w32pthreads: always use Vista+ API, drop XP support
[libav.git] / compat / w32pthreads.h
dissimilarity index 67%
index f38f767..c569983 100644 (file)
-/*
- * Copyright (C) 2010-2011 x264 project
- *
- * Authors: Steven Walters <kemuri9@gmail.com>
- *          Pegasys Inc. <http://www.pegasys-inc.com>
- *
- * This file is part of Libav.
- *
- * Libav is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * Libav is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-/**
- * @file
- * w32threads to pthreads wrapper
- */
-
-#ifndef LIBAV_COMPAT_W32PTHREADS_H
-#define LIBAV_COMPAT_W32PTHREADS_H
-
-/* Build up a pthread-like API using underlying Windows API. Have only static
- * methods so as to not conflict with a potentially linked in pthread-win32
- * library.
- * As most functions here are used without checking return values,
- * only implement return values as necessary. */
-
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <process.h>
-
-#if _WIN32_WINNT < 0x0600 && defined(__MINGW32__)
-#undef MemoryBarrier
-#define MemoryBarrier __sync_synchronize
-#endif
-
-#include "libavutil/attributes.h"
-#include "libavutil/internal.h"
-#include "libavutil/mem.h"
-
-typedef struct pthread_t {
-    void *handle;
-    void *(*func)(void* arg);
-    void *arg;
-    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
-typedef CONDITION_VARIABLE pthread_cond_t;
-#else
-typedef struct pthread_cond_t {
-    void *Ptr;
-} pthread_cond_t;
-#endif
-
-#if _WIN32_WINNT >= 0x0600
-#define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0)
-#define WaitForSingleObject(a, b) WaitForSingleObjectEx(a, b, FALSE)
-#endif
-
-static av_unused unsigned __stdcall attribute_align_arg win32thread_worker(void *arg)
-{
-    pthread_t *h = arg;
-    h->ret = h->func(h->arg);
-    return 0;
-}
-
-static av_unused int pthread_create(pthread_t *thread, const void *unused_attr,
-                                    void *(*start_routine)(void*), void *arg)
-{
-    thread->func   = start_routine;
-    thread->arg    = arg;
-    thread->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, thread,
-                                           0, NULL);
-    return !thread->handle;
-}
-
-static av_unused void pthread_join(pthread_t thread, void **value_ptr)
-{
-    DWORD ret = WaitForSingleObject(thread.handle, INFINITE);
-    if (ret != WAIT_OBJECT_0)
-        return;
-    if (value_ptr)
-        *value_ptr = thread.ret;
-    CloseHandle(thread.handle);
-}
-
-static inline int pthread_mutex_init(pthread_mutex_t *m, void* attr)
-{
-    InitializeCriticalSection(m);
-    return 0;
-}
-static inline int pthread_mutex_destroy(pthread_mutex_t *m)
-{
-    DeleteCriticalSection(m);
-    return 0;
-}
-static inline int pthread_mutex_lock(pthread_mutex_t *m)
-{
-    EnterCriticalSection(m);
-    return 0;
-}
-static inline int pthread_mutex_unlock(pthread_mutex_t *m)
-{
-    LeaveCriticalSection(m);
-    return 0;
-}
-
-#if _WIN32_WINNT >= 0x0600
-
-typedef INIT_ONCE pthread_once_t;
-#define PTHREAD_ONCE_INIT INIT_ONCE_STATIC_INIT
-
-static av_unused int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
-{
-    BOOL pending = FALSE;
-    InitOnceBeginInitialize(once_control, 0, &pending, NULL);
-    if (pending)
-        init_routine();
-    InitOnceComplete(once_control, 0, NULL);
-    return 0;
-}
-
-static inline void pthread_cond_init(pthread_cond_t *cond, const void *unused_attr)
-{
-    InitializeConditionVariable(cond);
-}
-
-/* native condition variables do not destroy */
-static inline void pthread_cond_destroy(pthread_cond_t *cond)
-{
-    return;
-}
-
-static inline void pthread_cond_broadcast(pthread_cond_t *cond)
-{
-    WakeAllConditionVariable(cond);
-}
-
-static inline int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
-{
-    SleepConditionVariableCS(cond, mutex, INFINITE);
-    return 0;
-}
-
-static inline void pthread_cond_signal(pthread_cond_t *cond)
-{
-    WakeConditionVariable(cond);
-}
-
-#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 void 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;
-    }
-
-    /* non native condition variables */
-    win32_cond = av_mallocz(sizeof(win32_cond_t));
-    if (!win32_cond)
-        return;
-    cond->Ptr = win32_cond;
-    win32_cond->semaphore = CreateSemaphore(NULL, 0, 0x7fffffff, NULL);
-    if (!win32_cond->semaphore)
-        return;
-    win32_cond->waiters_done = CreateEvent(NULL, TRUE, FALSE, NULL);
-    if (!win32_cond->waiters_done)
-        return;
-
-    pthread_mutex_init(&win32_cond->mtx_waiter_count, NULL);
-    pthread_mutex_init(&win32_cond->mtx_broadcast, NULL);
-}
-
-static av_unused void pthread_cond_destroy(pthread_cond_t *cond)
-{
-    win32_cond_t *win32_cond = cond->Ptr;
-    /* native condition variables do not destroy */
-    if (cond_init)
-        return;
-
-    /* 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;
-}
-
-static av_unused void pthread_cond_broadcast(pthread_cond_t *cond)
-{
-    win32_cond_t *win32_cond = cond->Ptr;
-    int have_waiter;
-
-    if (cond_broadcast) {
-        cond_broadcast(cond);
-        return;
-    }
-
-    /* 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);
-}
-
-static av_unused int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
-{
-    win32_cond_t *win32_cond = 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 void pthread_cond_signal(pthread_cond_t *cond)
-{
-    win32_cond_t *win32_cond = cond->Ptr;
-    int have_waiter;
-    if (cond_signal) {
-        cond_signal(cond);
-        return;
-    }
-
-    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);
-}
-#endif
-
-static av_unused void w32thread_init(void)
-{
-#if _WIN32_WINNT < 0x0600
-    HANDLE 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 /* LIBAV_COMPAT_W32PTHREADS_H */
+/*
+ * Copyright (C) 2010-2011 x264 project
+ *
+ * Authors: Steven Walters <kemuri9@gmail.com>
+ *          Pegasys Inc. <http://www.pegasys-inc.com>
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * w32threads to pthreads wrapper
+ */
+
+#ifndef LIBAV_COMPAT_W32PTHREADS_H
+#define LIBAV_COMPAT_W32PTHREADS_H
+
+/* Build up a pthread-like API using underlying Windows API. Have only static
+ * methods so as to not conflict with a potentially linked in pthread-win32
+ * library.
+ * As most functions here are used without checking return values,
+ * only implement return values as necessary. */
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <process.h>
+
+#include "libavutil/attributes.h"
+#include "libavutil/internal.h"
+#include "libavutil/mem.h"
+
+typedef struct pthread_t {
+    void *handle;
+    void *(*func)(void* arg);
+    void *arg;
+    void *ret;
+} pthread_t;
+
+/* use lightweight mutex/condition variable API for Windows Vista and later */
+typedef SRWLOCK pthread_mutex_t;
+typedef CONDITION_VARIABLE pthread_cond_t;
+
+#define PTHREAD_MUTEX_INITIALIZER SRWLOCK_INIT
+#define PTHREAD_COND_INITIALIZER CONDITION_VARIABLE_INIT
+
+#define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0)
+#define WaitForSingleObject(a, b) WaitForSingleObjectEx(a, b, FALSE)
+
+static av_unused unsigned __stdcall attribute_align_arg win32thread_worker(void *arg)
+{
+    pthread_t *h = arg;
+    h->ret = h->func(h->arg);
+    return 0;
+}
+
+static av_unused int pthread_create(pthread_t *thread, const void *unused_attr,
+                                    void *(*start_routine)(void*), void *arg)
+{
+    thread->func   = start_routine;
+    thread->arg    = arg;
+    thread->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, thread,
+                                           0, NULL);
+    return !thread->handle;
+}
+
+static av_unused void pthread_join(pthread_t thread, void **value_ptr)
+{
+    DWORD ret = WaitForSingleObject(thread.handle, INFINITE);
+    if (ret != WAIT_OBJECT_0)
+        return;
+    if (value_ptr)
+        *value_ptr = thread.ret;
+    CloseHandle(thread.handle);
+}
+
+static inline int pthread_mutex_init(pthread_mutex_t *m, void* attr)
+{
+    InitializeSRWLock(m);
+    return 0;
+}
+static inline int pthread_mutex_destroy(pthread_mutex_t *m)
+{
+    /* Unlocked SWR locks use no resources */
+    return 0;
+}
+static inline int pthread_mutex_lock(pthread_mutex_t *m)
+{
+    AcquireSRWLockExclusive(m);
+    return 0;
+}
+static inline int pthread_mutex_unlock(pthread_mutex_t *m)
+{
+    ReleaseSRWLockExclusive(m);
+    return 0;
+}
+
+
+typedef INIT_ONCE pthread_once_t;
+#define PTHREAD_ONCE_INIT INIT_ONCE_STATIC_INIT
+
+static av_unused int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
+{
+    BOOL pending = FALSE;
+    InitOnceBeginInitialize(once_control, 0, &pending, NULL);
+    if (pending)
+        init_routine();
+    InitOnceComplete(once_control, 0, NULL);
+    return 0;
+}
+
+static inline void pthread_cond_init(pthread_cond_t *cond, const void *unused_attr)
+{
+    InitializeConditionVariable(cond);
+}
+
+/* native condition variables do not destroy */
+static inline void pthread_cond_destroy(pthread_cond_t *cond)
+{
+    return;
+}
+
+static inline void pthread_cond_broadcast(pthread_cond_t *cond)
+{
+    WakeAllConditionVariable(cond);
+}
+
+static inline int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
+{
+    SleepConditionVariableSRW(cond, mutex, INFINITE, 0);
+    return 0;
+}
+
+static inline void pthread_cond_signal(pthread_cond_t *cond)
+{
+    WakeConditionVariable(cond);
+}
+
+#endif /* LIBAV_COMPAT_W32PTHREADS_H */