kernel/eka/drivers/usbcc/queue.cpp
changeset 0 a41df078684a
child 43 c1f20ce4abcf
equal deleted inserted replaced
-1:000000000000 0:a41df078684a
       
     1 // Copyright (c) 2002-2009 Nokia Corporation and/or its subsidiary(-ies).
       
     2 // All rights reserved.
       
     3 // This component and the accompanying materials are made available
       
     4 // under the terms of the License "Eclipse Public License v1.0"
       
     5 // which accompanies this distribution, and is available
       
     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
       
     7 //
       
     8 // Initial Contributors:
       
     9 // Nokia Corporation - initial contribution.
       
    10 //
       
    11 // Contributors:
       
    12 //
       
    13 // Description:
       
    14 // e32\drivers\usbcc\queue.cpp
       
    15 // Platform independent layer (PIL) of the USB Device controller driver:
       
    16 // Simple singly linked list + its iterator.
       
    17 // 
       
    18 //
       
    19 
       
    20 /**
       
    21  @file queue.cpp
       
    22  @internalTechnology
       
    23 */
       
    24 
       
    25 #include <drivers/usbc.h>
       
    26 
       
    27 
       
    28 void TSglQueLink::Enque(TSglQueLink* aLink)
       
    29 //
       
    30 // Enque this after aLink.
       
    31 //
       
    32 	{
       
    33 	iNext = aLink->iNext;
       
    34 	aLink->iNext = this;
       
    35 	}
       
    36 
       
    37 
       
    38 TSglQueBase::TSglQueBase(TInt aOffset)
       
    39 //
       
    40 // Constructor
       
    41 //
       
    42 	: iHead(NULL), iLast((TSglQueLink*) &iHead), iOffset(aOffset), iElements(0)
       
    43 	{
       
    44 	// ESQueOffsetNotAligned
       
    45 	__ASSERT_ALWAYS((iOffset % 4 == 0), Kern::Fault(KUsbPILPanicCat, __LINE__));
       
    46 	}
       
    47 
       
    48 
       
    49 void TSglQueBase::DoAddLast(TAny* aPtr)
       
    50 //
       
    51 // Add the object at the end of the queue.
       
    52 //
       
    53 	{
       
    54 	TSglQueLink* pL = PtrAdd((TSglQueLink*) aPtr, iOffset);
       
    55 	pL->Enque(iLast);
       
    56 	iLast = pL;
       
    57 	iElements++;
       
    58 	__ASSERT_DEBUG((iElements > 0), Kern::Fault(KUsbPILPanicCat, __LINE__));
       
    59 	}
       
    60 
       
    61 
       
    62 void TSglQueBase::DoRemove(TAny* aPtr)
       
    63 //
       
    64 // Remove the object from the queue.
       
    65 //
       
    66 	{
       
    67 	TSglQueLink* pP = (TSglQueLink*) (&iHead);
       
    68 	TSglQueLink* pL = PtrAdd((TSglQueLink*) aPtr, iOffset);
       
    69 	TSglQueLink* pN = pP->iNext;
       
    70 	while (pN)
       
    71 		{
       
    72 		if (pN == pL)
       
    73 			{
       
    74 			pP->iNext = pN->iNext;
       
    75 			if (iLast == pL)
       
    76 				{
       
    77 				iLast = pP;
       
    78 				if (iLast == NULL)
       
    79 					iLast = (TSglQueLink*) (&iHead);
       
    80 				}
       
    81 			iElements--;
       
    82 			__ASSERT_DEBUG((iElements >= 0), Kern::Fault(KUsbPILPanicCat, __LINE__));
       
    83 			return;
       
    84 			}
       
    85 		pP = pN;
       
    86 		pN = pP->iNext;
       
    87 		}
       
    88 	// This doesn't have to indicate an error (but might):
       
    89 	__KTRACE_OPT(KPANIC, Kern::Printf("TSglQueBase::DoRemove: ESQueLinkNotQueued"));
       
    90 	}
       
    91 
       
    92 
       
    93 TSglQueIterBase::TSglQueIterBase(TSglQueBase& aQue)
       
    94 //
       
    95 // Constructor.
       
    96 //
       
    97 	: iOffset(aQue.iOffset), iHead(aQue.iHead), iNext(aQue.iHead)
       
    98 	{
       
    99 	}
       
   100 
       
   101 
       
   102 void TSglQueIterBase::SetToFirst()
       
   103 //
       
   104 // Start from the beginning of the que.
       
   105 //
       
   106 	{
       
   107 	iNext = iHead->iNext;
       
   108 	}
       
   109 
       
   110 
       
   111 TAny* TSglQueIterBase::DoPostInc()
       
   112 //
       
   113 // Return the current pointer and increment.
       
   114 //
       
   115 	{
       
   116 	TAny* pN = iNext;
       
   117 	if (pN == NULL)
       
   118 		return NULL;
       
   119 	iNext = iNext->iNext;
       
   120 	return PtrSub(pN, iOffset);
       
   121 	}
       
   122 
       
   123 
       
   124 //---