MdePkg/Library/BaseSynchronizationLib/X64/InterlockedCompareExchange64.c

   1 /** @file
   2   InterlockedCompareExchange64 function
   3
   4   Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 /**
  10   Microsoft Visual Studio 7.1 Function Prototypes for I/O Intrinsics.
  11 **/
  12
  13 __int64
  14 _InterlockedCompareExchange64 (
  15   __int64 volatile  *Destination,
  16   __int64           Exchange,
  17   __int64           Comperand
  18   );
  19
  20 #pragma intrinsic(_InterlockedCompareExchange64)
  21
  22 /**
  23   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
  24
  25   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
  26   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
  27   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
  28   The compare exchange operation must be performed using MP safe mechanisms.
  29
  30   @param  Value         A pointer to the 64-bit value for the compare exchange
  31                         operation.
  32   @param  CompareValue  64-bit value used in compare operation.
  33   @param  ExchangeValue 64-bit value used in exchange operation.
  34
  35   @return The original *Value before exchange.
  36
  37 **/
  38 UINT64
  39 EFIAPI
  40 InternalSyncCompareExchange64 (
  41   IN      volatile UINT64  *Value,
  42   IN      UINT64           CompareValue,
  43   IN      UINT64           ExchangeValue
  44   )
  45 {
  46   return _InterlockedCompareExchange64 (Value, ExchangeValue, CompareValue);
  47 }