glthread.h

/*
 * Mesa 3-D graphics library
 * Version:  6.5.2
 *
 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * Thread support for gl dispatch.
 *
 * Initial version by John Stone (j.stone@acm.org) (johns@cs.umr.edu)
 *                and Christoph Poliwoda (poliwoda@volumegraphics.com)
 * Revised by Keith Whitwell
 * Adapted for new gl dispatcher by Brian Paul
 *
 *
 *
 * DOCUMENTATION
 *
 * This thread module exports the following types:
 *   _glthread_TSD     Thread-specific data area
 *   _glthread_Thread  Thread datatype
 *   _glthread_Mutex   Mutual exclusion lock
 *
 * Macros:
 *   _glthread_DECLARE_STATIC_MUTEX(name)   Declare a non-local mutex
 *   _glthread_INIT_MUTEX(name)             Initialize a mutex
 *   _glthread_LOCK_MUTEX(name)             Lock a mutex
 *   _glthread_UNLOCK_MUTEX(name)           Unlock a mutex
 *
 * Functions:
 *   _glthread_GetID(v)      Get integer thread ID
 *   _glthread_InitTSD()     Initialize thread-specific data
 *   _glthread_GetTSD()      Get thread-specific data
 *   _glthread_SetTSD()      Set thread-specific data
 *
 */

/*
 * If this file is accidentally included by a non-threaded build,
 * it should not cause the build to fail, or otherwise cause problems.
 * In general, it should only be included when needed however.
 */

#ifndef GLTHREAD_H
#define GLTHREAD_H

#if defined(USE_MGL_NAMESPACE)
#define _glapi_Dispatch _mglapi_Dispatch
#endif

#if (defined(PTHREADS) || defined(WIN32_THREADS)) \
    && !defined(THREADS)
#define THREADS
#endif

#ifdef VMS
#include <GL/vms_x_fix.h>
#endif

/*
 * POSIX threads. This should be your choice in the Unix world
 * whenever possible.  When building with POSIX threads, be sure
 * to enable any compiler flags which will cause the MT-safe
 * libc (if one exists) to be used when linking, as well as any
 * header macros for MT-safe errno, etc.  For Solaris, this is the -mt
 * compiler flag.  On Solaris with gcc, use -D_REENTRANT to enable
 * proper compiling for MT-safe libc etc.
 */
#if defined(PTHREADS)
#include <pthread.h>            /* POSIX threads headers */

typedef struct {
    pthread_key_t key;
    int initMagic;
} _glthread_TSD;

typedef pthread_t _glthread_Thread;

typedef pthread_mutex_t _glthread_Mutex;

#define _glthread_DECLARE_STATIC_MUTEX(name) \
   static _glthread_Mutex name = PTHREAD_MUTEX_INITIALIZER

#define _glthread_INIT_MUTEX(name) \
   pthread_mutex_init(&(name), NULL)

#define _glthread_DESTROY_MUTEX(name) \
   pthread_mutex_destroy(&(name))

#define _glthread_LOCK_MUTEX(name) \
   (void) pthread_mutex_lock(&(name))

#define _glthread_UNLOCK_MUTEX(name) \
   (void) pthread_mutex_unlock(&(name))

#endif                          /* PTHREADS */

/*
 * Solaris threads. Use only up to Solaris 2.4.
 * Solaris 2.5 and higher provide POSIX threads.
 * Be sure to compile with -mt on the Solaris compilers, or
 * use -D_REENTRANT if using gcc.
 */

/*
 * Windows threads. Should work with Windows NT and 95.
 * IMPORTANT: Link with multithreaded runtime library when THREADS are
 * used!
 */
#ifdef WIN32_THREADS
#include <windows.h>

typedef struct {
    DWORD key;
    int initMagic;
} _glthread_TSD;

typedef HANDLE _glthread_Thread;

typedef CRITICAL_SECTION _glthread_Mutex;

#define _glthread_DECLARE_STATIC_MUTEX(name)  /*static*/ _glthread_Mutex name = {0,0,0,0,0,0}
#define _glthread_INIT_MUTEX(name)  InitializeCriticalSection(&name)
#define _glthread_DESTROY_MUTEX(name)  DeleteCriticalSection(&name)
#define _glthread_LOCK_MUTEX(name)  EnterCriticalSection(&name)
#define _glthread_UNLOCK_MUTEX(name)  LeaveCriticalSection(&name)

#endif                          /* WIN32_THREADS */

/*
 * BeOS threads. R5.x required.
 */
#ifdef BEOS_THREADS

#include <kernel/OS.h>
#include <support/TLS.h>

typedef struct {
    int32 key;
    int initMagic;
} _glthread_TSD;

typedef thread_id _glthread_Thread;

/* Use Benaphore, aka speeder semaphore */
typedef struct {
    int32 lock;
    sem_id sem;
} benaphore;
typedef benaphore _glthread_Mutex;

#define _glthread_DECLARE_STATIC_MUTEX(name)  static _glthread_Mutex name = { 0, 0 }
#define _glthread_INIT_MUTEX(name)    	name.sem = create_sem(0, #name"_benaphore"), name.lock = 0
#define _glthread_DESTROY_MUTEX(name) 	delete_sem(name.sem), name.lock = 0
#define _glthread_LOCK_MUTEX(name)    	if (name.sem == 0) _glthread_INIT_MUTEX(name); \
									  	if (atomic_add(&(name.lock), 1) >= 1) acquire_sem(name.sem)
#define _glthread_UNLOCK_MUTEX(name)  	if (atomic_add(&(name.lock), -1) > 1) release_sem(name.sem)

#endif                          /* BEOS_THREADS */

#ifndef THREADS

/*
 * THREADS not defined
 */

typedef int _glthread_TSD;

typedef int _glthread_Thread;

typedef int _glthread_Mutex;

#define _glthread_DECLARE_STATIC_MUTEX(name)  static _glthread_Mutex name = 0

#define _glthread_INIT_MUTEX(name)  (void) name

#define _glthread_DESTROY_MUTEX(name)  (void) name

#define _glthread_LOCK_MUTEX(name)  (void) name

#define _glthread_UNLOCK_MUTEX(name)  (void) name

#endif                          /* THREADS */

/*
 * Platform independent thread specific data API.
 */

extern unsigned long
 _glthread_GetID(void);

extern void
 _glthread_InitTSD(_glthread_TSD *);

extern void *_glthread_GetTSD(_glthread_TSD *);

extern void
 _glthread_SetTSD(_glthread_TSD *, void *);

#if defined(GLX_USE_TLS)

extern TLS struct _glapi_table *_glapi_tls_Dispatch;

#define GET_DISPATCH() _glapi_tls_Dispatch

#elif !defined(GL_CALL)
#if defined(THREADS)
#define GET_DISPATCH() \
   ((__builtin_expect( _glapi_Dispatch != NULL, 1 )) \
       ? _glapi_Dispatch : _glapi_get_dispatch())
#else
#define GET_DISPATCH() _glapi_Dispatch
#endif                          /* defined(THREADS) */
#endif                          /* ndef GL_CALL */

#endif                          /* THREADS_H */