* Samuel Hocevar <sam@zoy.org>
* Gildas Bazin <gbazin@netcourrier.com>
* Clément Sténac
+ * Rémi Denis-Courmont
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#endif
#include <signal.h>
-#define VLC_THREADS_UNINITIALIZED 0
-#define VLC_THREADS_PENDING 1
-#define VLC_THREADS_ERROR 2
-#define VLC_THREADS_READY 3
-
-/*****************************************************************************
- * Global mutex for lazy initialization of the threads system
- *****************************************************************************/
-static volatile unsigned i_initializations = 0;
-
#if defined( LIBVLC_USE_PTHREAD )
# include <sched.h>
-
-static pthread_mutex_t once_mutex = PTHREAD_MUTEX_INITIALIZER;
+# ifdef __linux__
+# include <sys/syscall.h> /* SYS_gettid */
+# endif
#else
static vlc_threadvar_t cancel_key;
#endif
-/**
- * Global process-wide VLC object.
- * Contains inter-instance data, such as the module cache and global mutexes.
- */
-static libvlc_global_data_t *p_root;
-
-libvlc_global_data_t *vlc_global( void )
-{
- assert( i_initializations > 0 );
- return p_root;
-}
-
#ifdef HAVE_EXECINFO_H
# include <execinfo.h>
#endif
+#ifdef __APPLE__
+# include <sys/time.h> /* gettimeofday in vlc_cond_timedwait */
+#endif
+
/**
* Print a backtrace to the standard error for debugging purpose.
*/
static inline unsigned long vlc_threadid (void)
{
-#if defined(LIBVLC_USE_PTHREAD)
+#if defined (LIBVLC_USE_PTHREAD)
+# if defined (__linux__)
+ return syscall (SYS_gettid);
+
+# else
union { pthread_t th; unsigned long int i; } v = { };
v.th = pthread_self ();
return v.i;
+#endif
#elif defined (WIN32)
return GetCurrentThreadId ();
#endif
}
+#ifndef NDEBUG
/*****************************************************************************
* vlc_thread_fatal: Report an error from the threading layer
*****************************************************************************
* This is mostly meant for debugging.
*****************************************************************************/
-void vlc_thread_fatal (const char *action, int error, const char *function,
- const char *file, unsigned line)
+static void
+vlc_thread_fatal (const char *action, int error,
+ const char *function, const char *file, unsigned line)
{
fprintf (stderr, "LibVLC fatal error %s (%d) in thread %lu ",
action, error, vlc_threadid ());
#ifdef __GLIBC__
/* Avoid the strerror_r() prototype brain damage in glibc */
errno = error;
- fprintf (stderr, " Error message: %m at:\n");
-#else
+ fprintf (stderr, " Error message: %m\n");
+#elif !defined (WIN32)
char buf[1000];
const char *msg;
abort ();
}
+# define VLC_THREAD_ASSERT( action ) \
+ if (val) vlc_thread_fatal (action, val, __func__, __FILE__, __LINE__)
+#else
+# define VLC_THREAD_ASSERT( action ) ((void)val)
+#endif
+
/**
* Per-thread cancellation data
*/
vlc_cleanup_t *cleaners;
bool killable;
bool killed;
+# ifdef UNDER_CE
+ HANDLE cancel_event;
+# endif
} vlc_cancel_t;
-# define VLC_CANCEL_INIT { NULL, false, true }
+# ifndef UNDER_CE
+# define VLC_CANCEL_INIT { NULL, true, false }
+# else
+# define VLC_CANCEL_INIT { NULL, true, false, NULL }
+# endif
#endif
-/*****************************************************************************
- * vlc_threads_init: initialize threads system
- *****************************************************************************
- * This function requires lazy initialization of a global lock in order to
- * keep the library really thread-safe. Some architectures don't support this
- * and thus do not guarantee the complete reentrancy.
- *****************************************************************************/
-int vlc_threads_init( void )
-{
- int i_ret = VLC_SUCCESS;
+#ifdef UNDER_CE
+static void CALLBACK vlc_cancel_self (ULONG_PTR dummy);
- /* If we have lazy mutex initialization, use it. Otherwise, we just
- * hope nothing wrong happens. */
-#if defined( LIBVLC_USE_PTHREAD )
- pthread_mutex_lock( &once_mutex );
-#endif
-
- if( i_initializations == 0 )
+static DWORD vlc_cancelable_wait (DWORD count, const HANDLE *handles,
+ DWORD delay)
+{
+ vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
+ if (nfo == NULL)
{
- p_root = vlc_custom_create( (vlc_object_t *)NULL, sizeof( *p_root ),
- VLC_OBJECT_GENERIC, "root" );
- if( p_root == NULL )
- {
- i_ret = VLC_ENOMEM;
- goto out;
- }
+ /* Main thread - cannot be cancelled anyway */
+ return WaitForMultipleObjects (count, handles, FALSE, delay);
+ }
+ HANDLE new_handles[count + 1];
+ memcpy(new_handles, handles, count * sizeof(HANDLE));
+ new_handles[count] = nfo->cancel_event;
+ DWORD result = WaitForMultipleObjects (count + 1, new_handles, FALSE,
+ delay);
+ if (result == WAIT_OBJECT_0 + count)
+ {
+ vlc_cancel_self (NULL);
+ return WAIT_IO_COMPLETION;
+ }
+ else
+ {
+ return result;
+ }
+}
- /* We should be safe now. Do all the initialization stuff we want. */
-#ifndef LIBVLC_USE_PTHREAD_CANCEL
- vlc_threadvar_create( &cancel_key, free );
-#endif
+DWORD SleepEx (DWORD dwMilliseconds, BOOL bAlertable)
+{
+ if (bAlertable)
+ {
+ DWORD result = vlc_cancelable_wait (0, NULL, dwMilliseconds);
+ return (result == WAIT_TIMEOUT) ? 0 : WAIT_IO_COMPLETION;
}
- i_initializations++;
+ else
+ {
+ Sleep(dwMilliseconds);
+ return 0;
+ }
+}
-out:
- /* If we have lazy mutex initialization support, unlock the mutex.
- * Otherwize, we are screwed. */
-#if defined( LIBVLC_USE_PTHREAD )
- pthread_mutex_unlock( &once_mutex );
+DWORD WaitForSingleObjectEx (HANDLE hHandle, DWORD dwMilliseconds,
+ BOOL bAlertable)
+{
+ if (bAlertable)
+ {
+ /* The MSDN documentation specifies different return codes,
+ * but in practice they are the same. We just check that it
+ * remains so. */
+#if WAIT_ABANDONED != WAIT_ABANDONED_0
+# error Windows headers changed, code needs to be rewritten!
#endif
-
- return i_ret;
+ return vlc_cancelable_wait (1, &hHandle, dwMilliseconds);
+ }
+ else
+ {
+ return WaitForSingleObject (hHandle, dwMilliseconds);
+ }
}
-/*****************************************************************************
- * vlc_threads_end: stop threads system
- *****************************************************************************
- * FIXME: This function is far from being threadsafe.
- *****************************************************************************/
-void vlc_threads_end( void )
+DWORD WaitForMultipleObjectsEx (DWORD nCount, const HANDLE *lpHandles,
+ BOOL bWaitAll, DWORD dwMilliseconds,
+ BOOL bAlertable)
{
-#if defined( LIBVLC_USE_PTHREAD )
- pthread_mutex_lock( &once_mutex );
+ if (bAlertable)
+ {
+ /* We do not support the bWaitAll case */
+ assert (! bWaitAll);
+ return vlc_cancelable_wait (nCount, lpHandles, dwMilliseconds);
+ }
+ else
+ {
+ return WaitForMultipleObjects (nCount, lpHandles, bWaitAll,
+ dwMilliseconds);
+ }
+}
#endif
- assert( i_initializations > 0 );
+#ifdef WIN32
+static vlc_mutex_t super_mutex;
+
+BOOL WINAPI DllMain (HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved)
+{
+ (void) hinstDll;
+ (void) lpvReserved;
- if( i_initializations == 1 )
+ switch (fdwReason)
{
- vlc_object_release( p_root );
-#ifndef LIBVLC_USE_PTHREAD
- vlc_threadvar_delete( &cancel_key );
-#endif
- }
- i_initializations--;
+ case DLL_PROCESS_ATTACH:
+ vlc_mutex_init (&super_mutex);
+ vlc_threadvar_create (&cancel_key, free);
+ break;
-#if defined( LIBVLC_USE_PTHREAD )
- pthread_mutex_unlock( &once_mutex );
-#endif
+ case DLL_PROCESS_DETACH:
+ vlc_threadvar_delete( &cancel_key );
+ vlc_mutex_destroy (&super_mutex);
+ break;
+ }
+ return TRUE;
}
+#endif
#if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
/* This is not prototyped under glibc, though it exists. */
i_result = pthread_mutex_init( p_mutex, &attr );
pthread_mutexattr_destroy( &attr );
return i_result;
-#elif defined( UNDER_CE )
- InitializeCriticalSection( &p_mutex->csection );
- return 0;
#elif defined( WIN32 )
- *p_mutex = CreateMutex( 0, FALSE, 0 );
- return (*p_mutex != NULL) ? 0 : ENOMEM;
-
-#elif defined( HAVE_KERNEL_SCHEDULER_H )
- /* check the arguments and whether it's already been initialized */
- if( p_mutex == NULL )
- {
- return B_BAD_VALUE;
- }
-
- if( p_mutex->init == 9999 )
- {
- return EALREADY;
- }
-
- p_mutex->lock = create_sem( 1, "BeMutex" );
- if( p_mutex->lock < B_NO_ERROR )
- {
- return( -1 );
- }
-
- p_mutex->init = 9999;
- return B_OK;
+ /* This creates a recursive mutex. This is OK as fast mutexes have
+ * no defined behavior in case of recursive locking. */
+ InitializeCriticalSection (&p_mutex->mutex);
+ p_mutex->initialized = 1;
+ return 0;
#endif
}
i_result = pthread_mutex_init( p_mutex, &attr );
pthread_mutexattr_destroy( &attr );
return( i_result );
+
#elif defined( WIN32 )
- /* Create mutex returns a recursive mutex */
- *p_mutex = CreateMutex( 0, FALSE, 0 );
- return (*p_mutex != NULL) ? 0 : ENOMEM;
-#else
-# error Unimplemented!
+ InitializeCriticalSection( &p_mutex->mutex );
+ p_mutex->initialized = 1;
+ return 0;
+
#endif
}
-/*****************************************************************************
- * vlc_mutex_destroy: destroy a mutex, inner version
- *****************************************************************************/
-void __vlc_mutex_destroy( const char * psz_file, int i_line, vlc_mutex_t *p_mutex )
+/**
+ * Destroys a mutex. The mutex must not be locked.
+ *
+ * @param p_mutex mutex to destroy
+ * @return always succeeds
+ */
+void vlc_mutex_destroy (vlc_mutex_t *p_mutex)
{
#if defined( LIBVLC_USE_PTHREAD )
int val = pthread_mutex_destroy( p_mutex );
VLC_THREAD_ASSERT ("destroying mutex");
-#elif defined( UNDER_CE )
- VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
+#elif defined( WIN32 )
+ assert (InterlockedExchange (&p_mutex->initialized, -1) == 1);
+ DeleteCriticalSection (&p_mutex->mutex);
+
+#endif
+}
+
+#if defined(LIBVLC_USE_PTHREAD) && !defined(NDEBUG)
+# ifdef HAVE_VALGRIND_VALGRIND_H
+# include <valgrind/valgrind.h>
+# else
+# define RUNNING_ON_VALGRIND (0)
+# endif
+
+void vlc_assert_locked (vlc_mutex_t *p_mutex)
+{
+ if (RUNNING_ON_VALGRIND > 0)
+ return;
+ assert (pthread_mutex_lock (p_mutex) == EDEADLK);
+}
+#endif
- DeleteCriticalSection( &p_mutex->csection );
+/**
+ * Acquires a mutex. If needed, waits for any other thread to release it.
+ * Beware of deadlocks when locking multiple mutexes at the same time,
+ * or when using mutexes from callbacks.
+ * This function is not a cancellation-point.
+ *
+ * @param p_mutex mutex initialized with vlc_mutex_init() or
+ * vlc_mutex_init_recursive()
+ */
+void vlc_mutex_lock (vlc_mutex_t *p_mutex)
+{
+#if defined(LIBVLC_USE_PTHREAD)
+ int val = pthread_mutex_lock( p_mutex );
+ VLC_THREAD_ASSERT ("locking mutex");
#elif defined( WIN32 )
- VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
+ if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
+ { /* ^^ We could also lock super_mutex all the time... sluggish */
+ assert (p_mutex != &super_mutex); /* this one cannot be static */
+
+ vlc_mutex_lock (&super_mutex);
+ if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
+ vlc_mutex_init (p_mutex);
+ /* FIXME: destroy the mutex some time... */
+ vlc_mutex_unlock (&super_mutex);
+ }
+ assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
+ EnterCriticalSection (&p_mutex->mutex);
+
+#endif
+}
- CloseHandle( *p_mutex );
+/**
+ * Acquires a mutex if and only if it is not currently held by another thread.
+ * This function never sleeps and can be used in delay-critical code paths.
+ * This function is not a cancellation-point.
+ *
+ * <b>Beware</b>: If this function fails, then the mutex is held... by another
+ * thread. The calling thread must deal with the error appropriately. That
+ * typically implies postponing the operations that would have required the
+ * mutex. If the thread cannot defer those operations, then it must use
+ * vlc_mutex_lock(). If in doubt, use vlc_mutex_lock() instead.
+ *
+ * @param p_mutex mutex initialized with vlc_mutex_init() or
+ * vlc_mutex_init_recursive()
+ * @return 0 if the mutex could be acquired, an error code otherwise.
+ */
+int vlc_mutex_trylock (vlc_mutex_t *p_mutex)
+{
+#if defined(LIBVLC_USE_PTHREAD)
+ int val = pthread_mutex_trylock( p_mutex );
-#elif defined( HAVE_KERNEL_SCHEDULER_H )
- if( p_mutex->init == 9999 )
- delete_sem( p_mutex->lock );
+ if (val != EBUSY)
+ VLC_THREAD_ASSERT ("locking mutex");
+ return val;
- p_mutex->init = 0;
+#elif defined( WIN32 )
+ if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
+ { /* ^^ We could also lock super_mutex all the time... sluggish */
+ assert (p_mutex != &super_mutex); /* this one cannot be static */
+
+ vlc_mutex_lock (&super_mutex);
+ if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
+ vlc_mutex_init (p_mutex);
+ /* FIXME: destroy the mutex some time... */
+ vlc_mutex_unlock (&super_mutex);
+ }
+ assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
+ return TryEnterCriticalSection (&p_mutex->mutex) ? 0 : EBUSY;
+
+#endif
+}
+
+/**
+ * Releases a mutex (or crashes if the mutex is not locked by the caller).
+ * @param p_mutex mutex locked with vlc_mutex_lock().
+ */
+void vlc_mutex_unlock (vlc_mutex_t *p_mutex)
+{
+#if defined(LIBVLC_USE_PTHREAD)
+ int val = pthread_mutex_unlock( p_mutex );
+ VLC_THREAD_ASSERT ("unlocking mutex");
+
+#elif defined( WIN32 )
+ assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
+ LeaveCriticalSection (&p_mutex->mutex);
#endif
}
/*****************************************************************************
- * vlc_cond_init: initialize a condition
+ * vlc_cond_init: initialize a condition variable
*****************************************************************************/
-int __vlc_cond_init( vlc_cond_t *p_condvar )
+int vlc_cond_init( vlc_cond_t *p_condvar )
{
#if defined( LIBVLC_USE_PTHREAD )
pthread_condattr_t attr;
pthread_condattr_destroy (&attr);
return ret;
-#elif defined( UNDER_CE ) || defined( WIN32 )
- /* Create an auto-reset event. */
- *p_condvar = CreateEvent( NULL, /* no security */
- FALSE, /* auto-reset event */
- FALSE, /* start non-signaled */
- NULL ); /* unnamed */
+#elif defined( WIN32 )
+ /* Create a manual-reset event (manual reset is needed for broadcast). */
+ *p_condvar = CreateEvent( NULL, TRUE, FALSE, NULL );
return *p_condvar ? 0 : ENOMEM;
-#elif defined( HAVE_KERNEL_SCHEDULER_H )
- if( !p_condvar )
- {
- return B_BAD_VALUE;
- }
+#endif
+}
+
+/**
+ * Destroys a condition variable. No threads shall be waiting or signaling the
+ * condition.
+ * @param p_condvar condition variable to destroy
+ */
+void vlc_cond_destroy (vlc_cond_t *p_condvar)
+{
+#if defined( LIBVLC_USE_PTHREAD )
+ int val = pthread_cond_destroy( p_condvar );
+ VLC_THREAD_ASSERT ("destroying condition");
+
+#elif defined( WIN32 )
+ CloseHandle( *p_condvar );
+
+#endif
+}
- if( p_condvar->init == 9999 )
+/**
+ * Wakes up one thread waiting on a condition variable, if any.
+ * @param p_condvar condition variable
+ */
+void vlc_cond_signal (vlc_cond_t *p_condvar)
+{
+#if defined(LIBVLC_USE_PTHREAD)
+ int val = pthread_cond_signal( p_condvar );
+ VLC_THREAD_ASSERT ("signaling condition variable");
+
+#elif defined( WIN32 )
+ /* NOTE: This will cause a broadcast, that is wrong.
+ * This will also wake up the next waiting thread if no thread are yet
+ * waiting, which is also wrong. However both of these issues are allowed
+ * by the provision for spurious wakeups. Better have too many wakeups
+ * than too few (= deadlocks). */
+ SetEvent (*p_condvar);
+
+#endif
+}
+
+/**
+ * Wakes up all threads (if any) waiting on a condition variable.
+ * @param p_cond condition variable
+ */
+void vlc_cond_broadcast (vlc_cond_t *p_condvar)
+{
+#if defined (LIBVLC_USE_PTHREAD)
+ pthread_cond_broadcast (p_condvar);
+
+#elif defined (WIN32)
+ SetEvent (*p_condvar);
+
+#endif
+}
+
+/**
+ * Waits for a condition variable. The calling thread will be suspended until
+ * another thread calls vlc_cond_signal() or vlc_cond_broadcast() on the same
+ * condition variable, the thread is cancelled with vlc_cancel(), or the
+ * system causes a "spurious" unsolicited wake-up.
+ *
+ * A mutex is needed to wait on a condition variable. It must <b>not</b> be
+ * a recursive mutex. Although it is possible to use the same mutex for
+ * multiple condition, it is not valid to use different mutexes for the same
+ * condition variable at the same time from different threads.
+ *
+ * In case of thread cancellation, the mutex is always locked before
+ * cancellation proceeds.
+ *
+ * The canonical way to use a condition variable to wait for event foobar is:
+ @code
+ vlc_mutex_lock (&lock);
+ mutex_cleanup_push (&lock); // release the mutex in case of cancellation
+
+ while (!foobar)
+ vlc_cond_wait (&wait, &lock);
+
+ --- foobar is now true, do something about it here --
+
+ vlc_cleanup_run (); // release the mutex
+ @endcode
+ *
+ * @param p_condvar condition variable to wait on
+ * @param p_mutex mutex which is unlocked while waiting,
+ * then locked again when waking up.
+ * @param deadline <b>absolute</b> timeout
+ *
+ * @return 0 if the condition was signaled, an error code in case of timeout.
+ */
+void vlc_cond_wait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex)
+{
+#if defined(LIBVLC_USE_PTHREAD)
+ int val = pthread_cond_wait( p_condvar, p_mutex );
+ VLC_THREAD_ASSERT ("waiting on condition");
+
+#elif defined( WIN32 )
+ DWORD result;
+
+ do
{
- return EALREADY;
+ vlc_testcancel ();
+ LeaveCriticalSection (&p_mutex->mutex);
+ result = WaitForSingleObjectEx (*p_condvar, INFINITE, TRUE);
+ EnterCriticalSection (&p_mutex->mutex);
}
+ while (result == WAIT_IO_COMPLETION);
- p_condvar->thread = -1;
- p_condvar->init = 9999;
- return 0;
+ assert (result != WAIT_ABANDONED); /* another thread failed to cleanup! */
+ assert (result != WAIT_FAILED);
+ ResetEvent (*p_condvar);
#endif
}
-/*****************************************************************************
- * vlc_cond_destroy: destroy a condition, inner version
- *****************************************************************************/
-void __vlc_cond_destroy( const char * psz_file, int i_line, vlc_cond_t *p_condvar )
+/**
+ * Waits for a condition variable up to a certain date.
+ * This works like vlc_cond_wait(), except for the additional timeout.
+ *
+ * @param p_condvar condition variable to wait on
+ * @param p_mutex mutex which is unlocked while waiting,
+ * then locked again when waking up.
+ * @param deadline <b>absolute</b> timeout
+ *
+ * @return 0 if the condition was signaled, an error code in case of timeout.
+ */
+int vlc_cond_timedwait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
+ mtime_t deadline)
{
-#if defined( LIBVLC_USE_PTHREAD )
- int val = pthread_cond_destroy( p_condvar );
- VLC_THREAD_ASSERT ("destroying condition");
+#if defined(LIBVLC_USE_PTHREAD)
+#ifdef __APPLE__
+ /* mdate() is mac_absolute_time on osx, which we must convert to do
+ * the same base than gettimeofday() on which pthread_cond_timedwait
+ * counts on. */
+ mtime_t oldbase = mdate();
+ struct timeval tv;
+ gettimeofday(&tv, NULL);
+ mtime_t newbase = (mtime_t)tv.tv_sec * 1000000 + (mtime_t) tv.tv_usec;
+ deadline = deadline - oldbase + newbase;
+#endif
+ lldiv_t d = lldiv( deadline, CLOCK_FREQ );
+ struct timespec ts = { d.quot, d.rem * (1000000000 / CLOCK_FREQ) };
-#elif defined( UNDER_CE ) || defined( WIN32 )
- VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
+ int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
+ if (val != ETIMEDOUT)
+ VLC_THREAD_ASSERT ("timed-waiting on condition");
+ return val;
- CloseHandle( *p_condvar );
+#elif defined( WIN32 )
+ DWORD result;
-#elif defined( HAVE_KERNEL_SCHEDULER_H )
- p_condvar->init = 0;
+ do
+ {
+ vlc_testcancel ();
+
+ mtime_t total = (deadline - mdate ())/1000;
+ if( total < 0 )
+ total = 0;
+
+ DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
+ LeaveCriticalSection (&p_mutex->mutex);
+ result = WaitForSingleObjectEx (*p_condvar, delay, TRUE);
+ EnterCriticalSection (&p_mutex->mutex);
+ }
+ while (result == WAIT_IO_COMPLETION);
+
+ assert (result != WAIT_ABANDONED);
+ assert (result != WAIT_FAILED);
+ ResetEvent (*p_condvar);
+
+ return (result == WAIT_OBJECT_0) ? 0 : ETIMEDOUT;
#endif
}
#if defined( LIBVLC_USE_PTHREAD )
i_ret = pthread_key_create( p_tls, destr );
-#elif defined( UNDER_CE )
- i_ret = ENOSYS;
#elif defined( WIN32 )
/* FIXME: remember/use the destr() callback and stop leaking whatever */
*p_tls = TlsAlloc();
{
#if defined( LIBVLC_USE_PTHREAD )
pthread_key_delete (*p_tls);
-#elif defined( UNDER_CE )
#elif defined( WIN32 )
TlsFree (*p_tls);
#else
#endif
}
+/**
+ * Sets a thread-local variable.
+ * @param key thread-local variable key (created with vlc_threadvar_create())
+ * @param value new value for the variable for the calling thread
+ * @return 0 on success, a system error code otherwise.
+ */
+int vlc_threadvar_set (vlc_threadvar_t key, void *value)
+{
+#if defined(LIBVLC_USE_PTHREAD)
+ return pthread_setspecific (key, value);
+#elif defined( UNDER_CE ) || defined( WIN32 )
+ return TlsSetValue (key, value) ? ENOMEM : 0;
+#else
+# error Unimplemented!
+#endif
+}
+
+/**
+ * Gets the value of a thread-local variable for the calling thread.
+ * This function cannot fail.
+ * @return the value associated with the given variable for the calling
+ * or NULL if there is no value.
+ */
+void *vlc_threadvar_get (vlc_threadvar_t key)
+{
+#if defined(LIBVLC_USE_PTHREAD)
+ return pthread_getspecific (key);
+#elif defined( UNDER_CE ) || defined( WIN32 )
+ return TlsGetValue (key);
+#else
+# error Unimplemented!
+#endif
+}
+
#if defined (LIBVLC_USE_PTHREAD)
#elif defined (WIN32)
static unsigned __stdcall vlc_entry (void *data)
{
vlc_cancel_t cancel_data = VLC_CANCEL_INIT;
vlc_thread_t self = data;
+#ifdef UNDER_CE
+ cancel_data.cancel_event = self->cancel_event;
+#endif
- vlc_threadvar_set (&cancel_key, &cancel_data);
+ vlc_threadvar_set (cancel_key, &cancel_data);
self->data = self->entry (self->data);
return 0;
}
sigaddset (&set, SIGPIPE); /* We don't want this one, really! */
pthread_sigmask (SIG_BLOCK, &set, &oldset);
}
+
+#if (_POSIX_THREAD_PRIORITY_SCHEDULING >= 0)
{
struct sched_param sp = { .sched_priority = priority, };
int policy;
pthread_attr_setschedpolicy (&attr, policy);
pthread_attr_setschedparam (&attr, &sp);
}
+#else
+ (void) priority;
+#endif
+
+ /* The thread stack size.
+ * The lower the value, the less address space per thread, the highest
+ * maximum simultaneous threads per process. Too low values will cause
+ * stack overflows and weird crashes. Set with caution. Also keep in mind
+ * that 64-bits platforms consume more stack than 32-bits one.
+ *
+ * Thanks to on-demand paging, thread stack size only affects address space
+ * consumption. In terms of memory, threads only use what they need
+ * (rounded up to the page boundary).
+ *
+ * For example, on Linux i386, the default is 2 mega-bytes, which supports
+ * about 320 threads per processes. */
+#define VLC_STACKSIZE (128 * sizeof (void *) * 1024)
+
+#ifdef VLC_STACKSIZE
+ ret = pthread_attr_setstacksize (&attr, VLC_STACKSIZE);
+ assert (ret == 0); /* fails iif VLC_STACKSIZE is invalid */
+#endif
ret = pthread_create (p_handle, &attr, entry, data);
pthread_sigmask (SIG_SETMASK, &oldset, NULL);
th->data = data;
th->entry = entry;
#if defined( UNDER_CE )
- hThread = CreateThread (NULL, 0, vlc_entry, th, CREATE_SUSPENDED, NULL);
+ th->cancel_event = CreateEvent (NULL, FALSE, FALSE, NULL);
+ if (th->cancel_event == NULL)
+ {
+ free(th);
+ return errno;
+ }
+ hThread = CreateThread (NULL, 128*1024, vlc_entry, th, CREATE_SUSPENDED, NULL);
#else
hThread = (HANDLE)(uintptr_t)
_beginthreadex (NULL, 0, vlc_entry, th, CREATE_SUSPENDED, NULL);
if (hThread)
{
+#ifndef UNDER_CE
/* Thread closes the handle when exiting, duplicate it here
* to be on the safe side when joining. */
if (!DuplicateHandle (GetCurrentProcess (), hThread,
free (th);
return ENOMEM;
}
+#else
+ th->handle = hThread;
+#endif
ResumeThread (hThread);
if (priority)
free (th);
}
-#elif defined( HAVE_KERNEL_SCHEDULER_H )
- *p_handle = spawn_thread( entry, psz_name, priority, data );
- ret = resume_thread( *p_handle );
-
#endif
return ret;
}
{
#if defined (LIBVLC_USE_PTHREAD_CANCEL)
pthread_cancel (thread_id);
+#elif defined (UNDER_CE)
+ SetEvent (thread_id->cancel_event);
#elif defined (WIN32)
QueueUserAPC (vlc_cancel_self, thread_id->handle, 0);
#else
{
#if defined( LIBVLC_USE_PTHREAD )
int val = pthread_join (handle, result);
- if (val)
- vlc_thread_fatal ("joining thread", val, __func__, __FILE__, __LINE__);
+ VLC_THREAD_ASSERT ("joining thread");
#elif defined( UNDER_CE ) || defined( WIN32 )
do
CloseHandle (handle->handle);
if (result)
*result = handle->data;
+#if defined( UNDER_CE )
+ CloseHandle (handle->cancel_event);
+#endif
free (handle);
-#elif defined( HAVE_KERNEL_SCHEDULER_H )
- int32_t exit_value;
- int val = (B_OK == wait_for_thread( p_priv->thread_id, &exit_value ));
- if( !val && result )
- *result = (void *)exit_value;
+#endif
+}
+
+/**
+ * Save the current cancellation state (enabled or disabled), then disable
+ * cancellation for the calling thread.
+ * This function must be called before entering a piece of code that is not
+ * cancellation-safe, unless it can be proven that the calling thread will not
+ * be cancelled.
+ * @return Previous cancellation state (opaque value for vlc_restorecancel()).
+ */
+int vlc_savecancel (void)
+{
+ int state;
+
+#if defined (LIBVLC_USE_PTHREAD_CANCEL)
+ int val = pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
+ VLC_THREAD_ASSERT ("saving cancellation");
+
+#else
+ vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
+ if (nfo == NULL)
+ return false; /* Main thread - cannot be cancelled anyway */
+
+ state = nfo->killable;
+ nfo->killable = false;
+
+#endif
+ return state;
+}
+
+/**
+ * Restore the cancellation state for the calling thread.
+ * @param state previous state as returned by vlc_savecancel().
+ * @return Nothing, always succeeds.
+ */
+void vlc_restorecancel (int state)
+{
+#if defined (LIBVLC_USE_PTHREAD_CANCEL)
+# ifndef NDEBUG
+ int oldstate, val;
+
+ val = pthread_setcancelstate (state, &oldstate);
+ /* This should fail if an invalid value for given for state */
+ VLC_THREAD_ASSERT ("restoring cancellation");
+
+ if (oldstate != PTHREAD_CANCEL_DISABLE)
+ vlc_thread_fatal ("restoring cancellation while not disabled", EINVAL,
+ __func__, __FILE__, __LINE__);
+# else
+ pthread_setcancelstate (state, NULL);
+# endif
+
+#else
+ vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
+ assert (state == false || state == true);
+
+ if (nfo == NULL)
+ return; /* Main thread - cannot be cancelled anyway */
+
+ assert (!nfo->killable);
+ nfo->killable = state != 0;
#endif
}
+/**
+ * Issues an explicit deferred cancellation point.
+ * This has no effect if thread cancellation is disabled.
+ * This can be called when there is a rather slow non-sleeping operation.
+ * This is also used to force a cancellation point in a function that would
+ * otherwise "not always" be a one (block_FifoGet() is an example).
+ */
+void vlc_testcancel (void)
+{
+#if defined (LIBVLC_USE_PTHREAD_CANCEL)
+ pthread_testcancel ();
+
+#else
+ vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
+ if (nfo == NULL)
+ return; /* Main thread - cannot be cancelled anyway */
+
+ if (nfo->killable && nfo->killed)
+ {
+ for (vlc_cleanup_t *p = nfo->cleaners; p != NULL; p = p->next)
+ p->proc (p->data);
+# if defined (LIBVLC_USE_PTHREAD)
+ pthread_exit (PTHREAD_CANCELLED);
+# elif defined (UNDER_CE)
+ ExitThread(0);
+# elif defined (WIN32)
+ _endthread ();
+# else
+# error Not implemented!
+# endif
+ }
+#endif
+}
+
struct vlc_thread_boot
{
return NULL;
}
+#undef vlc_thread_create
/*****************************************************************************
- * vlc_thread_create: create a thread, inner version
+ * vlc_thread_create: create a thread
*****************************************************************************
* Note that i_priority is only taken into account on platforms supporting
* userland real-time priority threads.
*****************************************************************************/
-int __vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
- const char *psz_name, void * ( *func ) ( vlc_object_t * ),
- int i_priority, bool b_wait )
+int vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
+ const char *psz_name, void *(*func) ( vlc_object_t * ),
+ int i_priority )
{
int i_ret;
vlc_object_internals_t *p_priv = vlc_internals( p_this );
boot->entry = func;
boot->object = p_this;
- vlc_object_lock( p_this );
-
/* Make sure we don't re-create a thread if the object has already one */
assert( !p_priv->b_thread );
}
#endif
+ p_priv->b_thread = true;
i_ret = vlc_clone( &p_priv->thread_id, thread_entry, boot, i_priority );
if( i_ret == 0 )
- {
- if( b_wait )
- {
- msg_Dbg( p_this, "waiting for thread initialization" );
- vlc_object_wait( p_this );
- }
-
- p_priv->b_thread = true;
- msg_Dbg( p_this, "thread %lu (%s) created at priority %d (%s:%d)",
- (unsigned long)p_priv->thread_id, psz_name, i_priority,
- psz_file, i_line );
- }
+ msg_Dbg( p_this, "thread (%s) created at priority %d (%s:%d)",
+ psz_name, i_priority, psz_file, i_line );
else
{
+ p_priv->b_thread = false;
errno = i_ret;
msg_Err( p_this, "%s thread could not be created at %s:%d (%m)",
psz_name, psz_file, i_line );
}
- vlc_object_unlock( p_this );
return i_ret;
}
FILETIME create_ft, exit_ft, kernel_ft, user_ft;
int64_t real_time, kernel_time, user_time;
+#ifndef UNDER_CE
if( ! DuplicateHandle(GetCurrentProcess(),
p_priv->thread_id->handle,
GetCurrentProcess(),
p_priv->b_thread = false;
return; /* We have a problem! */
}
+#else
+ hThread = p_priv->thread_id->handle;
+#endif
vlc_join( p_priv->thread_id, NULL );
#else
va_list ap;
- va_start (ap, cmd);
-
- vlc_cancel_t *nfo = vlc_threadvar_get (&cancel_key);
+ vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
if (nfo == NULL)
{
#ifdef WIN32
if (nfo == NULL)
return; /* Uho! Expect problems! */
*nfo = VLC_CANCEL_INIT;
- vlc_threadvar_set (&cancel_key, nfo);
+ vlc_threadvar_set (cancel_key, nfo);
#endif
}
+ va_start (ap, cmd);
switch (cmd)
{
- case VLC_SAVE_CANCEL:
- {
- int *p_state = va_arg (ap, int *);
- *p_state = nfo->killable;
- nfo->killable = false;
- break;
- }
-
- case VLC_RESTORE_CANCEL:
- {
- int state = va_arg (ap, int);
- nfo->killable = state != 0;
- break;
- }
-
- case VLC_TEST_CANCEL:
- if (nfo->killable && nfo->killed)
- {
- for (vlc_cleanup_t *p = nfo->cleaners; p != NULL; p = p->next)
- p->proc (p->data);
- free (nfo);
-#if defined (LIBVLC_USE_PTHREAD)
- pthread_exit (PTHREAD_CANCELLED);
-#elif defined (WIN32)
- _endthread ();
-#else
-# error Not implemented!
-#endif
- }
- break;
-
case VLC_DO_CANCEL:
nfo->killed = true;
break;