MdePkg/Library/BaseSynchronizationLib/X64/InterlockedCompareExchange16.c

   1 /** @file
   2   InterlockedCompareExchange16 function
   3
   4   Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
   5   Copyright (c) 2015, Linaro Ltd. All rights reserved.<BR>
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 /**
  11   Microsoft Visual Studio 7.1 Function Prototypes for I/O Intrinsics.
  12 **/
  13
  14 __int16 _InterlockedCompareExchange16(
  15    __int16 volatile * Destination,
  16    __int16 Exchange,
  17    __int16 Comperand
  18 );
  19
  20 #pragma intrinsic(_InterlockedCompareExchange16)
  21
  22 /**
  23   Performs an atomic compare exchange operation on a 16-bit unsigned integer.
  24
  25   Performs an atomic compare exchange operation on the 16-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 16-bit value for the compare exchange
  31                         operation.
  32   @param  CompareValue  16-bit value used in compare operation.
  33   @param  ExchangeValue 16-bit value used in exchange operation.
  34
  35   @return The original *Value before exchange.
  36
  37 **/
  38 UINT16
  39 EFIAPI
  40 InternalSyncCompareExchange16 (
  41   IN      volatile UINT16           *Value,
  42   IN      UINT16                    CompareValue,
  43   IN      UINT16                    ExchangeValue
  44   )
  45 {
  46   return _InterlockedCompareExchange16 (Value, ExchangeValue, CompareValue);
  47 }
  48