[vlc-commits] thread: use generic semaphores on all platforms

Rémi Denis-Courmont git at videolan.org
Mon Feb 17 17:54:59 CET 2020


vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Sun Feb 16 19:04:50 2020 +0200| [cf1e3e99d328c844895ccae9271bdaf3548fb1fd] | committer: Rémi Denis-Courmont

thread: use generic semaphores on all platforms

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=cf1e3e99d328c844895ccae9271bdaf3548fb1fd
---

 include/vlc_threads.h | 14 --------------
 src/darwin/thread.c   | 45 ---------------------------------------------
 src/misc/threads.c    |  3 ---
 src/posix/thread.c    | 44 --------------------------------------------
 src/win32/thread.c    | 51 ---------------------------------------------------
 5 files changed, 157 deletions(-)

diff --git a/include/vlc_threads.h b/include/vlc_threads.h
index 688855ca72..584b6416b1 100644
--- a/include/vlc_threads.h
+++ b/include/vlc_threads.h
@@ -70,7 +70,6 @@ typedef struct
 } vlc_mutex_t;
 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
 #define LIBVLC_NEED_CONDVAR
-#define LIBVLC_NEED_SEMAPHORE
 #define LIBVLC_NEED_RWLOCK
 typedef INIT_ONCE vlc_once_t;
 #define VLC_STATIC_ONCE INIT_ONCE_STATIC_INIT
@@ -123,7 +122,6 @@ typedef struct
     unsigned signaled;
 } vlc_cond_t;
 #define VLC_STATIC_COND { NULLHANDLE, 0, NULLHANDLE, 0 }
-#define LIBVLC_NEED_SEMAPHORE
 #define LIBVLC_NEED_RWLOCK
 typedef struct
 {
@@ -172,7 +170,6 @@ static inline int vlc_poll (struct pollfd *fds, unsigned nfds, int timeout)
 # define LIBVLC_USE_PTHREAD_CLEANUP   1
 # define LIBVLC_NEED_SLEEP
 # define LIBVLC_NEED_CONDVAR
-# define LIBVLC_NEED_SEMAPHORE
 # define LIBVLC_NEED_RWLOCK
 
 typedef struct vlc_thread *vlc_thread_t;
@@ -226,7 +223,6 @@ typedef pthread_mutex_t vlc_mutex_t;
 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
 typedef pthread_cond_t vlc_cond_t;
 #define VLC_STATIC_COND PTHREAD_COND_INITIALIZER
-typedef semaphore_t     vlc_sem_t;
 typedef pthread_rwlock_t vlc_rwlock_t;
 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
 typedef pthread_once_t  vlc_once_t;
@@ -244,7 +240,6 @@ typedef struct vlc_timer *vlc_timer_t;
 #else /* POSIX threads */
 # include <unistd.h> /* _POSIX_SPIN_LOCKS */
 # include <pthread.h>
-# include <semaphore.h>
 
 /**
  * Whether LibVLC threads are based on POSIX threads.
@@ -299,13 +294,6 @@ typedef pthread_cond_t  vlc_cond_t;
  */
 #define VLC_STATIC_COND  PTHREAD_COND_INITIALIZER
 
-/**
- * Semaphore.
- *
- * Storage space for a thread-safe semaphore.
- */
-typedef sem_t           vlc_sem_t;
-
 /**
  * Read/write lock.
  *
@@ -367,7 +355,6 @@ typedef struct
 # define VLC_STATIC_COND { 0 }
 #endif
 
-#ifdef LIBVLC_NEED_SEMAPHORE
 typedef struct vlc_sem
 {
     union {
@@ -377,7 +364,6 @@ typedef struct vlc_sem
         int dummy;
    };
 } vlc_sem_t;
-#endif
 
 #ifdef LIBVLC_NEED_RWLOCK
 typedef struct vlc_rwlock
diff --git a/src/darwin/thread.c b/src/darwin/thread.c
index 1eca7755d2..349a4935f3 100644
--- a/src/darwin/thread.c
+++ b/src/darwin/thread.c
@@ -312,51 +312,6 @@ int vlc_cond_timedwait_daytime (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
 }
 
 
-/* Initialize a semaphore. */
-void vlc_sem_init (vlc_sem_t *sem, unsigned value)
-{
-    if (unlikely(semaphore_create(mach_task_self(), sem, SYNC_POLICY_FIFO, value) != KERN_SUCCESS))
-        abort ();
-}
-
-void vlc_sem_destroy (vlc_sem_t *sem)
-{
-    int val;
-
-    if (likely(semaphore_destroy(mach_task_self(), *sem) == KERN_SUCCESS))
-        return;
-
-    val = EINVAL;
-
-    VLC_THREAD_ASSERT ("destroying semaphore");
-}
-
-int vlc_sem_post (vlc_sem_t *sem)
-{
-    int val;
-
-    if (likely(semaphore_signal(*sem) == KERN_SUCCESS))
-        return 0;
-
-    val = EINVAL;
-
-    if (unlikely(val != EOVERFLOW))
-        VLC_THREAD_ASSERT ("unlocking semaphore");
-    return val;
-}
-
-void vlc_sem_wait (vlc_sem_t *sem)
-{
-    int val;
-
-    if (likely(semaphore_wait(*sem) == KERN_SUCCESS))
-        return;
-
-    val = EINVAL;
-
-    VLC_THREAD_ASSERT ("locking semaphore");
-}
-
 void vlc_rwlock_init (vlc_rwlock_t *lock)
 {
     if (unlikely(pthread_rwlock_init (lock, NULL)))
diff --git a/src/misc/threads.c b/src/misc/threads.c
index 8f365efad8..edd10bf7b4 100644
--- a/src/misc/threads.c
+++ b/src/misc/threads.c
@@ -153,7 +153,6 @@ bool vlc_mutex_marked(const vlc_mutex_t *mutex)
 #if defined (_WIN32) && (_WIN32_WINNT < _WIN32_WINNT_WIN8)
 /* Cannot define OS version-dependent stuff in public headers */
 # undef LIBVLC_NEED_SLEEP
-# undef LIBVLC_NEED_SEMAPHORE
 #endif
 
 #if defined(LIBVLC_NEED_SLEEP) || defined(LIBVLC_NEED_CONDVAR)
@@ -397,7 +396,6 @@ void vlc_rwlock_unlock (vlc_rwlock_t *lock)
 }
 #endif /* LIBVLC_NEED_RWLOCK */
 
-#ifdef LIBVLC_NEED_SEMAPHORE
 /*** Generic semaphores ***/
 
 void vlc_sem_init (vlc_sem_t *sem, unsigned value)
@@ -441,4 +439,3 @@ void vlc_sem_wait (vlc_sem_t *sem)
         }
     }
 }
-#endif /* LIBVLC_NEED_SEMAPHORE */
diff --git a/src/posix/thread.c b/src/posix/thread.c
index dfe0ea7c9d..9c9271a100 100644
--- a/src/posix/thread.c
+++ b/src/posix/thread.c
@@ -226,50 +226,6 @@ int vlc_cond_timedwait_daytime (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
     return val;
 }
 
-void vlc_sem_init (vlc_sem_t *sem, unsigned value)
-{
-    if (unlikely(sem_init (sem, 0, value)))
-        abort ();
-}
-
-void vlc_sem_destroy (vlc_sem_t *sem)
-{
-    int val;
-
-    if (likely(sem_destroy (sem) == 0))
-        return;
-
-    val = errno;
-
-    VLC_THREAD_ASSERT ("destroying semaphore");
-}
-
-int vlc_sem_post (vlc_sem_t *sem)
-{
-    int val;
-
-    if (likely(sem_post (sem) == 0))
-        return 0;
-
-    val = errno;
-
-    if (unlikely(val != EOVERFLOW))
-        VLC_THREAD_ASSERT ("unlocking semaphore");
-    return val;
-}
-
-void vlc_sem_wait (vlc_sem_t *sem)
-{
-    int val;
-
-    do
-        if (likely(sem_wait (sem) == 0))
-            return;
-    while ((val = errno) == EINTR);
-
-    VLC_THREAD_ASSERT ("locking semaphore");
-}
-
 void vlc_rwlock_init (vlc_rwlock_t *lock)
 {
     if (unlikely(pthread_rwlock_init (lock, NULL)))
diff --git a/src/win32/thread.c b/src/win32/thread.c
index 7bc6196519..4d6d7bdb5d 100644
--- a/src/win32/thread.c
+++ b/src/win32/thread.c
@@ -154,57 +154,6 @@ void vlc_mutex_unlock (vlc_mutex_t *p_mutex)
     vlc_mutex_unmark(p_mutex);
 }
 
-/*** Semaphore ***/
-#if (_WIN32_WINNT < _WIN32_WINNT_WIN8)
-# include <stdalign.h>
-
-static inline HANDLE *vlc_sem_handle_p(vlc_sem_t *sem)
-{
-    /* NOTE: vlc_sem_t layout cannot easily depend on Windows version */
-    static_assert (sizeof (HANDLE) <= sizeof (vlc_sem_t), "Size mismatch!");
-    static_assert ((alignof (HANDLE) % alignof (vlc_sem_t)) == 0,
-                   "Alignment mismatch");
-    return (HANDLE *)sem;
-}
-#define vlc_sem_handle(sem) (*vlc_sem_handle_p(sem))
-
-void vlc_sem_init (vlc_sem_t *sem, unsigned value)
-{
-    HANDLE handle = CreateSemaphore(NULL, value, 0x7fffffff, NULL);
-    if (handle == NULL)
-        abort ();
-
-    vlc_sem_handle(sem) = handle;
-}
-
-void vlc_sem_destroy (vlc_sem_t *sem)
-{
-    CloseHandle(vlc_sem_handle(sem));
-}
-
-int vlc_sem_post (vlc_sem_t *sem)
-{
-    ReleaseSemaphore(vlc_sem_handle(sem), 1, NULL);
-    return 0; /* FIXME */
-}
-
-void vlc_sem_wait (vlc_sem_t *sem)
-{
-    HANDLE handle = vlc_sem_handle(sem);
-    DWORD result;
-
-    do
-    {
-        vlc_testcancel ();
-        result = WaitForSingleObjectEx(handle, INFINITE, TRUE);
-
-        /* Semaphore abandoned would be a bug. */
-        assert(result != WAIT_ABANDONED_0);
-    }
-    while (result == WAIT_IO_COMPLETION || result == WAIT_FAILED);
-}
-#endif
-
 /*** One-time initialization ***/
 static BOOL CALLBACK vlc_once_callback(INIT_ONCE *once, void *parm, void **ctx)
 {



More information about the vlc-commits mailing list