gecko-dev/modules/libnls/headers/muteximp.h
1998-05-27 02:02:27 +00:00

92 lines
3.2 KiB
C

/*
*****************************************************************************************
* *
* COPYRIGHT: *
* (C) Copyright Taligent, Inc., 1997 *
* (C) Copyright International Business Machines Corporation, 1997 *
* Licensed Material - Program-Property of IBM - All Rights Reserved. *
* US Government Users Restricted Rights - Use, duplication, or disclosure *
* restricted by GSA ADP Schedule Contract with IBM Corp. *
* *
*****************************************************************************************
*/
/*
* File: muteximp.h
*
* Simple mutex class which allows platform-independent thread safety. The
* burden is on the library caller to provide the actual locking implementation,
* if they need thread-safety. Clients who don't care don't need to do anything.
*
* Author: Alan Liu 1/31/97
* History: Helena Shih Updated 2/4/97
* 06/04/97 helena Updated comments as per feedback from 5/21 drop.
*/
#ifndef _MUTEXIMP
#define _MUTEXIMP
#include "ptypes.h"
/*
* Clients who wish to call the library from multiple threads should create a
* MutexImplementation struct, with three pointers in it, and then call
* Mutex::SetImplementation(). Clients are responsible for making this initial
* call thread-safe.
* Clients who don't care about thread safety don't have to do anything.
*/
typedef void* MutexPointer;
typedef void (*MutexFunction)(MutexPointer);
#ifdef XP_CPLUSPLUS
struct MutexImplementation
{
MutexPointer mutex; /* Pointer to the actual mutex object */
MutexFunction lock; /* Function to enter mutex */
MutexFunction unlock; /* Function to leave mutex */
};
#endif
#ifndef XP_CPLUSPLUS
typedef struct MutexImplementation
{
MutexPointer mutex; /* Pointer to the actual mutex object */
MutexFunction lock; /* Function to enter mutex */
MutexFunction unlock; /* Function to leave mutex */
} MutexImplementation;
#endif
/**
* The following is an example of the mutex implementation on Win32 platforms,
<pre>
. #include "mutex.h"
. #include &lt;WINDOWS.H>
.
. static CRITICAL_SECTION gMutex;
.
. void Win32Lock(MutexPointer p)
. {
. CRITICAL_SECTION *mutex = (CRITICAL_SECTION*)p;
. EnterCriticalSection(mutex);
. }
.
. void Win32Unlock(MutexPointer p)
. {
. CRITICAL_SECTION *mutex = (CRITICAL_SECTION*)p;
. LeaveCriticalSection(mutex);
. }
.
. MutexImplementation gWin32MutexImplementation = { &gMutex, Win32Lock, Win32Unlock };
. ....
.
. Maybe something like this: Client would write this function and then
. make sure to call it once in one thread before multiple threads start.
. ....
. void Win32MutexInitialize()
. {
. InitializeCriticalSection(&gMutex);
. Mutex::SetImplementation(&gWin32MutexImplementation);
. }
</pre>
*/
#endif