include/SDL_thread.h
author Sam Lantinga <slouken@libsdl.org>
Fri, 08 Apr 2011 13:03:26 -0700
changeset 5535 96594ac5fd1a
parent 5509 5b1b4d820d10
child 5904 a21d78fc998c
permissions -rw-r--r--
SDL 1.3 is now under the zlib license.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2011 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 #ifndef _SDL_thread_h
    23 #define _SDL_thread_h
    24 
    25 /**
    26  *  \file SDL_thread.h
    27  *  
    28  *  Header for the SDL thread management routines.
    29  */
    30 
    31 #include "SDL_stdinc.h"
    32 #include "SDL_error.h"
    33 
    34 /* Thread synchronization primitives */
    35 #include "SDL_mutex.h"
    36 
    37 #include "begin_code.h"
    38 /* Set up for C function definitions, even when using C++ */
    39 #ifdef __cplusplus
    40 /* *INDENT-OFF* */
    41 extern "C" {
    42 /* *INDENT-ON* */
    43 #endif
    44 
    45 /* The SDL thread structure, defined in SDL_thread.c */
    46 struct SDL_Thread;
    47 typedef struct SDL_Thread SDL_Thread;
    48 
    49 /* The SDL thread ID */
    50 typedef unsigned long SDL_threadID;
    51 
    52 /* The SDL thread priority
    53  *
    54  * Note: On many systems you require special privileges to set high priority.
    55  */
    56 typedef enum {
    57     SDL_THREAD_PRIORITY_LOW,
    58     SDL_THREAD_PRIORITY_NORMAL,
    59     SDL_THREAD_PRIORITY_HIGH
    60 } SDL_ThreadPriority;
    61 
    62 /* The function passed to SDL_CreateThread()
    63    It is passed a void* user context parameter and returns an int.
    64  */
    65 typedef int (SDLCALL * SDL_ThreadFunction) (void *data);
    66 
    67 #if defined(__WIN32__) && !defined(HAVE_LIBC)
    68 /**
    69  *  \file SDL_thread.h
    70  *  
    71  *  We compile SDL into a DLL. This means, that it's the DLL which
    72  *  creates a new thread for the calling process with the SDL_CreateThread()
    73  *  API. There is a problem with this, that only the RTL of the SDL.DLL will
    74  *  be initialized for those threads, and not the RTL of the calling 
    75  *  application!
    76  *  
    77  *  To solve this, we make a little hack here.
    78  *  
    79  *  We'll always use the caller's _beginthread() and _endthread() APIs to
    80  *  start a new thread. This way, if it's the SDL.DLL which uses this API,
    81  *  then the RTL of SDL.DLL will be used to create the new thread, and if it's
    82  *  the application, then the RTL of the application will be used.
    83  *  
    84  *  So, in short:
    85  *  Always use the _beginthread() and _endthread() of the calling runtime 
    86  *  library!
    87  */
    88 #define SDL_PASSED_BEGINTHREAD_ENDTHREAD
    89 #ifndef _WIN32_WCE
    90 #include <process.h>            /* This has _beginthread() and _endthread() defined! */
    91 #endif
    92 
    93 #ifdef __GNUC__
    94 typedef unsigned long (__cdecl * pfnSDL_CurrentBeginThread) (void *, unsigned,
    95                                                              unsigned
    96                                                              (__stdcall *
    97                                                               func) (void *),
    98                                                              void *arg,
    99                                                              unsigned,
   100                                                              unsigned
   101                                                              *threadID);
   102 typedef void (__cdecl * pfnSDL_CurrentEndThread) (unsigned code);
   103 #else
   104 typedef uintptr_t(__cdecl * pfnSDL_CurrentBeginThread) (void *, unsigned,
   105                                                         unsigned (__stdcall *
   106                                                                   func) (void
   107                                                                          *),
   108                                                         void *arg, unsigned,
   109                                                         unsigned *threadID);
   110 typedef void (__cdecl * pfnSDL_CurrentEndThread) (unsigned code);
   111 #endif
   112 
   113 /**
   114  *  Create a thread.
   115  */
   116 extern DECLSPEC SDL_Thread *SDLCALL
   117 SDL_CreateThread(SDL_ThreadFunction fn, void *data,
   118                  pfnSDL_CurrentBeginThread pfnBeginThread,
   119                  pfnSDL_CurrentEndThread pfnEndThread);
   120 
   121 #if defined(_WIN32_WCE)
   122 
   123 /**
   124  *  Create a thread.
   125  */
   126 #define SDL_CreateThread(fn, data) SDL_CreateThread(fn, data, NULL, NULL)
   127 
   128 #else
   129 
   130 /**
   131  *  Create a thread.
   132  */
   133 #define SDL_CreateThread(fn, data) SDL_CreateThread(fn, data, _beginthreadex, _endthreadex)
   134 
   135 #endif
   136 #else
   137 
   138 /**
   139  *  Create a thread.
   140  */
   141 extern DECLSPEC SDL_Thread *SDLCALL
   142 SDL_CreateThread(SDL_ThreadFunction fn, void *data);
   143 
   144 #endif
   145 
   146 /**
   147  *  Get the thread identifier for the current thread.
   148  */
   149 extern DECLSPEC SDL_threadID SDLCALL SDL_ThreadID(void);
   150 
   151 /**
   152  *  Get the thread identifier for the specified thread.
   153  *  
   154  *  Equivalent to SDL_ThreadID() if the specified thread is NULL.
   155  */
   156 extern DECLSPEC SDL_threadID SDLCALL SDL_GetThreadID(SDL_Thread * thread);
   157 
   158 /**
   159  *  Set the priority for the current thread
   160  */
   161 extern DECLSPEC int SDLCALL SDL_SetThreadPriority(SDL_ThreadPriority priority);
   162 
   163 /**
   164  *  Wait for a thread to finish.
   165  *  
   166  *  The return code for the thread function is placed in the area
   167  *  pointed to by \c status, if \c status is not NULL.
   168  */
   169 extern DECLSPEC void SDLCALL SDL_WaitThread(SDL_Thread * thread, int *status);
   170 
   171 
   172 /* Ends C function definitions when using C++ */
   173 #ifdef __cplusplus
   174 /* *INDENT-OFF* */
   175 }
   176 /* *INDENT-ON* */
   177 #endif
   178 #include "close_code.h"
   179 
   180 #endif /* _SDL_thread_h */
   181 
   182 /* vi: set ts=4 sw=4 expandtab: */