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			344 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			344 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|   Simple DirectMedia Layer
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|   Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
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| 
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|   This software is provided 'as-is', without any express or implied
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|   warranty.  In no event will the authors be held liable for any damages
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|   arising from the use of this software.
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| 
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|   Permission is granted to anyone to use this software for any purpose,
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|   including commercial applications, and to alter it and redistribute it
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|   freely, subject to the following restrictions:
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| 
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|   1. The origin of this software must not be misrepresented; you must not
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|      claim that you wrote the original software. If you use this software
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|      in a product, an acknowledgment in the product documentation would be
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|      appreciated but is not required.
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|   2. Altered source versions must be plainly marked as such, and must not be
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|      misrepresented as being the original software.
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|   3. This notice may not be removed or altered from any source distribution.
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| */
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| 
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| #ifndef SDL_thread_h_
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| #define SDL_thread_h_
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| 
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| /**
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|  *  \file SDL_thread.h
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|  *
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|  *  Header for the SDL thread management routines.
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|  */
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| 
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| #include "SDL_stdinc.h"
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| #include "SDL_error.h"
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| 
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| /* Thread synchronization primitives */
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| #include "SDL_atomic.h"
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| #include "SDL_mutex.h"
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| 
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| #include "begin_code.h"
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| /* Set up for C function definitions, even when using C++ */
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| #ifdef __cplusplus
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| extern "C" {
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| #endif
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| 
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| /* The SDL thread structure, defined in SDL_thread.c */
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| struct SDL_Thread;
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| typedef struct SDL_Thread SDL_Thread;
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| 
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| /* The SDL thread ID */
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| typedef unsigned long SDL_threadID;
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| 
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| /* Thread local storage ID, 0 is the invalid ID */
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| typedef unsigned int SDL_TLSID;
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| 
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| /**
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|  *  The SDL thread priority.
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|  *
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|  *  \note On many systems you require special privileges to set high or time critical priority.
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|  */
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| typedef enum {
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|     SDL_THREAD_PRIORITY_LOW,
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|     SDL_THREAD_PRIORITY_NORMAL,
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|     SDL_THREAD_PRIORITY_HIGH,
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|     SDL_THREAD_PRIORITY_TIME_CRITICAL
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| } SDL_ThreadPriority;
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| 
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| /**
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|  *  The function passed to SDL_CreateThread().
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|  *  It is passed a void* user context parameter and returns an int.
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|  */
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| typedef int (SDLCALL * SDL_ThreadFunction) (void *data);
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| 
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| #if defined(__WIN32__) && !defined(HAVE_LIBC)
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| /**
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|  *  \file SDL_thread.h
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|  *
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|  *  We compile SDL into a DLL. This means, that it's the DLL which
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|  *  creates a new thread for the calling process with the SDL_CreateThread()
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|  *  API. There is a problem with this, that only the RTL of the SDL2.DLL will
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|  *  be initialized for those threads, and not the RTL of the calling
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|  *  application!
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|  *
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|  *  To solve this, we make a little hack here.
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|  *
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|  *  We'll always use the caller's _beginthread() and _endthread() APIs to
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|  *  start a new thread. This way, if it's the SDL2.DLL which uses this API,
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|  *  then the RTL of SDL2.DLL will be used to create the new thread, and if it's
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|  *  the application, then the RTL of the application will be used.
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|  *
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|  *  So, in short:
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|  *  Always use the _beginthread() and _endthread() of the calling runtime
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|  *  library!
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|  */
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| #define SDL_PASSED_BEGINTHREAD_ENDTHREAD
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| #include <process.h> /* _beginthreadex() and _endthreadex() */
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| 
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| typedef uintptr_t(__cdecl * pfnSDL_CurrentBeginThread)
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|                    (void *, unsigned, unsigned (__stdcall *func)(void *),
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|                     void * /*arg*/, unsigned, unsigned * /* threadID */);
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| typedef void (__cdecl * pfnSDL_CurrentEndThread) (unsigned code);
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| 
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| /**
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|  *  Create a thread.
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|  */
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| extern DECLSPEC SDL_Thread *SDLCALL
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| SDL_CreateThread(SDL_ThreadFunction fn, const char *name, void *data,
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|                  pfnSDL_CurrentBeginThread pfnBeginThread,
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|                  pfnSDL_CurrentEndThread pfnEndThread);
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| 
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| extern DECLSPEC SDL_Thread *SDLCALL
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| SDL_CreateThreadWithStackSize(int (SDLCALL * fn) (void *),
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|                  const char *name, const size_t stacksize, void *data,
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|                  pfnSDL_CurrentBeginThread pfnBeginThread,
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|                  pfnSDL_CurrentEndThread pfnEndThread);
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| 
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| 
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| /**
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|  *  Create a thread.
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|  */
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| #if defined(SDL_CreateThread) && SDL_DYNAMIC_API
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| #undef SDL_CreateThread
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| #define SDL_CreateThread(fn, name, data) SDL_CreateThread_REAL(fn, name, data, (pfnSDL_CurrentBeginThread)_beginthreadex, (pfnSDL_CurrentEndThread)_endthreadex)
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| #undef SDL_CreateThreadWithStackSize
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| #define SDL_CreateThreadWithStackSize(fn, name, stacksize, data) SDL_CreateThreadWithStackSize_REAL(fn, name, stacksize, data, (pfnSDL_CurrentBeginThread)_beginthreadex, (pfnSDL_CurrentEndThread)_endthreadex)
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| #else
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| #define SDL_CreateThread(fn, name, data) SDL_CreateThread(fn, name, data, (pfnSDL_CurrentBeginThread)_beginthreadex, (pfnSDL_CurrentEndThread)_endthreadex)
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| #define SDL_CreateThreadWithStackSize(fn, name, stacksize, data) SDL_CreateThreadWithStackSize(fn, name, data, (pfnSDL_CurrentBeginThread)_beginthreadex, (pfnSDL_CurrentEndThread)_endthreadex)
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| #endif
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| 
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| #elif defined(__OS2__)
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| /*
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|  * just like the windows case above:  We compile SDL2
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|  * into a dll with Watcom's runtime statically linked.
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|  */
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| #define SDL_PASSED_BEGINTHREAD_ENDTHREAD
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| #ifndef __EMX__
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| #include <process.h>
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| #else
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| #include <stdlib.h>
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| #endif
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| typedef int (*pfnSDL_CurrentBeginThread)(void (*func)(void *), void *, unsigned, void * /*arg*/);
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| typedef void (*pfnSDL_CurrentEndThread)(void);
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| extern DECLSPEC SDL_Thread *SDLCALL
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| SDL_CreateThread(SDL_ThreadFunction fn, const char *name, void *data,
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|                  pfnSDL_CurrentBeginThread pfnBeginThread,
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|                  pfnSDL_CurrentEndThread pfnEndThread);
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| extern DECLSPEC SDL_Thread *SDLCALL
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| SDL_CreateThreadWithStackSize(SDL_ThreadFunction fn, const char *name, const size_t stacksize, void *data,
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|                  pfnSDL_CurrentBeginThread pfnBeginThread,
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|                  pfnSDL_CurrentEndThread pfnEndThread);
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| #if defined(SDL_CreateThread) && SDL_DYNAMIC_API
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| #undef SDL_CreateThread
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| #define SDL_CreateThread(fn, name, data) SDL_CreateThread_REAL(fn, name, data, (pfnSDL_CurrentBeginThread)_beginthread, (pfnSDL_CurrentEndThread)_endthread)
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| #undef SDL_CreateThreadWithStackSize
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| #define SDL_CreateThreadWithStackSize(fn, name, stacksize, data) SDL_CreateThreadWithStackSize_REAL(fn, name, data, (pfnSDL_CurrentBeginThread)_beginthread, (pfnSDL_CurrentEndThread)_endthread)
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| #else
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| #define SDL_CreateThread(fn, name, data) SDL_CreateThread(fn, name, data, (pfnSDL_CurrentBeginThread)_beginthread, (pfnSDL_CurrentEndThread)_endthread)
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| #define SDL_CreateThreadWithStackSize(fn, name, stacksize, data) SDL_CreateThreadWithStackSize(fn, name, stacksize, data, (pfnSDL_CurrentBeginThread)_beginthread, (pfnSDL_CurrentEndThread)_endthread)
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| #endif
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| 
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| #else
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| 
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| /**
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|  *  Create a thread with a default stack size.
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|  *
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|  *  This is equivalent to calling:
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|  *  SDL_CreateThreadWithStackSize(fn, name, 0, data);
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|  */
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| extern DECLSPEC SDL_Thread *SDLCALL
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| SDL_CreateThread(SDL_ThreadFunction fn, const char *name, void *data);
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| 
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| /**
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|  *  Create a thread.
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|  *
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|  *   Thread naming is a little complicated: Most systems have very small
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|  *    limits for the string length (Haiku has 32 bytes, Linux currently has 16,
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|  *    Visual C++ 6.0 has nine!), and possibly other arbitrary rules. You'll
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|  *    have to see what happens with your system's debugger. The name should be
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|  *    UTF-8 (but using the naming limits of C identifiers is a better bet).
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|  *   There are no requirements for thread naming conventions, so long as the
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|  *    string is null-terminated UTF-8, but these guidelines are helpful in
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|  *    choosing a name:
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|  *
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|  *    http://stackoverflow.com/questions/149932/naming-conventions-for-threads
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|  *
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|  *   If a system imposes requirements, SDL will try to munge the string for
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|  *    it (truncate, etc), but the original string contents will be available
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|  *    from SDL_GetThreadName().
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|  *
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|  *   The size (in bytes) of the new stack can be specified. Zero means "use
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|  *    the system default" which might be wildly different between platforms
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|  *    (x86 Linux generally defaults to eight megabytes, an embedded device
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|  *    might be a few kilobytes instead).
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|  *
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|  *   In SDL 2.1, stacksize will be folded into the original SDL_CreateThread
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|  *    function.
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|  */
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| extern DECLSPEC SDL_Thread *SDLCALL
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| SDL_CreateThreadWithStackSize(SDL_ThreadFunction fn, const char *name, const size_t stacksize, void *data);
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| 
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| #endif
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| 
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| /**
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|  * Get the thread name, as it was specified in SDL_CreateThread().
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|  *  This function returns a pointer to a UTF-8 string that names the
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|  *  specified thread, or NULL if it doesn't have a name. This is internal
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|  *  memory, not to be free()'d by the caller, and remains valid until the
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|  *  specified thread is cleaned up by SDL_WaitThread().
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|  */
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| extern DECLSPEC const char *SDLCALL SDL_GetThreadName(SDL_Thread *thread);
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| 
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| /**
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|  *  Get the thread identifier for the current thread.
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|  */
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| extern DECLSPEC SDL_threadID SDLCALL SDL_ThreadID(void);
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| 
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| /**
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|  *  Get the thread identifier for the specified thread.
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|  *
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|  *  Equivalent to SDL_ThreadID() if the specified thread is NULL.
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|  */
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| extern DECLSPEC SDL_threadID SDLCALL SDL_GetThreadID(SDL_Thread * thread);
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| 
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| /**
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|  *  Set the priority for the current thread
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|  */
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| extern DECLSPEC int SDLCALL SDL_SetThreadPriority(SDL_ThreadPriority priority);
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| 
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| /**
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|  *  Wait for a thread to finish. Threads that haven't been detached will
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|  *  remain (as a "zombie") until this function cleans them up. Not doing so
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|  *  is a resource leak.
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|  *
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|  *  Once a thread has been cleaned up through this function, the SDL_Thread
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|  *  that references it becomes invalid and should not be referenced again.
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|  *  As such, only one thread may call SDL_WaitThread() on another.
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|  *
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|  *  The return code for the thread function is placed in the area
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|  *  pointed to by \c status, if \c status is not NULL.
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|  *
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|  *  You may not wait on a thread that has been used in a call to
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|  *  SDL_DetachThread(). Use either that function or this one, but not
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|  *  both, or behavior is undefined.
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|  *
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|  *  It is safe to pass NULL to this function; it is a no-op.
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|  */
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| extern DECLSPEC void SDLCALL SDL_WaitThread(SDL_Thread * thread, int *status);
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| 
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| /**
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|  *  A thread may be "detached" to signify that it should not remain until
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|  *  another thread has called SDL_WaitThread() on it. Detaching a thread
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|  *  is useful for long-running threads that nothing needs to synchronize
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|  *  with or further manage. When a detached thread is done, it simply
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|  *  goes away.
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|  *
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|  *  There is no way to recover the return code of a detached thread. If you
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|  *  need this, don't detach the thread and instead use SDL_WaitThread().
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|  *
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|  *  Once a thread is detached, you should usually assume the SDL_Thread isn't
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|  *  safe to reference again, as it will become invalid immediately upon
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|  *  the detached thread's exit, instead of remaining until someone has called
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|  *  SDL_WaitThread() to finally clean it up. As such, don't detach the same
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|  *  thread more than once.
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|  *
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|  *  If a thread has already exited when passed to SDL_DetachThread(), it will
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|  *  stop waiting for a call to SDL_WaitThread() and clean up immediately.
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|  *  It is not safe to detach a thread that might be used with SDL_WaitThread().
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|  *
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|  *  You may not call SDL_WaitThread() on a thread that has been detached.
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|  *  Use either that function or this one, but not both, or behavior is
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|  *  undefined.
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|  *
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|  *  It is safe to pass NULL to this function; it is a no-op.
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|  */
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| extern DECLSPEC void SDLCALL SDL_DetachThread(SDL_Thread * thread);
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| 
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| /**
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|  *  \brief Create an identifier that is globally visible to all threads but refers to data that is thread-specific.
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|  *
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|  *  \return The newly created thread local storage identifier, or 0 on error
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|  *
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|  *  \code
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|  *  static SDL_SpinLock tls_lock;
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|  *  static SDL_TLSID thread_local_storage;
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|  * 
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|  *  void SetMyThreadData(void *value)
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|  *  {
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|  *      if (!thread_local_storage) {
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|  *          SDL_AtomicLock(&tls_lock);
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|  *          if (!thread_local_storage) {
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|  *              thread_local_storage = SDL_TLSCreate();
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|  *          }
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|  *          SDL_AtomicUnlock(&tls_lock);
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|  *      }
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|  *      SDL_TLSSet(thread_local_storage, value, 0);
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|  *  }
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|  *  
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|  *  void *GetMyThreadData(void)
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|  *  {
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|  *      return SDL_TLSGet(thread_local_storage);
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|  *  }
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|  *  \endcode
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|  *
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|  *  \sa SDL_TLSGet()
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|  *  \sa SDL_TLSSet()
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|  */
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| extern DECLSPEC SDL_TLSID SDLCALL SDL_TLSCreate(void);
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| 
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| /**
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|  *  \brief Get the value associated with a thread local storage ID for the current thread.
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|  *
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|  *  \param id The thread local storage ID
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|  *
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|  *  \return The value associated with the ID for the current thread, or NULL if no value has been set.
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|  *
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|  *  \sa SDL_TLSCreate()
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|  *  \sa SDL_TLSSet()
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|  */
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| extern DECLSPEC void * SDLCALL SDL_TLSGet(SDL_TLSID id);
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| 
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| /**
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|  *  \brief Set the value associated with a thread local storage ID for the current thread.
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|  *
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|  *  \param id The thread local storage ID
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|  *  \param value The value to associate with the ID for the current thread
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|  *  \param destructor A function called when the thread exits, to free the value.
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|  *
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|  *  \return 0 on success, -1 on error
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|  *
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|  *  \sa SDL_TLSCreate()
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|  *  \sa SDL_TLSGet()
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|  */
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| extern DECLSPEC int SDLCALL SDL_TLSSet(SDL_TLSID id, const void *value, void (SDLCALL *destructor)(void*));
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| 
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| 
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| /* Ends C function definitions when using C++ */
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| #ifdef __cplusplus
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| }
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| #endif
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| #include "close_code.h"
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| 
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| #endif /* SDL_thread_h_ */
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| 
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| /* vi: set ts=4 sw=4 expandtab: */
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