diff options
author | wm4 <nfxjfg@googlemail.com> | 2017-12-21 22:23:14 +0300 |
---|---|---|
committer | wm4 <nfxjfg@googlemail.com> | 2017-12-26 04:49:48 +0300 |
commit | 9b121dfc32810250938021952aab4172a988cb56 (patch) | |
tree | 4ba00da9da3be930ef112c7e802d3ed12744bef8 /compat/w32pthreads.h | |
parent | 2aee5a87233277027bb281372f888b5246a58e77 (diff) |
w32pthreads: always use Vista+ API, drop XP support
This removes the XP compatibility code, and switches entirely to SWR
locks, which are available starting at Windows Vista.
This removes CRITICAL_SECTION use, which allows us to add
PTHREAD_MUTEX_INITIALIZER, which will be useful later.
Windows XP is hereby not a supported build target anymore. It was
decided in a project vote that this is OK.
Diffstat (limited to 'compat/w32pthreads.h')
-rw-r--r-- | compat/w32pthreads.h | 266 |
1 files changed, 10 insertions, 256 deletions
diff --git a/compat/w32pthreads.h b/compat/w32pthreads.h index eeead6051f..237cab5677 100644 --- a/compat/w32pthreads.h +++ b/compat/w32pthreads.h @@ -56,19 +56,12 @@ typedef struct pthread_t { void *ret; } pthread_t; -/* the conditional variable api for windows 6.0+ uses critical sections and - * not mutexes */ -typedef CRITICAL_SECTION pthread_mutex_t; - -/* This is the CONDITION_VARIABLE typedef for using Windows' native - * conditional variables on kernels 6.0+. */ -#if HAVE_CONDITION_VARIABLE_PTR +/* use light weight mutex/condition variable API for Windows Vista and later */ +typedef SRWLOCK pthread_mutex_t; typedef CONDITION_VARIABLE pthread_cond_t; -#else -typedef struct pthread_cond_t { - void *Ptr; -} pthread_cond_t; -#endif + +#define PTHREAD_MUTEX_INITIALIZER SRWLOCK_INIT +#define PTHREAD_COND_INITIALIZER CONDITION_VARIABLE_INIT #if _WIN32_WINNT >= 0x0600 #define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0) @@ -114,26 +107,25 @@ static av_unused int pthread_join(pthread_t thread, void **value_ptr) static inline int pthread_mutex_init(pthread_mutex_t *m, void* attr) { - InitializeCriticalSection(m); + InitializeSRWLock(m); return 0; } static inline int pthread_mutex_destroy(pthread_mutex_t *m) { - DeleteCriticalSection(m); + /* Unlocked SWR locks use no resources */ return 0; } static inline int pthread_mutex_lock(pthread_mutex_t *m) { - EnterCriticalSection(m); + AcquireSRWLockExclusive(m); return 0; } static inline int pthread_mutex_unlock(pthread_mutex_t *m) { - LeaveCriticalSection(m); + ReleaseSRWLockExclusive(m); return 0; } -#if _WIN32_WINNT >= 0x0600 typedef INIT_ONCE pthread_once_t; #define PTHREAD_ONCE_INIT INIT_ONCE_STATIC_INIT @@ -167,7 +159,7 @@ static inline int pthread_cond_broadcast(pthread_cond_t *cond) static inline int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex) { - SleepConditionVariableCS(cond, mutex, INFINITE); + SleepConditionVariableSRW(cond, mutex, INFINITE, 0); return 0; } @@ -177,242 +169,4 @@ static inline int pthread_cond_signal(pthread_cond_t *cond) return 0; } -#else // _WIN32_WINNT < 0x0600 - -/* atomic init state of dynamically loaded functions */ -static LONG w32thread_init_state = 0; -static av_unused void w32thread_init(void); - -/* for pre-Windows 6.0 platforms, define INIT_ONCE struct, - * compatible to the one used in the native API */ - -typedef union pthread_once_t { - void * Ptr; ///< For the Windows 6.0+ native functions - LONG state; ///< For the pre-Windows 6.0 compat code -} pthread_once_t; - -#define PTHREAD_ONCE_INIT {0} - -/* function pointers to init once API on windows 6.0+ kernels */ -static BOOL (WINAPI *initonce_begin)(pthread_once_t *lpInitOnce, DWORD dwFlags, BOOL *fPending, void **lpContext); -static BOOL (WINAPI *initonce_complete)(pthread_once_t *lpInitOnce, DWORD dwFlags, void *lpContext); - -/* pre-Windows 6.0 compat using a spin-lock */ -static inline void w32thread_once_fallback(LONG volatile *state, void (*init_routine)(void)) -{ - switch (InterlockedCompareExchange(state, 1, 0)) { - /* Initial run */ - case 0: - init_routine(); - InterlockedExchange(state, 2); - break; - /* Another thread is running init */ - case 1: - while (1) { - MemoryBarrier(); - if (*state == 2) - break; - Sleep(0); - } - break; - /* Initialization complete */ - case 2: - break; - } -} - -static av_unused int pthread_once(pthread_once_t *once_control, void (*init_routine)(void)) -{ - w32thread_once_fallback(&w32thread_init_state, w32thread_init); - - /* Use native functions on Windows 6.0+ */ - if (initonce_begin && initonce_complete) { - BOOL pending = FALSE; - initonce_begin(once_control, 0, &pending, NULL); - if (pending) - init_routine(); - initonce_complete(once_control, 0, NULL); - return 0; - } - - w32thread_once_fallback(&once_control->state, init_routine); - return 0; -} - -/* for pre-Windows 6.0 platforms we need to define and use our own condition - * variable and api */ - -typedef struct win32_cond_t { - pthread_mutex_t mtx_broadcast; - pthread_mutex_t mtx_waiter_count; - volatile int waiter_count; - HANDLE semaphore; - HANDLE waiters_done; - volatile int is_broadcast; -} win32_cond_t; - -/* function pointers to conditional variable API on windows 6.0+ kernels */ -static void (WINAPI *cond_broadcast)(pthread_cond_t *cond); -static void (WINAPI *cond_init)(pthread_cond_t *cond); -static void (WINAPI *cond_signal)(pthread_cond_t *cond); -static BOOL (WINAPI *cond_wait)(pthread_cond_t *cond, pthread_mutex_t *mutex, - DWORD milliseconds); - -static av_unused int pthread_cond_init(pthread_cond_t *cond, const void *unused_attr) -{ - win32_cond_t *win32_cond = NULL; - - w32thread_once_fallback(&w32thread_init_state, w32thread_init); - - if (cond_init) { - cond_init(cond); - return 0; - } - - /* non native condition variables */ - win32_cond = (win32_cond_t*)av_mallocz(sizeof(win32_cond_t)); - if (!win32_cond) - return ENOMEM; - cond->Ptr = win32_cond; - win32_cond->semaphore = CreateSemaphore(NULL, 0, 0x7fffffff, NULL); - if (!win32_cond->semaphore) - return ENOMEM; - win32_cond->waiters_done = CreateEvent(NULL, TRUE, FALSE, NULL); - if (!win32_cond->waiters_done) - return ENOMEM; - - pthread_mutex_init(&win32_cond->mtx_waiter_count, NULL); - pthread_mutex_init(&win32_cond->mtx_broadcast, NULL); - return 0; -} - -static av_unused int pthread_cond_destroy(pthread_cond_t *cond) -{ - win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr; - /* native condition variables do not destroy */ - if (cond_init) - return 0; - - /* non native condition variables */ - CloseHandle(win32_cond->semaphore); - CloseHandle(win32_cond->waiters_done); - pthread_mutex_destroy(&win32_cond->mtx_waiter_count); - pthread_mutex_destroy(&win32_cond->mtx_broadcast); - av_freep(&win32_cond); - cond->Ptr = NULL; - return 0; -} - -static av_unused int pthread_cond_broadcast(pthread_cond_t *cond) -{ - win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr; - int have_waiter; - - if (cond_broadcast) { - cond_broadcast(cond); - return 0; - } - - /* non native condition variables */ - pthread_mutex_lock(&win32_cond->mtx_broadcast); - pthread_mutex_lock(&win32_cond->mtx_waiter_count); - have_waiter = 0; - - if (win32_cond->waiter_count) { - win32_cond->is_broadcast = 1; - have_waiter = 1; - } - - if (have_waiter) { - ReleaseSemaphore(win32_cond->semaphore, win32_cond->waiter_count, NULL); - pthread_mutex_unlock(&win32_cond->mtx_waiter_count); - WaitForSingleObject(win32_cond->waiters_done, INFINITE); - ResetEvent(win32_cond->waiters_done); - win32_cond->is_broadcast = 0; - } else - pthread_mutex_unlock(&win32_cond->mtx_waiter_count); - pthread_mutex_unlock(&win32_cond->mtx_broadcast); - return 0; -} - -static av_unused int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex) -{ - win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr; - int last_waiter; - if (cond_wait) { - cond_wait(cond, mutex, INFINITE); - return 0; - } - - /* non native condition variables */ - pthread_mutex_lock(&win32_cond->mtx_broadcast); - pthread_mutex_lock(&win32_cond->mtx_waiter_count); - win32_cond->waiter_count++; - pthread_mutex_unlock(&win32_cond->mtx_waiter_count); - pthread_mutex_unlock(&win32_cond->mtx_broadcast); - - // unlock the external mutex - pthread_mutex_unlock(mutex); - WaitForSingleObject(win32_cond->semaphore, INFINITE); - - pthread_mutex_lock(&win32_cond->mtx_waiter_count); - win32_cond->waiter_count--; - last_waiter = !win32_cond->waiter_count || !win32_cond->is_broadcast; - pthread_mutex_unlock(&win32_cond->mtx_waiter_count); - - if (last_waiter) - SetEvent(win32_cond->waiters_done); - - // lock the external mutex - return pthread_mutex_lock(mutex); -} - -static av_unused int pthread_cond_signal(pthread_cond_t *cond) -{ - win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr; - int have_waiter; - if (cond_signal) { - cond_signal(cond); - return 0; - } - - pthread_mutex_lock(&win32_cond->mtx_broadcast); - - /* non-native condition variables */ - pthread_mutex_lock(&win32_cond->mtx_waiter_count); - have_waiter = win32_cond->waiter_count; - pthread_mutex_unlock(&win32_cond->mtx_waiter_count); - - if (have_waiter) { - ReleaseSemaphore(win32_cond->semaphore, 1, NULL); - WaitForSingleObject(win32_cond->waiters_done, INFINITE); - ResetEvent(win32_cond->waiters_done); - } - - pthread_mutex_unlock(&win32_cond->mtx_broadcast); - return 0; -} -#endif - -static av_unused void w32thread_init(void) -{ -#if _WIN32_WINNT < 0x0600 - HMODULE kernel_dll = GetModuleHandle(TEXT("kernel32.dll")); - /* if one is available, then they should all be available */ - cond_init = (void (WINAPI*)(pthread_cond_t *)) - GetProcAddress(kernel_dll, "InitializeConditionVariable"); - cond_broadcast = (void (WINAPI*)(pthread_cond_t *)) - GetProcAddress(kernel_dll, "WakeAllConditionVariable"); - cond_signal = (void (WINAPI*)(pthread_cond_t *)) - GetProcAddress(kernel_dll, "WakeConditionVariable"); - cond_wait = (BOOL (WINAPI*)(pthread_cond_t *, pthread_mutex_t *, DWORD)) - GetProcAddress(kernel_dll, "SleepConditionVariableCS"); - initonce_begin = (BOOL (WINAPI*)(pthread_once_t *, DWORD, BOOL *, void **)) - GetProcAddress(kernel_dll, "InitOnceBeginInitialize"); - initonce_complete = (BOOL (WINAPI*)(pthread_once_t *, DWORD, void *)) - GetProcAddress(kernel_dll, "InitOnceComplete"); -#endif - -} - #endif /* COMPAT_W32PTHREADS_H */ |