SDL2/include/SDL_thread.h

/*
    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 */

/* vi: set ts=4 sw=4 expandtab: */