* This header provides portable declarations for mutexes & conditions
*****************************************************************************
* Copyright (C) 1999, 2002 the VideoLAN team
- * $Id$
+ * Copyright © 2007-2008 Rémi Denis-Courmont
*
* Authors: Jean-Marc Dressler <polux@via.ecp.fr>
* Samuel Hocevar <sam@via.ecp.fr>
#ifndef VLC_THREADS_H_
#define VLC_THREADS_H_
+/**
+ * \file
+ * This file defines structures and functions for handling threads in vlc
+ *
+ */
+
#if defined( UNDER_CE )
/* WinCE API */
#elif defined( WIN32 )
#else /* pthreads (like Linux & BSD) */
# define LIBVLC_USE_PTHREAD 1
+# define LIBVLC_USE_PTHREAD_CANCEL 1
# define _APPLE_C_SOURCE 1 /* Proper pthread semantics on OSX */
# include <stdlib.h> /* lldiv_t definition (only in C99) */
typedef pthread_key_t vlc_threadvar_t;
#elif defined( WIN32 ) || defined( UNDER_CE )
-typedef HANDLE vlc_thread_t;
-typedef BOOL (WINAPI *SIGNALOBJECTANDWAIT) ( HANDLE, HANDLE, DWORD, BOOL );
+typedef struct
+{
+ HANDLE handle;
+ void *(*entry) (void *);
+ void *data;
+} *vlc_thread_t;
+
typedef HANDLE vlc_mutex_t;
typedef HANDLE vlc_cond_t;
typedef DWORD vlc_threadvar_t;
VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t *, const char *, int ) );
+VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) );
+VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
+VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
+VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
+
+#ifndef LIBVLC_USE_PTHREAD_CANCEL
+enum {
+ VLC_SAVE_CANCEL,
+ VLC_RESTORE_CANCEL,
+ VLC_TEST_CANCEL,
+ VLC_DO_CANCEL,
+ VLC_CLEANUP_PUSH,
+ VLC_CLEANUP_POP,
+};
+#endif
+
#define vlc_thread_ready vlc_object_signal
/*****************************************************************************
#define vlc_mutex_destroy( P_MUTEX ) \
__vlc_mutex_destroy( __FILE__, __LINE__, P_MUTEX )
+/**
+ * Save the cancellation state and disable cancellation for the calling thread.
+ * This function must be called before entering a piece of code that is not
+ * cancellation-safe.
+ * @return Previous cancellation state (opaque value).
+ */
+static inline int vlc_savecancel (void)
+{
+ int state;
+#if defined (LIBVLC_USE_PTHREAD_CANCEL)
+ (void) pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
+#else
+ vlc_control_cancel (VLC_SAVE_CANCEL, &state);
+#endif
+ return state;
+}
+
+/**
+ * Restore the cancellation state for the calling thread.
+ * @param state previous state as returned by vlc_savecancel().
+ * @return Nothing, always succeeds.
+ */
+static inline void vlc_restorecancel (int state)
+{
+#if defined (LIBVLC_USE_PTHREAD_CANCEL)
+ (void) pthread_setcancelstate (state, NULL);
+#else
+ vlc_control_cancel (VLC_RESTORE_CANCEL, state);
+#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.
+ */
+static inline void vlc_testcancel (void)
+{
+#if defined (LIBVLC_USE_PTHREAD_CANCEL)
+ pthread_testcancel ();
+#else
+ vlc_control_cancel (VLC_TEST_CANCEL);
+#endif
+}
+
+#if defined (LIBVLC_USE_PTHREAD_CANCEL)
+/**
+ * Registers a new procedure to run if the thread is cancelled (or otherwise
+ * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
+ * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
+ * of the block between these two function calls is not allowed (read: it will
+ * likely crash the whole process). If multiple procedures are registered,
+ * they are handled in last-in first-out order.
+ *
+ * @param routine procedure to call if the thread ends
+ * @param arg argument for the procedure
+ */
+# define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
+
+/**
+ * Removes a cleanup procedure that was previously registered with
+ * vlc_cleanup_push().
+ */
+# define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
+
+/**
+ * Removes a cleanup procedure that was previously registered with
+ * vlc_cleanup_push(), and executes it.
+ */
+# define vlc_cleanup_run( ) pthread_cleanup_pop (1)
+#else
+typedef struct vlc_cleanup_t vlc_cleanup_t;
+
+struct vlc_cleanup_t
+{
+ vlc_cleanup_t *next;
+ void (*proc) (void *);
+ void *data;
+};
+
+/* This macros opens a code block on purpose. This is needed for multiple
+ * calls within a single function. This also prevent Win32 developpers from
+ * writing code that would break on POSIX (POSIX opens a block as well). */
+# define vlc_cleanup_push( routine, arg ) \
+ do { \
+ vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
+ vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
+
+# define vlc_cleanup_pop( ) \
+ vlc_control_cancel (VLC_CLEANUP_POP); \
+ } while (0)
+
+# define vlc_cleanup_run( ) \
+ vlc_control_cancel (VLC_CLEANUP_POP); \
+ vlc_cleanup_data.proc (vlc_cleanup_data.data); \
+ } while (0)
+
+#endif /* LIBVLC_USE_PTHREAD_CANCEL */
+
+static inline void vlc_cleanup_lock (void *lock)
+{
+ vlc_mutex_unlock ((vlc_mutex_t *)lock);
+}
+#define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
+
/*****************************************************************************
* vlc_cond_init: initialize a condition
*****************************************************************************/
vlc_mutex_lock( p_mutex );
#elif defined( WIN32 )
- (void)psz_file; (void)i_line;
+ DWORD result;
- /* Increase our wait count */
- SignalObjectAndWait( *p_mutex, *p_condvar, INFINITE, FALSE );
+ do
+ {
+ vlc_testcancel ();
+ result = SignalObjectAndWait (*p_mutex, *p_condvar, INFINITE, TRUE);
- /* Reacquire the mutex before returning. */
- vlc_mutex_lock( p_mutex );
+ /* Reacquire the mutex before returning. */
+ vlc_mutex_lock( p_mutex );
+ }
+ while (result == WAIT_IO_COMPLETION);
+
+ vlc_testcancel ();
+
+ (void)psz_file; (void)i_line;
#elif defined( SYS_BEOS )
/* The p_condvar->thread var is initialized before the unlock because
struct timespec ts = { d.quot, d.rem * 1000 };
int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
- if (val == ETIMEDOUT)
- return ETIMEDOUT; /* this error is perfectly normal */
- VLC_THREAD_ASSERT ("timed-waiting on condition");
+ if (val != ETIMEDOUT)
+ VLC_THREAD_ASSERT ("timed-waiting on condition");
+ return val;
#elif defined( UNDER_CE )
mtime_t delay_ms = (deadline - mdate())/1000;
/* Reacquire the mutex before returning. */
vlc_mutex_lock( p_mutex );
- if(result == WAIT_TIMEOUT)
- return ETIMEDOUT; /* this error is perfectly normal */
-
(void)psz_file; (void)i_line;
+ return (result == WAIT_TIMEOUT) ? ETIMEDOUT : 0;
+
#elif defined( WIN32 )
- mtime_t total = (deadline - mdate())/1000;
- DWORD result;
- if( total < 0 )
- total = 0;
+ mtime_t total;
+ DWORD result = WAIT_TIMEOUT;
- do
+ (void)psz_file; (void)i_line;
+
+ vlc_testcancel ();
+ while ((total = (deadline - mdate ()) > 0))
{
DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
result = SignalObjectAndWait( *p_mutex, *p_condvar,
- delay, FALSE );
- total -= delay;
+ delay, TRUE );
+
+ /* Reacquire the mutex before return/cancel. */
vlc_mutex_lock (p_mutex);
+ if (result == WAIT_OBJECT_0)
+ return 0; /* Condition signaled! */
+ vlc_testcancel ();
}
- while (total);
-
- /* Reacquire the mutex before returning. */
- if(result == WAIT_TIMEOUT)
- return ETIMEDOUT; /* this error is perfectly normal */
-
- (void)psz_file; (void)i_line;
+ return ETIMEDOUT;
#elif defined( SYS_BEOS )
# error Unimplemented
#endif
-
- return 0;
}
/*****************************************************************************
#elif defined(__i386__)
asm volatile ("mfence":::"memory");
#else
- vlc_spin_t spin;
+ vlc_spinlock_t spin;
vlc_spin_init (&spin);
vlc_spin_lock (&spin);
vlc_spin_unlock (&spin);
projects / vlc / blobdiff