| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org> |
| |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| 2. Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| |
| #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_atomic.h" |
| #include "SDL_mutex.h" |
| |
| #if defined(__WIN32__) || defined(__GDK__) |
| #include <process.h> /* _beginthreadex() and _endthreadex() */ |
| #endif |
| #if defined(__OS2__) /* for _beginthread() and _endthread() */ |
| #ifndef __EMX__ |
| #include <process.h> |
| #else |
| #include <stdlib.h> |
| #endif |
| #endif |
| |
| #include "begin_code.h" |
| /* Set up for C function definitions, even when using C++ */ |
| #ifdef __cplusplus |
| extern "C" { |
| #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; |
| |
| /* Thread local storage ID, 0 is the invalid ID */ |
| typedef unsigned int SDL_TLSID; |
| |
| /** |
| * The SDL thread priority. |
| * |
| * SDL will make system changes as necessary in order to apply the thread priority. |
| * Code which attempts to control thread state related to priority should be aware |
| * that calling SDL_SetThreadPriority may alter such state. |
| * SDL_HINT_THREAD_PRIORITY_POLICY can be used to control aspects of this behavior. |
| * |
| * \note On many systems you require special privileges to set high or time critical priority. |
| */ |
| typedef enum { |
| SDL_THREAD_PRIORITY_LOW, |
| SDL_THREAD_PRIORITY_NORMAL, |
| SDL_THREAD_PRIORITY_HIGH, |
| SDL_THREAD_PRIORITY_TIME_CRITICAL |
| } SDL_ThreadPriority; |
| |
| /** |
| * The function passed to SDL_CreateThread(). |
| * |
| * \param data what was passed as `data` to SDL_CreateThread() |
| * \returns a value that can be reported through SDL_WaitThread(). |
| */ |
| typedef int (SDLCALL * SDL_ThreadFunction) (void *data); |
| |
| |
| #if defined(__WIN32__) || defined(__GDK__) |
| /** |
| * \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 SDL2.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 SDL2.DLL which uses this API, |
| * then the RTL of SDL2.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 |
| |
| typedef uintptr_t (__cdecl * pfnSDL_CurrentBeginThread) |
| (void *, unsigned, unsigned (__stdcall *func)(void *), |
| void * /*arg*/, unsigned, unsigned * /* threadID */); |
| typedef void (__cdecl * pfnSDL_CurrentEndThread) (unsigned code); |
| |
| #ifndef SDL_beginthread |
| #define SDL_beginthread _beginthreadex |
| #endif |
| #ifndef SDL_endthread |
| #define SDL_endthread _endthreadex |
| #endif |
| |
| extern DECLSPEC SDL_Thread *SDLCALL |
| SDL_CreateThread(SDL_ThreadFunction fn, const char *name, void *data, |
| pfnSDL_CurrentBeginThread pfnBeginThread, |
| pfnSDL_CurrentEndThread pfnEndThread); |
| |
| extern DECLSPEC SDL_Thread *SDLCALL |
| SDL_CreateThreadWithStackSize(SDL_ThreadFunction fn, |
| const char *name, const size_t stacksize, void *data, |
| pfnSDL_CurrentBeginThread pfnBeginThread, |
| pfnSDL_CurrentEndThread pfnEndThread); |
| |
| |
| #if defined(SDL_CreateThread) && SDL_DYNAMIC_API |
| #undef SDL_CreateThread |
| #define SDL_CreateThread(fn, name, data) SDL_CreateThread_REAL(fn, name, data, (pfnSDL_CurrentBeginThread)SDL_beginthread, (pfnSDL_CurrentEndThread)SDL_endthread) |
| #undef SDL_CreateThreadWithStackSize |
| #define SDL_CreateThreadWithStackSize(fn, name, stacksize, data) SDL_CreateThreadWithStackSize_REAL(fn, name, stacksize, data, (pfnSDL_CurrentBeginThread)SDL_beginthread, (pfnSDL_CurrentEndThread)SDL_endthread) |
| #else |
| #define SDL_CreateThread(fn, name, data) SDL_CreateThread(fn, name, data, (pfnSDL_CurrentBeginThread)SDL_beginthread, (pfnSDL_CurrentEndThread)SDL_endthread) |
| #define SDL_CreateThreadWithStackSize(fn, name, stacksize, data) SDL_CreateThreadWithStackSize(fn, name, stacksize, data, (pfnSDL_CurrentBeginThread)SDL_beginthread, (pfnSDL_CurrentEndThread)SDL_endthread) |
| #endif |
| |
| #elif defined(__OS2__) |
| /* |
| * just like the windows case above: We compile SDL2 |
| * into a dll with Watcom's runtime statically linked. |
| */ |
| #define SDL_PASSED_BEGINTHREAD_ENDTHREAD |
| |
| typedef int (*pfnSDL_CurrentBeginThread)(void (*func)(void *), void *, unsigned, void * /*arg*/); |
| typedef void (*pfnSDL_CurrentEndThread)(void); |
| |
| #ifndef SDL_beginthread |
| #define SDL_beginthread _beginthread |
| #endif |
| #ifndef SDL_endthread |
| #define SDL_endthread _endthread |
| #endif |
| |
| extern DECLSPEC SDL_Thread *SDLCALL |
| SDL_CreateThread(SDL_ThreadFunction fn, const char *name, void *data, |
| pfnSDL_CurrentBeginThread pfnBeginThread, |
| pfnSDL_CurrentEndThread pfnEndThread); |
| extern DECLSPEC SDL_Thread *SDLCALL |
| SDL_CreateThreadWithStackSize(SDL_ThreadFunction fn, const char *name, const size_t stacksize, void *data, |
| pfnSDL_CurrentBeginThread pfnBeginThread, |
| pfnSDL_CurrentEndThread pfnEndThread); |
| |
| #if defined(SDL_CreateThread) && SDL_DYNAMIC_API |
| #undef SDL_CreateThread |
| #define SDL_CreateThread(fn, name, data) SDL_CreateThread_REAL(fn, name, data, (pfnSDL_CurrentBeginThread)SDL_beginthread, (pfnSDL_CurrentEndThread)SDL_endthread) |
| #undef SDL_CreateThreadWithStackSize |
| #define SDL_CreateThreadWithStackSize(fn, name, stacksize, data) SDL_CreateThreadWithStackSize_REAL(fn, name, stacksize, data, (pfnSDL_CurrentBeginThread)SDL_beginthread, (pfnSDL_CurrentEndThread)SDL_endthread) |
| #else |
| #define SDL_CreateThread(fn, name, data) SDL_CreateThread(fn, name, data, (pfnSDL_CurrentBeginThread)SDL_beginthread, (pfnSDL_CurrentEndThread)SDL_endthread) |
| #define SDL_CreateThreadWithStackSize(fn, name, stacksize, data) SDL_CreateThreadWithStackSize(fn, name, stacksize, data, (pfnSDL_CurrentBeginThread)SDL_beginthread, (pfnSDL_CurrentEndThread)SDL_endthread) |
| #endif |
| |
| #else |
| |
| /** |
| * Create a new thread with a default stack size. |
| * |
| * This is equivalent to calling: |
| * |
| * ```c |
| * SDL_CreateThreadWithStackSize(fn, name, 0, data); |
| * ``` |
| * |
| * \param fn the SDL_ThreadFunction function to call in the new thread |
| * \param name the name of the thread |
| * \param data a pointer that is passed to `fn` |
| * \returns an opaque pointer to the new thread object on success, NULL if the |
| * new thread could not be created; call SDL_GetError() for more |
| * information. |
| * |
| * \since This function is available since SDL 2.0.0. |
| * |
| * \sa SDL_CreateThreadWithStackSize |
| * \sa SDL_WaitThread |
| */ |
| extern DECLSPEC SDL_Thread *SDLCALL |
| SDL_CreateThread(SDL_ThreadFunction fn, const char *name, void *data); |
| |
| /** |
| * Create a new thread with a specific stack size. |
| * |
| * SDL makes an attempt to report `name` to the system, so that debuggers can |
| * display it. Not all platforms support this. |
| * |
| * Thread naming is a little complicated: Most systems have very small limits |
| * for the string length (Haiku has 32 bytes, Linux currently has 16, Visual |
| * C++ 6.0 has _nine_!), and possibly other arbitrary rules. You'll have to |
| * see what happens with your system's debugger. The name should be UTF-8 (but |
| * using the naming limits of C identifiers is a better bet). There are no |
| * requirements for thread naming conventions, so long as the string is |
| * null-terminated UTF-8, but these guidelines are helpful in choosing a name: |
| * |
| * https://stackoverflow.com/questions/149932/naming-conventions-for-threads |
| * |
| * If a system imposes requirements, SDL will try to munge the string for it |
| * (truncate, etc), but the original string contents will be available from |
| * SDL_GetThreadName(). |
| * |
| * The size (in bytes) of the new stack can be specified. Zero means "use the |
| * system default" which might be wildly different between platforms. x86 |
| * Linux generally defaults to eight megabytes, an embedded device might be a |
| * few kilobytes instead. You generally need to specify a stack that is a |
| * multiple of the system's page size (in many cases, this is 4 kilobytes, but |
| * check your system documentation). |
| * |
| * In SDL 2.1, stack size will be folded into the original SDL_CreateThread |
| * function, but for backwards compatibility, this is currently a separate |
| * function. |
| * |
| * \param fn the SDL_ThreadFunction function to call in the new thread |
| * \param name the name of the thread |
| * \param stacksize the size, in bytes, to allocate for the new thread stack. |
| * \param data a pointer that is passed to `fn` |
| * \returns an opaque pointer to the new thread object on success, NULL if the |
| * new thread could not be created; call SDL_GetError() for more |
| * information. |
| * |
| * \since This function is available since SDL 2.0.9. |
| * |
| * \sa SDL_WaitThread |
| */ |
| extern DECLSPEC SDL_Thread *SDLCALL |
| SDL_CreateThreadWithStackSize(SDL_ThreadFunction fn, const char *name, const size_t stacksize, void *data); |
| |
| #endif |
| |
| /** |
| * Get the thread name as it was specified in SDL_CreateThread(). |
| * |
| * This is internal memory, not to be freed by the caller, and remains valid |
| * until the specified thread is cleaned up by SDL_WaitThread(). |
| * |
| * \param thread the thread to query |
| * \returns a pointer to a UTF-8 string that names the specified thread, or |
| * NULL if it doesn't have a name. |
| * |
| * \since This function is available since SDL 2.0.0. |
| * |
| * \sa SDL_CreateThread |
| */ |
| extern DECLSPEC const char *SDLCALL SDL_GetThreadName(SDL_Thread *thread); |
| |
| /** |
| * Get the thread identifier for the current thread. |
| * |
| * This thread identifier is as reported by the underlying operating system. |
| * If SDL is running on a platform that does not support threads the return |
| * value will always be zero. |
| * |
| * This function also returns a valid thread ID when called from the main |
| * thread. |
| * |
| * \returns the ID of the current thread. |
| * |
| * \since This function is available since SDL 2.0.0. |
| * |
| * \sa SDL_GetThreadID |
| */ |
| extern DECLSPEC SDL_threadID SDLCALL SDL_ThreadID(void); |
| |
| /** |
| * Get the thread identifier for the specified thread. |
| * |
| * This thread identifier is as reported by the underlying operating system. |
| * If SDL is running on a platform that does not support threads the return |
| * value will always be zero. |
| * |
| * \param thread the thread to query |
| * \returns the ID of the specified thread, or the ID of the current thread if |
| * `thread` is NULL. |
| * |
| * \since This function is available since SDL 2.0.0. |
| * |
| * \sa SDL_ThreadID |
| */ |
| extern DECLSPEC SDL_threadID SDLCALL SDL_GetThreadID(SDL_Thread * thread); |
| |
| /** |
| * Set the priority for the current thread. |
| * |
| * Note that some platforms will not let you alter the priority (or at least, |
| * promote the thread to a higher priority) at all, and some require you to be |
| * an administrator account. Be prepared for this to fail. |
| * |
| * \param priority the SDL_ThreadPriority to set |
| * \returns 0 on success or a negative error code on failure; call |
| * SDL_GetError() for more information. |
| * |
| * \since This function is available since SDL 2.0.0. |
| */ |
| extern DECLSPEC int SDLCALL SDL_SetThreadPriority(SDL_ThreadPriority priority); |
| |
| /** |
| * Wait for a thread to finish. |
| * |
| * Threads that haven't been detached will remain (as a "zombie") until this |
| * function cleans them up. Not doing so is a resource leak. |
| * |
| * Once a thread has been cleaned up through this function, the SDL_Thread |
| * that references it becomes invalid and should not be referenced again. As |
| * such, only one thread may call SDL_WaitThread() on another. |
| * |
| * The return code for the thread function is placed in the area pointed to by |
| * `status`, if `status` is not NULL. |
| * |
| * You may not wait on a thread that has been used in a call to |
| * SDL_DetachThread(). Use either that function or this one, but not both, or |
| * behavior is undefined. |
| * |
| * It is safe to pass a NULL thread to this function; it is a no-op. |
| * |
| * Note that the thread pointer is freed by this function and is not valid |
| * afterward. |
| * |
| * \param thread the SDL_Thread pointer that was returned from the |
| * SDL_CreateThread() call that started this thread |
| * \param status pointer to an integer that will receive the value returned |
| * from the thread function by its 'return', or NULL to not |
| * receive such value back. |
| * |
| * \since This function is available since SDL 2.0.0. |
| * |
| * \sa SDL_CreateThread |
| * \sa SDL_DetachThread |
| */ |
| extern DECLSPEC void SDLCALL SDL_WaitThread(SDL_Thread * thread, int *status); |
| |
| /** |
| * Let a thread clean up on exit without intervention. |
| * |
| * A thread may be "detached" to signify that it should not remain until |
| * another thread has called SDL_WaitThread() on it. Detaching a thread is |
| * useful for long-running threads that nothing needs to synchronize with or |
| * further manage. When a detached thread is done, it simply goes away. |
| * |
| * There is no way to recover the return code of a detached thread. If you |
| * need this, don't detach the thread and instead use SDL_WaitThread(). |
| * |
| * Once a thread is detached, you should usually assume the SDL_Thread isn't |
| * safe to reference again, as it will become invalid immediately upon the |
| * detached thread's exit, instead of remaining until someone has called |
| * SDL_WaitThread() to finally clean it up. As such, don't detach the same |
| * thread more than once. |
| * |
| * If a thread has already exited when passed to SDL_DetachThread(), it will |
| * stop waiting for a call to SDL_WaitThread() and clean up immediately. It is |
| * not safe to detach a thread that might be used with SDL_WaitThread(). |
| * |
| * You may not call SDL_WaitThread() on a thread that has been detached. Use |
| * either that function or this one, but not both, or behavior is undefined. |
| * |
| * It is safe to pass NULL to this function; it is a no-op. |
| * |
| * \param thread the SDL_Thread pointer that was returned from the |
| * SDL_CreateThread() call that started this thread |
| * |
| * \since This function is available since SDL 2.0.2. |
| * |
| * \sa SDL_CreateThread |
| * \sa SDL_WaitThread |
| */ |
| extern DECLSPEC void SDLCALL SDL_DetachThread(SDL_Thread * thread); |
| |
| /** |
| * Create a piece of thread-local storage. |
| * |
| * This creates an identifier that is globally visible to all threads but |
| * refers to data that is thread-specific. |
| * |
| * \returns the newly created thread local storage identifier or 0 on error. |
| * |
| * \since This function is available since SDL 2.0.0. |
| * |
| * \sa SDL_TLSGet |
| * \sa SDL_TLSSet |
| */ |
| extern DECLSPEC SDL_TLSID SDLCALL SDL_TLSCreate(void); |
| |
| /** |
| * Get the current thread's value associated with a thread local storage ID. |
| * |
| * \param id the thread local storage ID |
| * \returns the value associated with the ID for the current thread or NULL if |
| * no value has been set; call SDL_GetError() for more information. |
| * |
| * \since This function is available since SDL 2.0.0. |
| * |
| * \sa SDL_TLSCreate |
| * \sa SDL_TLSSet |
| */ |
| extern DECLSPEC void * SDLCALL SDL_TLSGet(SDL_TLSID id); |
| |
| /** |
| * Set the current thread's value associated with a thread local storage ID. |
| * |
| * The function prototype for `destructor` is: |
| * |
| * ```c |
| * void destructor(void *value) |
| * ``` |
| * |
| * where its parameter `value` is what was passed as `value` to SDL_TLSSet(). |
| * |
| * \param id the thread local storage ID |
| * \param value the value to associate with the ID for the current thread |
| * \param destructor a function called when the thread exits, to free the |
| * value |
| * \returns 0 on success or a negative error code on failure; call |
| * SDL_GetError() for more information. |
| * |
| * \since This function is available since SDL 2.0.0. |
| * |
| * \sa SDL_TLSCreate |
| * \sa SDL_TLSGet |
| */ |
| extern DECLSPEC int SDLCALL SDL_TLSSet(SDL_TLSID id, const void *value, void (SDLCALL *destructor)(void*)); |
| |
| /** |
| * Cleanup all TLS data for this thread. |
| * |
| * \since This function is available since SDL 2.0.16. |
| */ |
| extern DECLSPEC void SDLCALL SDL_TLSCleanup(void); |
| |
| /* Ends C function definitions when using C++ */ |
| #ifdef __cplusplus |
| } |
| #endif |
| #include "close_code.h" |
| |
| #endif /* SDL_thread_h_ */ |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |