parent 9 | 59758314f811 |
permissions | -rw-r--r-- |
9
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<?xml version="1.0" encoding="utf-8"?> |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<!-- This component and the accompanying materials are made available under the terms of the License |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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"Eclipse Public License v1.0" which accompanies this distribution, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<!-- Initial Contributors: |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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Nokia Corporation - initial contribution. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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Contributors: |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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--> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<!DOCTYPE concept |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<concept id="GUID-314FAEB5-946C-4090-B6AA-1BEEC9BE8EFB" xml:lang="en"><title>Common |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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Error Patterns - Case Studies</title><shortdesc>Describes a few common error patterns that were found while testing |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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code designed for use in an SMP environment.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<p>During development and testing, a number of areas of code have been identified |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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that demonstrate some of the SMP common error patterns. These case studies |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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are described below to illustrate how these errors can be identified and typical |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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code fixes.</p> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<section id="C"><title>Relying on linear execution</title><p>The ETEL client |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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API makes use of an unusual implementation class called <codeph>CPtrHolder</codeph>. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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Each ETEL client sub-session (derived from <codeph>RTelSubSessionBase</codeph>) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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owns a <codeph>CPtrHolder</codeph>. This class stores a dynamic array of descriptors, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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each of which corresponds to the IPC data used for a specific subset of ETEL |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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client/server messages. This allows the server to read/write data from/to |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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valid client descriptors when there are multiple outstanding messages from |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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a particular client sub-session. </p> <p>A problem occurred when the same |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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client sub-session sent two asynchronous messages of the same type (therefore |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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using the same <codeph>CPtrHolder</codeph> descriptor) to the ETEL server |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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in a short space of time. The problem did not manifest itself in a single |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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core environment because the ETEL server always ran at a higher priority than |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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the ETEL client, and so the first message was always completed before the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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client sent the second message. However, in an SMP environment, the server |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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runs on a different CPU to the client and had not started processing the first |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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message by the time the client sent the second message. The <codeph>CPtrHolder</codeph> descriptor |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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was updated with data from the second message but the server was still expecting |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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to read data from the first message. As a result, the first message was completed |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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by the server with a <codeph>KErrCorrupt</codeph> error code. </p> <p>The |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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solution was to identify which messages could suffer from this problem and |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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send a synchronous <codeph>EEtelFlushInterfaceQueue</codeph> message to the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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server immediately after the asynchronous request. This guaranteed that the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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server would have read the data from the first asynchronous message by the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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time the second asynchronous message was sent. </p></section> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<section id="D"><title>Relying on thread suspension when making asynchronous |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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calls</title><p>In a way, the "Non-synchronized IPC calls" category is a subset |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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of this category. Whenever code makes assumptions about which order threads |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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are executed based on thread priority, there is a potential problem. In most |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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cases, it is best to think of thread priority as nothing more than a hint |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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to the scheduler. In an environment where multiple processors are being activated |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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and deactivated dynamically it is not safe to make any assumptions concerning |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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which threads will run at a given time. </p><p>Consider the case below where |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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a mutex is acquired by two threads with different priorities: </p><codeblock xml:space="preserve">// High priority thread (T1) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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iMutex.Wait(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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DoFirstThing(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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iMutex.Signal(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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|
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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// Low priority thread (T2) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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iMutex.Wait(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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DoSecondThing(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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iMutex.Signal();</codeblock><p>Even on a single processor system it is unwise |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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to assume that T1 would acquire the lock before T2. For example, T1 could |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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be suspended because of a page fault. While it is suspended, the scheduler |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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could run T2, causing it to acquire the lock and execute <codeph>DoSecondThing()</codeph>, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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which is not the desired behaviour. In an SMP context both threads could be |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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running concurrently, making it even harder to predict which thread will acquire |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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the lock first. While a mutex may be used to prevent concurrent access to |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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a shared resource, it cannot be used to force two threads to perform actions |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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in a certain sequence. The solution is to use an <xref href="GUID-AED27A76-3645-3A04-B80D-10473D9C5A27.dita"><apiname>RSemaphore</apiname></xref> initialised |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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with a value of 0, allowing one thread to suspend until another thread signals |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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that it is safe to proceed. We would use this in the above example as follows: </p><codeblock xml:space="preserve">// T1 |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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DoFirstThing(); |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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iSemaphore.Signal(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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|
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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// T2 |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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iSemaphore.Wait(); |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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DoSecondThing(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</codeblock><p>Now, T2 waits for explicit notification from T1. We are completely |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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agnostic about the relative thread priorities. Should T2 execute first, the |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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semaphore would be decremented and the thread blocked before executing <codeph>DoSecondThing()</codeph>. |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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It can only proceed once T1 has executed <codeph>DoFirstThing()</codeph> and |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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signalled the semaphore. </p><p><b>Case study: Thread <codeph>EwSrv.exe</codeph> panics |
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with <codeph>E32USER-CBase 46</codeph> on H4. </b></p><p>This is another case |
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of a bad assumption about thread priorities but with a different result. The |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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problem manifested itself on an SMP environment when pressing keys a lot within |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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an edit window. The edit window cursor is an animation that periodically generates |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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redraw events within the window server. The scheduling of these redraw events |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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86 |
was altered by the events generated by the key presses, which led to a stray |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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87 |
event panic (<codeph>E32USER-CBase 46</codeph>) in the window server main |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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88 |
thread. As this is a critical thread, the kernel then faulted. Like many stray |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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89 |
event panics, this problem was difficult to diagnose but easy to fix. </p><p>The |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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90 |
window server has a mechanism for redrawing animations involving a separate |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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91 |
low-priority thread (called the kickback thread) encapsulated within an active |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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92 |
object that controls that thread, called <codeph>CKickBack</codeph>. Kickbacks |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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93 |
from the window server main thread are executed through this function: </p><codeblock xml:space="preserve">void CWindowServer::CDefaultAnimationScheduler::CKickBack::RequestKickBack() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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94 |
{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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95 |
if (!IsActive()) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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96 |
{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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97 |
TRequestStatus * status = &idleStatus; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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98 |
iIdleThread.RequestComplete(status, KErrNone); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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99 |
iStatus = KRequestPending; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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100 |
SetActive(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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101 |
} |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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102 |
} |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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103 |
</codeblock><p>The kickback thread is signalled using a handle to that thread |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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104 |
(<codeph>iIdleThread</codeph>) and the <codeph>iIdleStatus</codeph> semaphore. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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105 |
The <codeph>CKickBack</codeph> active object is then set active and waits |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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106 |
for the kickback thread to signal back to the main thread using the <codeph>iStatus</codeph> semaphore. </p><p>After |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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107 |
construction, the kickback thread spends its whole time in an endless loop, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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108 |
waiting for <codeph>iIdleStatus</codeph> to be signalled from the window server |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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109 |
main thread: </p><codeblock xml:space="preserve">void CWindowServer::CDefaultAnimationScheduler::CKickBack::Loop() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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110 |
{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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111 |
FOREVER |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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112 |
{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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113 |
User::WaitForRequest(iIdleStatus); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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114 |
TRequestStatus * status = &iStatus; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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115 |
iWservThread.RequestComplete(status,KErrNone); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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116 |
} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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117 |
} |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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118 |
</codeblock><p>Once <codeph>iIdleStatus</codeph> is completed, the kickback |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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119 |
thread resumes execution, immediately signals completion of the <codeph>iStatus</codeph> semaphore |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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120 |
back to the window server main thread (via the <codeph>iWservThread RThread</codeph> handle), |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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121 |
then waits for the next kickback. </p><p>Back in the window server thread, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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122 |
the <codeph>CKickBack</codeph> active object is run, which simply calls back |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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123 |
a function that was supplied at construction time: </p><codeblock xml:space="preserve">void CWindowServer::CDefaultAnimationScheduler::CKickBack::RunL() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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124 |
{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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125 |
iCallBack.CallBack(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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126 |
} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</codeblock><p>The time between the initial <codeph>RequestKickBack()</codeph> and <codeph>CKickBack::RunL()</codeph> should |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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128 |
be very short but there is an opportunity for higher priority threads (or |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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129 |
active objects in the window server) to get some CPU time in-between. </p><p>The |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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130 |
problem occurs after the call to <codeph>RequestComplete()</codeph> in <codeph>RequestKickBack()</codeph>. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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131 |
On a single core environment, the subsequent assignment <codeph>iStatus=KRequestPending</codeph> will |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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always happen before the kickback thread can resume execution (because the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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133 |
main thread has a higher priority than the kickback thread). On an SMP environment |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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134 |
however, the kickback thread can resume execution in parallel with the main |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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135 |
thread, on a different CPU. It's possible for the<codeph> RequestComplete()</codeph> on <codeph>iStatus</codeph> in |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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136 |
the <codeph>Loop()</codeph> function of the kickback thread to occur before |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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the<codeph> iStatus=KRequestPending </codeph>assigment in the main thread. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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138 |
If this happens then the <codeph>KErrNone</codeph> value of <codeph>iStatus</codeph> will |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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139 |
be overwritten by <codeph>KRequestPending</codeph>, and the <codeph>CKickBack</codeph> active |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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140 |
object will end up being active but with an <codeph>iStatus</codeph> of <codeph>KRequestPending</codeph>. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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141 |
The active scheduler will then receive the signal from the kickback thread |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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142 |
and iterate through its active objects, looking for the one that is active |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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143 |
but not pending. It will get to the end of the list without finding a valid |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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144 |
active object, causing a stray event panic. </p><p>The simple solution is |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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145 |
to bring forward the assignment of <codeph>iStatus</codeph> in <codeph>RequestKickBack()</codeph> to |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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146 |
before the call to <codeph>RequestComplete()</codeph>. </p><codeblock xml:space="preserve">void CWindowServer::CDefaultAnimationScheduler::CKickBack::RequestKickBack() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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147 |
{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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148 |
if (!IsActive()) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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149 |
{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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150 |
iStatus = KRequestPending; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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151 |
SetActive(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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152 |
TRequestStatus * status = &idleStatus; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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153 |
iIdleThread.RequestComplete(status, KErrNone); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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154 |
} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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155 |
} |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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156 |
</codeblock><p>Stray event panics can be particularly difficult to track down |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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157 |
because the call stack at the point it panics does not show the root cause |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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158 |
of the problem. </p></section> |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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159 |
<section id="GUID-A959F5DF-74C9-4F7B-B549-A971684E056E"><title>Unsafe assumption |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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160 |
of Publish and Subscribe message ordering</title><p>The Publish and Subscribe |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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mechanism is one of the standard IPC mechanisms available in Symbian platform. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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162 |
There are unique SMP error patterns associated with its use. </p><p><b>Case |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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163 |
study: <codeph>t_InitialiseLocale</codeph> fails on X86 SMP Hardware </b></p><p>The |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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164 |
Generic OS Services utility, <filepath>initialiselocale.exe</filepath> uses |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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165 |
a Publish and Subscribe property to indicate to subscribers that locale initialisation |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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is complete. It also uses the Rendezvous mechanism to synchronise with threads |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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167 |
that are waiting for <filepath>initialiselocale.exe</filepath> to start. The |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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168 |
problem manifested itself in the test program <filepath>t_initialiselocale.exe</filepath>, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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169 |
which first rendezvous with <filepath>initialiseLocale.exe</filepath> and |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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170 |
then checks whether it has initialised using the P&S property. Here are |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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the respective code fragments: </p><p>From <filepath>os/ossrv/lowlevellibsandfws/apputils/initlocale/src/initialiselocale.cpp</filepath>:</p><codeblock xml:space="preserve">void CExtendedLocaleManager::ConstructL() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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{ |
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TUid LocalePropertyUid; |
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LocalePropertyUid.iUid = KUidLocalePersistProperties ; |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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175 |
... |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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//now call RProcess::Rendezvous to indicate initialiseLocale is completed with no error |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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RProcess().Rendezvous(KErrNone); |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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178 |
|
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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// Set property to indicate initialisation complete |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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User::LeaveIfError(RProperty::Set(LocalePropertyUid, EInitialisationState, ELocaleInitialisationComplete)); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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181 |
|
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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// All ready to go! Start the active sheduler. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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CActiveScheduler::Start(); |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</codeblock><p>From <filepath>os/ossrv/lowlevellibsandfws/apputils/initlocale/test/t_initialiselocale.cpp</filepath>:</p><codeblock xml:space="preserve">void TestLocaleChanges() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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RProcess process; |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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188 |
... |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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TInt r = process.Create(KInitialiseLocaleExeName, KNullDesC); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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if(r == KErrNone) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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TRequestStatus stat; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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process.Rendezvous(stat); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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process.Resume(); // Start the process going |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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//wait for the locale initialisation to complete first before testing |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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User::WaitForRequest(stat); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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TEST2((stat.Int()==KErrNone)||(stat.Int()==KErrAlreadyExists),ETrue); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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TInt flag; |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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TUid initLocaleUid=TUid::Uid(KUidLocalePersistProperties); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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r=RProperty::Get(initLocaleUid,(TUint)EInitialisationState,flag); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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TEST2(r,KErrNone); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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//check for the P&S flag that indicates localeinitialisation complete |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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TEST2(flag,ELocaleInitialisationComplete); //!!! Test failed !!! |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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... |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</codeblock><p>The problem manifested itself in an SMP environment because |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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the <codeph>t_initialiselocale</codeph> main thread reached the test marked |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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"Test failed" before the setting of this property in the <codeph>InitialiseLocale</codeph> main |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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thread was published. Therefore, the test failed. The solution was to simply |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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move the setting of the <codeph>KUidLocalePersistProperties</codeph> property |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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in <codeph>InitialiseLocale</codeph> to before the call to <codeph>Rendezvous()</codeph>. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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It could then be guaranteed that the property would be published by the time <codeph>t_initialiselocale</codeph> had |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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rendezvoused with <codeph>InitialiseLocale</codeph>. </p><codeblock xml:space="preserve">void CExtendedLocaleManager::ConstructL() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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TUid LocalePropertyUid; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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LocalePropertyUid.iUid = KUidLocalePersistProperties ; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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216 |
... |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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// Set property to indicate initialisation complete |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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User::LeaveIfError(RProperty::Set(LocalePropertyUid, EInitialisationState, ELocaleInitialisationComplete)); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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//now call RProcess::Rendezvous to indicate initialiseLocale is completed with no error |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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RProcess().Rendezvous(KErrNone); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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// All ready to go! Start the active sheduler. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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CActiveScheduler::Start(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</codeblock></section> |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<section id="E"><title>Relying on thread priority for execution order</title><p><b>Case |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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study: Priority dependence in the file server in <codeph>T_CFSSIMPLE</codeph> </b></p><p>The |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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file server has a main thread, a thread for each drive and a disconnect thread |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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(plus some other ones not relevant to this discussion). All requests are received |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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by the main thread and each drive has a lock associated with it. </p><p>When |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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an <codeph>RFs</codeph> session is closed, the main thread passes the request |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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to the disconnect thread, and the disconnect thread eventually ends up running <codeph>TFsSessionDisconnect::DoRequestL()</codeph>. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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Closing the session is asynchronous within the file server even though it |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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appears to be synchronous to the client. There may be outstanding requests |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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on any number of drives so every drive thread needs to be told to cancel any |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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pending requests before the session can be entirely deleted by the file server. </p><p>Before |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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the fix,<codeph> TFsSessionDisconnect::DoRequestL</codeph>() looped over the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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drive array and did the following for each drive: </p><ol> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="F"><p>Lock the drive.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="G"><p>Check whether the drive exists.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="H"><p>If it does exist, send a request to the drive thread to clean |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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up any pending requests that are were going to be handled for the session |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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being closed.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="I"><p>Unlock the drive.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="J"><p>Wait for the cleanup request to complete. </p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="K"><p>Check whether write caching is enabled on that drive.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="L"><p>If it is enabled, send a request to the drive thread to flush |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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any dirty data.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="M"><p>Wait for the flush request to complete.</p></li> |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</ol><p>The problem occurred when the <codeph>T_CFSSIMPLE</codeph> test application |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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(after performing its tests) unmounted a drive just before closing its <codeph>RFs</codeph> session. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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Unmounting a drive is also asynchronous from the file server's perspective |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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- the main thread has to send a request to the drive thread so that it shuts |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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itself down cleanly. While unmounting a drive, the drive is locked. </p><p>The |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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disconnect thread is normally the highest priority thread in the file server, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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even higher than the main thread, so usually nothing else gets to issue any |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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new requests while this is happening. However, in an SMP environment (or when |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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the crazy scheduler is being used), it's possible for an unmount request to |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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happen at the same time as a session disconnect. </p><p>If one of the drives |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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is unmounted at the same time as the session disconnect, then the unmount |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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sets the drive as not present and kills the associated thread. Step 3 above |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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261 |
is safe because it acquires the lock on the drive before modifying it. The |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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disconnect thread may get there first and send the cleanup request; then the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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drive thread unmounts itself (since the lock is released) and the cleanup |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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request completes with <codeph>KErrNotReady</codeph> (which is ignored by |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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the code). Alternatively, the unmount request may get there first; then the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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disconnect thread never thinks the drive is there in the first place so does |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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not issue the cleanup request. </p><p>The problem was in step 7 - this part |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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of the code didn't lock the drive or check whether it existed. It assumed |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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that because the drive existed earlier in the loop it still continued to exist. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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Since step 4 unlocked the drive, this was not necessarily true - there was |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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an opportunity for it to be unmounted and a flush request sent to a non-existent |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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drive, resulting in a panic. </p><p>The solution was to protect step 7 with |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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a lock and a "check whether drive exists" operation like in step 3. Here is |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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the actual code change: </p><p>Before: </p><p>From <filepath>os/kernelhwsrv/userlibandfileserver/fileserver/sfile/sf_ses.cpp</filepath></p><codeblock xml:space="preserve">if (TFileCacheSettings::Flags(i) & (EFileCacheWriteEnabled | EFileCacheWriteOn)) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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275 |
{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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// Flush dirty data pR->Set(FlushDirtyDataOp,aRequest->Session()); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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pR->SetDriveNumber(i); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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pR->Status()=KRequestPending; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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pR->Dispatch(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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User::WaitForRequest(pR->Status()); // check request completed or cancelled (by file system dismount) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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__ASSERT_ALWAYS(pR->Status().Int()==KErrNone||pR->Status().Int()==KErrCancel,Fault(ESessionDisconnectThread2)); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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__THRD_PRINT2(_L("Flush dirty data on drive %d r=%d"),i,pR->Status().Int()); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</codeblock><p>After: </p><codeblock xml:space="preserve">if (TFileCacheSettings::Flags(i) & (EFileCacheWriteEnabled | EFileCacheWriteOn)) |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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FsThreadManager::LockDrive(i); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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if(!FsThreadManager::IsDriveAvailable(i,EFalse)||FsThreadManager::IsDriveSync(i,EFalse)) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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FsThreadManager::UnlockDrive(i); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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continue; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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// Flush dirty data |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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pR->Set(FlushDirtyDataOp,aRequest->Session()); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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pR->SetDriveNumber(i); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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pR->Status()=KRequestPending; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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pR->Dispatch(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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FsThreadManager::UnlockDrive(i); |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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User::WaitForRequest(pR->Status()); |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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// check request completed or cancelled (by file system dismount which completes requests with KErrNotReady) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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__ASSERT_ALWAYS(pR->Status().Int()==KErrNone||pR->Status().Int()==KErrNotReady,Fault(ESessionDisconnectThread2)); |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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__THRD_PRINT2(_L("Flush dirty data on drive %d r=%d"),i,pR->Status().Int()); |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</codeblock><p><b>Case study: Unexpected running of low priority active object</b> </p><p>There |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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is a common pattern used in test code (and possibly also production code) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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where: </p><ol> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="N"><p>A low priority active object is used and immediately set "ready |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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to run". (Typically <xref href="GUID-619AF4A9-4DAF-3FA4-A704-717DB30B5389.dita"><apiname>CAsyncOneShot</apiname></xref> is used for the active |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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object.)</p></li> |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="O"><p>The active scheduler is nested.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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<li id="P"><p>One or more high priority active objects are started (probably |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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several times), which all make requests on a server. </p></li> |
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80ef3a206772
Week 28 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 1897, Bug 344, Bug 2681, Bug 463, Bug 1522.
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<li id="Q-GENID-1-11-1-1-7-1-6-1-3-5-19-4"><p>The high priority active object(s) are serviced and immediately |
9
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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restarted. This continues until there is no more work for the high priority |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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active object(s) to do.</p></li> |
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Week 28 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 1897, Bug 344, Bug 2681, Bug 463, Bug 1522.
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<li id="Q-GENID-1-11-1-1-7-1-6-1-3-5-19-5"><p>The low priority active object runs and un-nests the active |
9
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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scheduler.</p></li> |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</ol><p>In a single core environment, the server always processes the client |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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requests before the client can run any other code (because the server runs |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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in a higher priority thread). When the client thread runs, the high priority |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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active objects are already "ready to run" and get serviced before the low |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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priority active object. </p><p>This pattern breaks under SMP conditions because |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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the client thread can continue to run on a different CPU at the same time |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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that the server is processing the client requests. At this point, the only |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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active object in the client thread that is "ready to run" is the low priority |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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active object. This object gets serviced and the active scheduler is stopped |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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earlier than expected. </p><p>For example, the window server test code function <codeph>WaitForRedrawsToFinish()</codeph> suffered |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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from the problem described above: </p><codeblock xml:space="preserve">EXPORT_C void WaitForRedrawsToFinish() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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{ |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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CStopTheScheduler* ps=new CStopTheScheduler(ETlibRedrawActivePriority-1); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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if(ps) |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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333 |
{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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ps->Call(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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CActiveScheduler::Start(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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delete ps; |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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} |
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Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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</codeblock><p>This creates a low priority active object and then nests the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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active scheduler. The low priority active object used was defined like this: </p><codeblock xml:space="preserve">class CStopTheScheduler : public CAsyncOneShot |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
342 |
public: |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
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343 |
CStopTheScheduler(TInt aPriority); //Pure virtual function from CActive void RunL(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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344 |
}; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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345 |
|
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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346 |
CStopTheScheduler::CStopTheScheduler(TInt aPriority) : CAsyncOneShot(aPriority) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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347 |
{} |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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348 |
|
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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349 |
void CStopTheScheduler::RunL() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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350 |
{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
351 |
CActiveScheduler::Stop(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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352 |
} |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
353 |
</codeblock><p>This just un-nests the active scheduler when it runs. Before <codeph>WaitForRedrawsToFinish()</codeph> is |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
354 |
called, there is already an outstanding request on the window server for it |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
355 |
to notify the test thread that there is a redraw event ready. If there is |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
356 |
a redraw ready, then a high priority active object called <codeph>CTRedraw</codeph> is |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
357 |
serviced, which processes the redraw event and immediately requests notification |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
358 |
of the next redraw from the server. </p><codeblock xml:space="preserve">EXPORT_C void CTRedraw::RunL() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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359 |
{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
360 |
TWsRedrawEvent redraw; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
361 |
iWs->GetRedraw(redraw); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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changeset
|
362 |
if (redraw.Handle()!=0 && redraw.Handle()!=ENullWsHandle) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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363 |
((CTWin*)redraw.Handle())->Redraw(redraw.Rect()); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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364 |
iWs->RedrawReady(&iStatus); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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365 |
SetActive(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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366 |
} |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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367 |
</codeblock><p>This is a simplified version of the code.</p><p>The intention |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
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368 |
was that <codeph>CTRedraw::RunL()</codeph> would run many times, as long as |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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369 |
there were outstanding redraw events, before <codeph>CStopTheScheduler::RunL()</codeph> was |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
370 |
able to run. When there were no more outstanding events, <codeph>CStopTheScheduler::RunL()</codeph>would |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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371 |
run, which then allowed the code after <codeph>WaitForRedrawsToFinish()</codeph> to |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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372 |
run. </p><p>In an SMP environment though, every time <xref href="GUID-62F4FF8B-5E02-3312-8DB8-F8B2D2E7FC47.dita"><apiname>WaitForRedrawsToFinish()</apiname></xref> was |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
373 |
called, only one window was redrawn, even though redraw events for several |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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changeset
|
374 |
windows were waiting. <xref href="GUID-869360A0-8C14-3AB3-8FC8-94E12E7F21D7.dita#GUID-869360A0-8C14-3AB3-8FC8-94E12E7F21D7/GUID-7F533463-F972-3B53-9AAD-061EF10DCD20"><apiname>CTRedraw::RunL()</apiname></xref> only ran once before <xref href="GUID-B394E21C-942B-3A5D-AA57-1CE892826911.dita#GUID-B394E21C-942B-3A5D-AA57-1CE892826911/GUID-53EA2F9F-9730-3A8A-B206-96D1223D2FA6"><apiname>CStopTheScheduler::RunL()</apiname></xref> managed |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
375 |
to run. </p><p>There are at least two ways to fix this problem: </p><ol> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
376 |
<li id="S"><p>After the call to <xref href="GUID-E3F0CB70-58E4-32FD-9828-71DF2F9976D3.dita"><apiname>RedrawReady()</apiname></xref>, add another |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
377 |
synchronous call to the window server. This solution is undesirable as the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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diff
changeset
|
378 |
additional IPC compromises the speed of the test code.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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diff
changeset
|
379 |
<li id="T"><p>Modify the class <codeph>CStopTheScheduler</codeph> so that |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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changeset
|
380 |
in its<codeph> RunL()</codeph> it does: </p><codeblock xml:space="preserve">void CStopTheScheduler::RunL() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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381 |
{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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diff
changeset
|
382 |
//Here a synchronous call to WSERV is made to make sure the asynchronous call has finished being processed |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
383 |
if (iClient->RedrawHandler()->iStatus==KRequestPending) //Check to see if the redraw active object is now ready to run |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
384 |
CActiveScheduler::Stop(); //If it is not ready to run un-nest the active scheduler |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
385 |
else |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
386 |
Call(); //If it is ready to run set this active object ready to run again |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
387 |
} |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
388 |
</codeblock><p>This was the solution that was chosen. </p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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changeset
|
389 |
</ol></section> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
390 |
<section id="W"><title>Premature recreation of named objects</title><p>This |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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changeset
|
391 |
category of problems relates to the asynchronous cleanup of objects owned |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
392 |
by the kernel. On the user-side this involves classes derived from <codeph>RHandleBase</codeph>, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
393 |
corresponding to a <codeph>DObject</codeph> in the kernel. These problems |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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diff
changeset
|
394 |
take the following form: </p><ul> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
395 |
<li><p>1a. An <codeph>RHandleBase</codeph> derived object is created user-side.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
396 |
<li><p>1b. A corresponding <codeph>DObject</codeph> is created kernel-side.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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changeset
|
397 |
<li><p>2. Something is done with that object.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
398 |
<li><p>3a. All user-side handles to that object are destroyed.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
399 |
<li><p>3b. Deletion of the corresponding <codeph>DObject</codeph> is initiated.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
400 |
<li><p>4a. A second <codeph>RHandleBase</codeph> derived object with the same |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
401 |
name is created user-side.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
402 |
<li><p>4b. A second corresponding <codeph>DObject</codeph> with the same name |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
403 |
is created kernel-side.</p></li> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
404 |
</ul><p>The problem is that all <codeph>DObject</codeph> names must be unique |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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changeset
|
405 |
and 3b is not guaranteed to complete before 4b starts, therefore 4b (and 4a) <i>may</i> fail |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
406 |
with <codeph>KErrAlreadyExists</codeph>. </p><p>This most commonly manifests |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
407 |
itself during thread cleanup and so this case warrants more detailed discussion. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
408 |
When a thread either exits or is killed externally, the thread itself runs |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
409 |
an exit handler inside the kernel. This runs at a slightly higher priority |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
410 |
than normal application threads and does part of the cleanup, including completing |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
411 |
log-ons. The last thing the exit handler does is to queue a DFC which gets |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
412 |
executed by the supervisor thread inside the kernel. This completes the cleanup, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
413 |
including freeing the thread stacks and closing the <codeph>DThread</codeph> object |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
414 |
itself. If no other threads or processes have open handles on the <codeph>DThread</codeph>, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
415 |
it is completely deleted at this point. </p><p>On a single processor system, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
416 |
the following code would always work provided that the thread running it has |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
417 |
a lower priority than the supervisor thread and there are no undertakers in |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
418 |
the system (which is true for a lot of test code): </p><codeblock xml:space="preserve">RThread t; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
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|
419 |
TInt r = t.Create(KName, ...); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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|
420 |
assert(r==KErrNone); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
421 |
TRequestStatus s; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
422 |
t.Logon(s); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
423 |
assert(s.Int()==KRequestPending); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
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changeset
|
424 |
t.Resume(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
425 |
User::WaitForRequest(s); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
426 |
// read exit information for thread and do something with it |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
427 |
t.Close(); // thread actually disappears here |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
428 |
r = t.Create(KName,...); // recreate with same name |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
429 |
assert(r==KErrNone); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
430 |
</codeblock><p>The exit handler and supervisor would both run ahead of the |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
431 |
calling thread, so by the time the <codeph>t.Close()</codeph> line is executed |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
432 |
there would only be one handle remaining on the <codeph>DThread</codeph>. |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
433 |
If there are undertakers in the system, the supervisor thread exit handler |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
434 |
would open a handle on the exiting thread for each undertaker. The thread |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
435 |
would not then go away until all those handles were closed and the code above |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
436 |
would potentially fail. </p><p>On an SMP system the code above would clearly |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
437 |
fail, since regardless of thread priorities or undertakers, the supervisor |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
438 |
thread could run on a separate CPU from the thread calling <codeph>Close()</codeph> and |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
439 |
there is no guarantee that on return from <codeph>Close()</codeph> the thread |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
440 |
would have been destroyed. </p><p>A similar issue exists where, instead of |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
441 |
recreating the thread with the same name, a kernel heap check is performed |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
442 |
to ensure all kernel memory has been cleaned up. </p><p>There are three possibilities |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
443 |
to fix this problem: </p><ol> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
444 |
<li id="X"><p>Recreate the thread with a different name.</p></li> |
12
80ef3a206772
Week 28 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 1897, Bug 344, Bug 2681, Bug 463, Bug 1522.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
9
diff
changeset
|
445 |
<li id="Y-GENID-1-11-1-1-7-1-6-1-3-6-12-2"><p>Wait a "little bit" before recreating the thread (or performing |
9
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
446 |
the heap check). </p><p>This is almost always a bad idea as there is no way |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
447 |
of knowing how long to wait and this may be different on any future system.</p></li> |
12
80ef3a206772
Week 28 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 1897, Bug 344, Bug 2681, Bug 463, Bug 1522.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
9
diff
changeset
|
448 |
<li id="Y-GENID-1-11-1-1-7-1-6-1-3-6-12-3"><p>Wait for the object concerned to be completely destroyed.</p></li> |
9
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
449 |
</ol><p>In general, option 1 is preferred. For code that is likely to encounter |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
450 |
the problem in practice, APIs should be provided to aid with creating objects |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
451 |
with a unique name. For example, the <codeph>TDynamicDfcQue</codeph> and <codeph>Kern::DynamicDfcQCreate</codeph> APIs |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
452 |
are provided to help with creating DFC threads with unique names. </p><p>Using |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
453 |
a different name is easy in the above code example but it's not possible when |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
454 |
checking for kernel memory leaks (as in a lot of test code). In this case, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
455 |
solution 3 can be employed, with the aid of <codeph>RHandleBase::NotifyDestruction </codeph>(in <filepath>e32cmn.h</filepath>) |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
456 |
and <codeph>CLOSE_AND_WAIT</codeph> (in <filepath>e32test.h</filepath>). This |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
457 |
solution is acceptable in a closed system, where there is control over all |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
458 |
handles to the object being recreated but in general there is no way of knowing |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
459 |
whether some component has an open handle to a thread (or what component it |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
460 |
might be). Any component can open a thread by name and hold the handle forever, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
461 |
jamming the system while it waits for the handle to be closed. Therefore, |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
462 |
in practice you should always attempt to recreate it with a different name |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
463 |
(option 1). </p><p><b>Case study: <codeph>t_NamedPlugins</codeph> fails on |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
464 |
X86 SMP Hardware</b> </p><p>This is a classic example of the thread recreation |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
465 |
problem, with solution 3 employed as the fix.</p><p>From <filepath>os/ossrv/lowlevellibsandfws/apputils/tsrc/t_namedplugins.cpp</filepath>:</p><codeblock xml:space="preserve">LOCAL_C void NamedPluginsPanicConditionsThread() |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
466 |
{ |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
467 |
... |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
468 |
_LIT(KName, "NamedPlugins_Panic_Thread"); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
469 |
RThread thread; |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
470 |
... |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
471 |
// Test EBafPanicBadResourceFileFormat |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
472 |
TInt rc = thread.Create(KName,...); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
473 |
TEST(rc==KErrNone); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
474 |
... |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
475 |
thread.Close(); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
476 |
// Test EBafPanicBadArrayPosition |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
477 |
rc = thread.Create(KName,...); |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
478 |
TEST(rc==KErrNone); //!!! Test failed !!! |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
479 |
... |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
480 |
</codeblock><p>The simple solution was to change the <codeph>thread.Close()</codeph> call |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
481 |
to <codeph>CLOSE_AND_WAIT(thread)</codeph> instead. This is acceptable for |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
482 |
test code because it is known that there will be no other threads holding |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
483 |
on to a handle to the <codeph>NamedPlugins</codeph> thread. </p></section> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
484 |
</conbody><related-links> |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
485 |
<link href="GUID-E55F9286-F586-4665-93D8-86F1E7BE2C7C.dita"><linktext>SMP Developer |
59758314f811
Week 23 contribution of PDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents:
5
diff
changeset
|
486 |
Tips</linktext></link> |
5
f345bda72bc4
Week 12 contribution of PDK documentation_content. See release notes for details. Fixes Bug 2054, Bug 1583, Bug 381, Bug 390, Bug 463, Bug 1897, Bug 344, Bug 1319, Bug 394, Bug 1520, Bug 1522, Bug 1892"
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
3
diff
changeset
|
487 |
</related-links></concept> |