diff options
author | Fox Caminiti <fox@foxcam.net> | 2022-12-22 13:29:02 -0500 |
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committer | Fox Caminiti <fox@foxcam.net> | 2022-12-22 13:29:02 -0500 |
commit | 375c120d30456738897c4bd775e38aa1db7d239c (patch) | |
tree | 5b365a6233cf736db15fa52fcfac4ba80a986217 /dependencies/include/SDL/SDL_thread.h | |
parent | 4854647d659f75ac6cf4575b61d1dcfd25865791 (diff) |
v3.1
Diffstat (limited to 'dependencies/include/SDL/SDL_thread.h')
-rw-r--r-- | dependencies/include/SDL/SDL_thread.h | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/dependencies/include/SDL/SDL_thread.h b/dependencies/include/SDL/SDL_thread.h new file mode 100644 index 0000000..7364f81 --- /dev/null +++ b/dependencies/include/SDL/SDL_thread.h @@ -0,0 +1,464 @@ +/* + 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, data, (pfnSDL_CurrentBeginThread)_beginthreadex, (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, 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: */ |