3 * Copyright (C) 1998, 1999, 2000, 2001 ReactOS Team
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 * PROJECT: ReactOS kernel
22 * FILE: ntoskrnl/ex/fmutex.c
23 * PURPOSE: Implements fast mutexes
24 * PROGRAMMER: David Welch (welch@cwcom.net)
25 * PORTABILITY: Checked.
30 /* INCLUDES *****************************************************************/
33 #include <internal/debug.h>
35 /* FUNCTIONS *****************************************************************/
41 ExAcquireFastMutexUnsafe(PFAST_MUTEX FastMutex
)
43 ASSERT(FastMutex
->Owner
!= KeGetCurrentThread());
44 InterlockedIncrementUL(&FastMutex
->Contention
);
45 while (InterlockedExchange(&FastMutex
->Count
, 0) == 0)
47 KeWaitForSingleObject(&FastMutex
->Event
,
53 InterlockedDecrementUL(&FastMutex
->Contention
);
54 FastMutex
->Owner
= KeGetCurrentThread();
61 ExReleaseFastMutexUnsafe(PFAST_MUTEX FastMutex
)
63 ASSERT(FastMutex
->Owner
== KeGetCurrentThread());
64 FastMutex
->Owner
= NULL
;
65 InterlockedExchange(&FastMutex
->Count
, 1);
66 if (FastMutex
->Contention
> 0)
68 KeSetEvent(&FastMutex
->Event
, 0, FALSE
);