--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Symbian3/SDK/Source/GUID-E65D91AE-482F-5592-B83C-0F29126C2EFA.dita Thu Jan 21 18:18:20 2010 +0000
@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
+<!-- This component and the accompanying materials are made available under the terms of the License
+"Eclipse Public License v1.0" which accompanies this distribution,
+and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
+<!-- Initial Contributors:
+ Nokia Corporation - initial contribution.
+Contributors:
+-->
+<!DOCTYPE concept
+ PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept xml:lang="en" id="GUID-E65D91AE-482F-5592-B83C-0F29126C2EFA"><title>Using Signals to Handle Exceptions </title><prolog><metadata><keywords/></metadata></prolog><conbody><p>Signals provide an alternative method (to checking return values) of handling exceptions or failures. The following example code demonstrates how you can check the return value for a failure and also how you can register a handler for handling the failure asynchronously: </p> <codeblock id="GUID-49B4A39A-34F5-54D1-AD97-5AD50EFD9786" xml:space="preserve">#include <signal.h>
+#include <stdio.h>
+int func()
+ {
+ int success = 1;
+ // function logic
+ // success == 1 - Indicates that the function logic succeeded
+ // success == 0 - Indicates that the function logic failed
+ if(success)
+ return 0;
+ else
+ {
+ raise(SIGUSR1);
+ return -1;
+ }
+ }
+void sighandler(int signum)
+ {
+ if(signum == SIGUSR1)
+ // 'signal' method for checking failure
+ printf(“Error: An error occured in func().”);
+ else
+ printf(“Error: Unknown signal”);
+ }
+int main(void)
+ {
+ int retval = 0;
+ // When SIGUSR1 arrives, invoke sighandler()
+ signal(SIGUSR1,sighandler);
+ retval = func();
+ if(retval == -1)
+ // The return value method used for checking failure
+ printf("Error: An error occured in func().");
+ }</codeblock> </conbody><related-links><link href="GUID-66C1493D-5B85-558A-9A39-454E6EBA307B.dita"><linktext>Signal Emulation on Symbian
+ Platform</linktext> </link> <link href="GUID-186B9876-2A08-5F23-BB49-49EC34C51507.dita"><linktext>Using Signals to Terminate Processes</linktext> </link> <link href="GUID-6CF8A41B-C2DD-5D57-A71D-6405CE08A06B.dita"><linktext>Using Signals to Handle Asynchronous
+ Events</linktext> </link> </related-links></concept>
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