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- /*
- 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: */
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