kernel/eka/euser/cbase/ub_tque.cpp
changeset 0 a41df078684a
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-1:000000000000 0:a41df078684a
       
     1 // Copyright (c) 2004-2009 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\euser\cbase\ub_tque.cpp
       
    15 // 
       
    16 //
       
    17 
       
    18 #include <e32std.h>
       
    19 #include <e32std_private.h>
       
    20 
       
    21 
       
    22 
       
    23 
       
    24 // Class TTickCountQue
       
    25 /**
       
    26 @internalComponent
       
    27 @released
       
    28 
       
    29 Constructs an empty list header
       
    30 */
       
    31 TTickCountQue::TTickCountQue()
       
    32 	{}
       
    33 
       
    34 
       
    35 
       
    36 
       
    37 /**
       
    38 @internalComponent
       
    39 @released
       
    40 
       
    41 Adds the specified list element.
       
    42 
       
    43 The element is added into the list in order of its tick count.
       
    44 
       
    45 @param aRef The list element to be inserted.
       
    46 */
       
    47 void TTickCountQue::Add(TTickCountQueLink& aRef)
       
    48 	{
       
    49 	TTickCountQueLink* currentLink = (TTickCountQueLink*)(iHead.iNext);
       
    50 	TTickCountQueLink* addLink = &aRef;
       
    51 
       
    52 	while (	(currentLink != (TTickCountQueLink*)&iHead) &&
       
    53 			(((TInt)(addLink->iTickCount - currentLink->iTickCount)) >= 0)
       
    54 		)
       
    55 		{
       
    56 		currentLink = (TTickCountQueLink*)currentLink->iNext;
       
    57 		}
       
    58 
       
    59 	addLink->Enque(currentLink->iPrev);
       
    60 	}
       
    61 
       
    62 
       
    63 
       
    64 
       
    65 /**
       
    66 @internalComponent
       
    67 @released
       
    68 
       
    69 Removes the first list element from the linked list if its tick count
       
    70 is prior to the current tick count.
       
    71 
       
    72 @param aTickCount The current tick count.
       
    73 
       
    74 @return A pointer to the element removed from the linked list. This is NULL 
       
    75         if the first element has yet to expire or the queue is empty.
       
    76 */
       
    77 TTickCountQueLink* TTickCountQue::RemoveFirst(TUint aTickCount)
       
    78 	{
       
    79 	TTickCountQueLink* firstLink = (TTickCountQueLink*)iHead.iNext;
       
    80 
       
    81 	if (((TInt)(firstLink->iTickCount - aTickCount)) <= 0)
       
    82 		{
       
    83 		return RemoveFirst();
       
    84 		}
       
    85 	else
       
    86 		{
       
    87 		return NULL;
       
    88 		}
       
    89 	}
       
    90 
       
    91 
       
    92 /**
       
    93 @internalComponent
       
    94 @released
       
    95 
       
    96 Removes the first list element from the linked list, if any.
       
    97 
       
    98 @return A pointer to the element removed from the linked list. This is NULL, 
       
    99         if the queue is empty.
       
   100 */
       
   101 TTickCountQueLink* TTickCountQue::RemoveFirst()
       
   102 	{
       
   103 	TTickCountQueLink* firstLink = (TTickCountQueLink*)iHead.iNext;
       
   104 
       
   105 	if (firstLink != (TTickCountQueLink*)&iHead)
       
   106 		{
       
   107 		firstLink->Deque();
       
   108 		return firstLink;
       
   109 		}
       
   110 
       
   111 	return NULL;
       
   112 	}
       
   113 
       
   114 
       
   115 
       
   116 
       
   117 /**
       
   118 @internalComponent
       
   119 @released
       
   120 
       
   121 Gets a pointer to the first list element in the doubly linked list.
       
   122 
       
   123 @return A pointer to the first list element in the doubly linked list. If 
       
   124         the list is empty, this pointer is not necessarily NULL and must not
       
   125 		be assumed to point to a valid object.
       
   126 */
       
   127 TTickCountQueLink* TTickCountQue::First() const
       
   128 	{
       
   129 #if defined (_DEBUG)
       
   130 	__DbgTestEmpty();
       
   131 #endif
       
   132     return((TTickCountQueLink*)iHead.iNext);
       
   133     }