/*****************************************************************************
* vlc_threads.h : threads implementation for the VideoLAN client
* This header provides portable declarations for mutexes & conditions
*****************************************************************************
* Copyright (C) 1999, 2002 the VideoLAN team
* Copyright © 2007-2008 Rémi Denis-Courmont
*
* Authors: Jean-Marc Dressler <polux@via.ecp.fr>
* Samuel Hocevar <sam@via.ecp.fr>
* Gildas Bazin <gbazin@netcourrier.com>
* Christophe Massiot <massiot@via.ecp.fr>
*
* 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
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifndef VLC_THREADS_H_
#define VLC_THREADS_H_
/**
* \file
* This file defines structures and functions for handling threads in vlc
*
*/
#if defined( UNDER_CE )
# include <errno.h> /* WinCE API */
#elif defined( WIN32 )
# include <process.h> /* Win32 API */
# include <errno.h>
#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) */
# include <unistd.h> /* _POSIX_SPIN_LOCKS */
# include <pthread.h>
/* Needed for pthread_cond_timedwait */
# include <errno.h>
# include <time.h>
#endif
/*****************************************************************************
* Constants
*****************************************************************************/
/* Thread priorities */
#ifdef __APPLE__
# define VLC_THREAD_PRIORITY_LOW 0
# define VLC_THREAD_PRIORITY_INPUT 22
# define VLC_THREAD_PRIORITY_AUDIO 22
# define VLC_THREAD_PRIORITY_VIDEO 0
# define VLC_THREAD_PRIORITY_OUTPUT 22
# define VLC_THREAD_PRIORITY_HIGHEST 22
#elif defined(LIBVLC_USE_PTHREAD)
# define VLC_THREAD_PRIORITY_LOW 0
# define VLC_THREAD_PRIORITY_INPUT 10
# define VLC_THREAD_PRIORITY_AUDIO 5
# define VLC_THREAD_PRIORITY_VIDEO 0
# define VLC_THREAD_PRIORITY_OUTPUT 15
# define VLC_THREAD_PRIORITY_HIGHEST 20
#elif defined(WIN32) || defined(UNDER_CE)
/* Define different priorities for WinNT/2K/XP and Win9x/Me */
# define VLC_THREAD_PRIORITY_LOW 0
# define VLC_THREAD_PRIORITY_INPUT \
THREAD_PRIORITY_ABOVE_NORMAL
# define VLC_THREAD_PRIORITY_AUDIO \
THREAD_PRIORITY_HIGHEST
# define VLC_THREAD_PRIORITY_VIDEO 0
# define VLC_THREAD_PRIORITY_OUTPUT \
THREAD_PRIORITY_ABOVE_NORMAL
# define VLC_THREAD_PRIORITY_HIGHEST \
THREAD_PRIORITY_TIME_CRITICAL
#else
# define VLC_THREAD_PRIORITY_LOW 0
# define VLC_THREAD_PRIORITY_INPUT 0
# define VLC_THREAD_PRIORITY_AUDIO 0
# define VLC_THREAD_PRIORITY_VIDEO 0
# define VLC_THREAD_PRIORITY_OUTPUT 0
# define VLC_THREAD_PRIORITY_HIGHEST 0
#endif
/*****************************************************************************
* Type definitions
*****************************************************************************/
#if defined (LIBVLC_USE_PTHREAD)
typedef pthread_t vlc_thread_t;
typedef pthread_mutex_t vlc_mutex_t;
#define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
typedef pthread_cond_t vlc_cond_t;
typedef pthread_key_t vlc_threadvar_t;
#elif defined( WIN32 )
typedef struct
{
HANDLE handle;
void *(*entry) (void *);
void *data;
#if defined( UNDER_CE )
HANDLE cancel_event;
#endif
} *vlc_thread_t;
typedef struct
{
LONG initialized;
CRITICAL_SECTION mutex;
} vlc_mutex_t;
#define VLC_STATIC_MUTEX { 0, }
typedef HANDLE vlc_cond_t;
typedef DWORD vlc_threadvar_t;
#endif
#if defined( WIN32 ) && !defined ETIMEDOUT
# define ETIMEDOUT 10060 /* This is the value in winsock.h. */
#endif
/*****************************************************************************
* Function definitions
*****************************************************************************/
VLC_EXPORT( int, vlc_mutex_init, ( vlc_mutex_t * ) );
VLC_EXPORT( int, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
VLC_EXPORT( void, vlc_mutex_destroy, ( vlc_mutex_t * ) );
VLC_EXPORT( void, vlc_mutex_lock, ( vlc_mutex_t * ) );
VLC_EXPORT( int, vlc_mutex_trylock, ( vlc_mutex_t * ) );
VLC_EXPORT( void, vlc_mutex_unlock, ( vlc_mutex_t * ) );
VLC_EXPORT( int, vlc_cond_init, ( vlc_cond_t * ) );
VLC_EXPORT( void, vlc_cond_destroy, ( vlc_cond_t * ) );
VLC_EXPORT( void, vlc_cond_signal, (vlc_cond_t *) );
VLC_EXPORT( void, vlc_cond_broadcast, (vlc_cond_t *) );
VLC_EXPORT( void, vlc_cond_wait, (vlc_cond_t *, vlc_mutex_t *) );
VLC_EXPORT( int, vlc_cond_timedwait, (vlc_cond_t *, vlc_mutex_t *, mtime_t) );
VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
VLC_EXPORT( int, vlc_threadvar_set, (vlc_threadvar_t, void *) );
VLC_EXPORT( void *, vlc_threadvar_get, (vlc_threadvar_t) );
VLC_EXPORT( int, vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int ) );
VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t * ) );
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_DO_CANCEL,
VLC_CLEANUP_PUSH,
VLC_CLEANUP_POP,
};
#endif
VLC_EXPORT( int, vlc_savecancel, (void) );
VLC_EXPORT( void, vlc_restorecancel, (int state) );
VLC_EXPORT( void, vlc_testcancel, (void) );
#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 developers 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)
# if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
typedef pthread_spinlock_t vlc_spinlock_t;
/**
* Initializes a spinlock.
*/
static inline int vlc_spin_init (vlc_spinlock_t *spin)
{
return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
}
/**
* Acquires a spinlock.
*/
static inline void vlc_spin_lock (vlc_spinlock_t *spin)
{
pthread_spin_lock (spin);
}
/**
* Releases a spinlock.
*/
static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
{
pthread_spin_unlock (spin);
}
/**
* Deinitializes a spinlock.
*/
static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
{
pthread_spin_destroy (spin);
}
#elif defined( WIN32 )
typedef CRITICAL_SECTION vlc_spinlock_t;
/**
* Initializes a spinlock.
*/
static inline int vlc_spin_init (vlc_spinlock_t *spin)
{
#ifdef UNDER_CE
InitializeCriticalSection(spin);
return 0;
#else
return !InitializeCriticalSectionAndSpinCount(spin, 4000);
#endif
}
/**
* Acquires a spinlock.
*/
static inline void vlc_spin_lock (vlc_spinlock_t *spin)
{
EnterCriticalSection(spin);
}
/**
* Releases a spinlock.
*/
static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
{
LeaveCriticalSection(spin);
}
/**
* Deinitializes a spinlock.
*/
static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
{
DeleteCriticalSection(spin);
}
#else
/* Fallback to plain mutexes if spinlocks are not available */
typedef vlc_mutex_t vlc_spinlock_t;
static inline int vlc_spin_init (vlc_spinlock_t *spin)
{
return vlc_mutex_init (spin);
}
# define vlc_spin_lock vlc_mutex_lock
# define vlc_spin_unlock vlc_mutex_unlock
# define vlc_spin_destroy vlc_mutex_destroy
#endif
/**
* Issues a full memory barrier.
*/
#if defined (__APPLE__)
# include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
#endif
static inline void barrier (void)
{
#if defined (__GNUC__) && !defined (__APPLE__) && \
((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
__sync_synchronize ();
#elif defined(__APPLE__)
OSMemoryBarrier ();
#elif defined(__powerpc__)
asm volatile ("sync":::"memory");
#elif 0 // defined(__i386__) /* Requires SSE2 support */
asm volatile ("mfence":::"memory");
#else
vlc_spinlock_t spin;
vlc_spin_init (&spin);
vlc_spin_lock (&spin);
vlc_spin_unlock (&spin);
vlc_spin_destroy (&spin);
#endif
}
/*****************************************************************************
* vlc_thread_create: create a thread
*****************************************************************************/
#define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY ) \
vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY )
/*****************************************************************************
* vlc_thread_set_priority: set the priority of the calling thread
*****************************************************************************/
#define vlc_thread_set_priority( P_THIS, PRIORITY ) \
__vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
/*****************************************************************************
* vlc_thread_join: wait until a thread exits
*****************************************************************************/
#define vlc_thread_join( P_THIS ) \
__vlc_thread_join( VLC_OBJECT(P_THIS) )
#ifdef __cplusplus
/**
* Helper C++ class to lock a mutex.
* The mutex is locked when the object is created, and unlocked when the object
* is destroyed.
*/
class vlc_mutex_locker
{
private:
vlc_mutex_t *lock;
public:
vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
{
vlc_mutex_lock (lock);
}
~vlc_mutex_locker (void)
{
vlc_mutex_unlock (lock);
}
};
#endif
#endif /* !_VLC_THREADS_H */
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