view include/SDL_thread.h @ 3696:47d923feedb0

Fixed bug #935 Patrice Mandin Hello, I originally added pth support for threads in SDL 1.2 because on the Atari platform we did not have any thread library. I think pth support could be removed from SDL 1.3 for two reasons: - Atari platform removed - pth does not provides real (preemptive) threads, because it is user space, and expect the application to call one of its function to give CPU to another thread. So it is not exactly useful for applications, that expect threads to run simultaneously.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Jan 2010 20:47:20 +0000
parents 0d1b16ee0bca
children f7b03b6838cb
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifndef _SDL_thread_h
#define _SDL_thread_h

/**
 *  \file SDL_thread.h
 *  
 *  Header for the SDL thread management routines.
 */

#include "SDL_stdinc.h"
#include "SDL_error.h"

/* Thread synchronization primitives */
#include "SDL_mutex.h"

#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
/* *INDENT-OFF* */
extern "C" {
/* *INDENT-ON* */
#endif

/* The SDL thread structure, defined in SDL_thread.c */
struct SDL_Thread;
typedef struct SDL_Thread SDL_Thread;

/* The SDL thread ID */
typedef unsigned long SDL_threadID;

#if defined(__WIN32__) && !defined(HAVE_LIBC)
/**
 *  \file SDL_thread.h
 *  
 *  We compile SDL into a DLL. This means, that it's the DLL which
 *  creates a new thread for the calling process with the SDL_CreateThread()
 *  API. There is a problem with this, that only the RTL of the SDL.DLL will
 *  be initialized for those threads, and not the RTL of the calling 
 *  application!
 *  
 *  To solve this, we make a little hack here.
 *  
 *  We'll always use the caller's _beginthread() and _endthread() APIs to
 *  start a new thread. This way, if it's the SDL.DLL which uses this API,
 *  then the RTL of SDL.DLL will be used to create the new thread, and if it's
 *  the application, then the RTL of the application will be used.
 *  
 *  So, in short:
 *  Always use the _beginthread() and _endthread() of the calling runtime 
 *  library!
 */
#define SDL_PASSED_BEGINTHREAD_ENDTHREAD
#ifndef _WIN32_WCE
#include <process.h>            /* This has _beginthread() and _endthread() defined! */
#endif

#ifdef __GNUC__
typedef unsigned long (__cdecl * pfnSDL_CurrentBeginThread) (void *, unsigned,
                                                             unsigned
                                                             (__stdcall *
                                                              func) (void *),
                                                             void *arg,
                                                             unsigned,
                                                             unsigned
                                                             *threadID);
typedef void (__cdecl * pfnSDL_CurrentEndThread) (unsigned code);
#else
typedef uintptr_t(__cdecl * pfnSDL_CurrentBeginThread) (void *, unsigned,
                                                        unsigned (__stdcall *
                                                                  func) (void
                                                                         *),
                                                        void *arg, unsigned,
                                                        unsigned *threadID);
typedef void (__cdecl * pfnSDL_CurrentEndThread) (unsigned code);
#endif

/**
 *  Create a thread.
 */
extern DECLSPEC SDL_Thread *SDLCALL
SDL_CreateThread(int (SDLCALL * f) (void *), void *data,
                 pfnSDL_CurrentBeginThread pfnBeginThread,
                 pfnSDL_CurrentEndThread pfnEndThread);

#if defined(_WIN32_WCE)

/**
 *  Create a thread.
 */
#define SDL_CreateThread(fn, data) SDL_CreateThread(fn, data, NULL, NULL)

#else

/**
 *  Create a thread.
 */
#define SDL_CreateThread(fn, data) SDL_CreateThread(fn, data, _beginthreadex, _endthreadex)

#endif
#else

/**
 *  Create a thread.
 */
extern DECLSPEC SDL_Thread *SDLCALL
SDL_CreateThread(int (SDLCALL * fn) (void *), void *data);

#endif

/**
 *  Get the thread identifier for the current thread.
 */
extern DECLSPEC SDL_threadID SDLCALL SDL_ThreadID(void);

/**
 *  Get the thread identifier for the specified thread.
 *  
 *  Equivalent to SDL_ThreadID() if the specified thread is NULL.
 */
extern DECLSPEC SDL_threadID SDLCALL SDL_GetThreadID(SDL_Thread * thread);

/**
 *  Wait for a thread to finish.
 *  
 *  The return code for the thread function is placed in the area
 *  pointed to by \c status, if \c status is not NULL.
 */
extern DECLSPEC void SDLCALL SDL_WaitThread(SDL_Thread * thread, int *status);

/**
 *  \deprecated This function is here for binary compatibility with legacy apps,
 *              but in SDL 1.3 and later, it's a no-op.
 *  
 *  You cannot forcibly kill a thread in a safe manner on many platforms. You 
 *  should instead find a way to alert your thread that it is time to terminate,
 *  and then have it gracefully exit on its own. Do not ever call this function!
 */
extern DECLSPEC void SDLCALL SDL_KillThread(SDL_Thread * thread);


/* Ends C function definitions when using C++ */
#ifdef __cplusplus
/* *INDENT-OFF* */
}
/* *INDENT-ON* */
#endif
#include "close_code.h"

#endif /* _SDL_thread_h */

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