/* $Id: mthreads.h,v 1.2 1998/02/04 08:53:44 poliwoda Exp poliwoda $ */

/*
 * Mesa 3-D graphics library
 * Version:  2.6
 * Copyright (C) 1995-1998  Brian Paul
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * mthreads.h -- platform dependent thread support for Mesa 
 *
 * $Log$
 *
 * Initial version by John Stone (j.stone@acm.org) (johns@cs.umr.edu)
 *                and Christoph Poliwoda (poliwoda@volumegraphics.com)
 */


/*
 * 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.
 */
#ifdef THREADS
/*
 * It is an error not to select a specific threads API when compiling.
 */
#if !defined PTHREADS && !defined SOLARIS_THREADS && !defined WIN32
#error One of PTHREADS, SOLARIS_THREADS or WIN32 must be defined.
#endif


/*
 * Error messages which should be printed when our Mesa thread APIs fail
 * for one reason or another.
 */
#define MESA_INIT_TSD_ERROR "Mesa: thread failed to allocate key for thread specific data"
#define MESA_GET_TSD_ERROR "Mesa: thread failed to get thread specific data"
#define MESA_SET_TSD_ERROR "Mesa: thread failed to set thread specific data"


/*
 * magic number for win32 and solaris threads equivalents of pthread_once
 * This could probably be done better, but we haven't figured out how yet. 
 */
#define INITFUNC_CALLED_MAGIC 0xff8adc98




/*
 * POSIX threads. This should be your choice in the Unix world
 * whenever possible.  When building with POSIX threads, be sure
 * to any able 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.
 */
#ifdef PTHREADS
#include <pthread.h> /* POSIX threads headers */

typedef struct {
  pthread_key_t  key;
  pthread_once_t once;
} MesaTSD;

typedef pthread_mutex_t MesaMutex;
typedef pthread_t MesaThread;

#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.
 */
#ifdef SOLARIS_THREADS
#include <thread.h>

typedef struct {
  thread_key_t key;
  mutex_t      keylock;
  int          initfuncCalled;
} MesaTSD;

typedef mutex_t MesaMutex;
typedef thread_t MesaThread;

#endif /* SOLARIS_THREADS */




/*
 * Windows threads. Should work with Windows NT and 95. 
 * IMPORTANT: Link with multithreaded runtime library when THREADS are
 * used!
 */

#ifdef WIN32
#include <windows.h>

typedef struct {
  DWORD key;
  int   initfuncCalled;
} MesaTSD;

typedef CRITICAL_SECTION MesaMutex;
typedef HANDLE MesaThread;

#endif /* WIN32 */




/*
 * Platform independent thread specific data API. 
 */
void  MesaInitTSD(MesaTSD *);
void* MesaGetTSD (MesaTSD *);
void  MesaSetTSD (MesaTSD *, void *, void (*initfunc)(void));


/* 
 * The following APIs are preliminary.  They may be needed in 
 * future versions of Mesa.  
 */
#if 0

/*
 * Platform independent mutual exclusion lock API.
 */
void  MesaInitMutex    (MesaMutex *);
void  MesaDestroyMutex (MesaMutex *);
void  MesaLockMutex    (MesaMutex *);
void  MesaUnlockMutex  (MesaMutex *);

/* 
 * Platform independent thread management API.
 */
MesaThread  MesaCreateThread ((void*)(*)(void*), void*);
void        MesaJoinThread   (MesaThread);

#endif 

#endif /* THREADS */