/** @file | |
InterlockedCompareExchange64 function | |
Copyright (c) 2006 - 2008, Intel Corporation<BR> | |
All rights reserved. This program and the accompanying materials | |
are licensed and made available under the terms and conditions of the BSD License | |
which accompanies this distribution. The full text of the license may be found at | |
http://opensource.org/licenses/bsd-license.php | |
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
**/ | |
/** | |
Performs an atomic compare exchange operation on a 64-bit unsigned integer. | |
Performs an atomic compare exchange operation on the 64-bit unsigned integer specified | |
by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and | |
CompareValue is returned. If Value is not equal to CompareValue, then Value is returned. | |
The compare exchange operation must be performed using MP safe mechanisms. | |
@param Value A pointer to the 64-bit value for the compare exchange | |
operation. | |
@param CompareValue 64-bit value used in compare operation. | |
@param ExchangeValue 64-bit value used in exchange operation. | |
@return The original *Value before exchange. | |
**/ | |
UINT64 | |
EFIAPI | |
InternalSyncCompareExchange64 ( | |
IN UINT64 *Value, | |
IN UINT64 CompareValue, | |
IN UINT64 ExchangeValue | |
) | |
{ | |
_asm { | |
mov esi, Value | |
mov eax, dword ptr [CompareValue + 0] | |
mov edx, dword ptr [CompareValue + 4] | |
mov ebx, dword ptr [ExchangeValue + 0] | |
mov ecx, dword ptr [ExchangeValue + 4] | |
lock cmpxchg8b qword ptr [esi] | |
} | |
} |