hal/halx86/fmutex.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/hal/x86/fmutex.c
   6  * PURPOSE:         Implements fast mutexes
   7  * PROGRAMMER:      David Welch (welch@cwcom.net)
   8  *                  Eric Kohl (ekohl@rz-online.de)
   9  * UPDATE HISTORY:
  10  *                  Created 09/06/2000
  11  */
  12
  13 /* INCLUDES *****************************************************************/
  14
  15 #include <ddk/ntddk.h>
  16
  17 #include <internal/debug.h>
  18
  19 /* FUNCTIONS *****************************************************************/
  20
  21 VOID FASTCALL
  22 ExAcquireFastMutex (PFAST_MUTEX FastMutex)
  23 {
  24    KeEnterCriticalRegion();
  25    ExAcquireFastMutexUnsafe(FastMutex);
  26 }
  27
  28
  29 VOID FASTCALL
  30 ExReleaseFastMutex (PFAST_MUTEX FastMutex)
  31 {
  32   ExReleaseFastMutexUnsafe(FastMutex);
  33   KeLeaveCriticalRegion();
  34 }
  35
  36
  37 BOOLEAN FASTCALL
  38 ExTryToAcquireFastMutex (PFAST_MUTEX FastMutex)
  39 {
  40   KeEnterCriticalRegion();
  41   if (InterlockedExchange(&FastMutex->Count, 0) == 1)
  42     {
  43       FastMutex->Owner = KeGetCurrentThread();
  44       return(TRUE);
  45     }
  46   else
  47     {
  48       KeLeaveCriticalRegion();
  49       return(FALSE);
  50     }
  51 }
  52
  53 /* EOF */