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Commit fb671394 authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont
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Split pthread and Win32 code into separate files

parent 34f76d16
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Showing with 1110 additions and 1056 deletions
src/Makefile.am
View file @ fb671394
...@@ -238,22 +238,28 @@ endif ...@@ -238,22 +238,28 @@ endif
endif endif
SOURCES_libvlc_beos = \ SOURCES_libvlc_beos = \
misc/pthread.c \
$(NULL) $(NULL)
SOURCES_libvlc_darwin = \ SOURCES_libvlc_darwin = \
misc/pthread.c \
misc/darwin_specific.c \ misc/darwin_specific.c \
$(NULL) $(NULL)
SOURCES_libvlc_linux = \ SOURCES_libvlc_linux = \
misc/pthread.c \
misc/linux_specific.c \ misc/linux_specific.c \
$(NULL) $(NULL)
SOURCES_libvlc_win32 = \ SOURCES_libvlc_win32 = \
misc/w32thread.c \
misc/win32_specific.c \ misc/win32_specific.c \
network/winsock.c \ network/winsock.c \
$(NULL) $(NULL)
SOURCES_libvlc_other = misc/not_specific.c SOURCES_libvlc_other = \
misc/pthread.c \
misc/not_specific.c
SOURCES_libvlc_dirent = \ SOURCES_libvlc_dirent = \
extras/dirent.c \ extras/dirent.c \
......
src/misc/pthread.c 0 → 100644
View file @ fb671394
/*****************************************************************************
* pthread.c : pthread back-end for LibVLC
*****************************************************************************
* Copyright (C) 1999-2009 the VideoLAN team
*
* Authors: Jean-Marc Dressler <polux@via.ecp.fr>
* 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
* 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.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <vlc_common.h>
#include "libvlc.h"
#include <stdarg.h>
#include <assert.h>
#include <unistd.h> /* fsync() */
#include <signal.h>
#include <sched.h>
#ifdef __linux__
# include <sys/syscall.h> /* SYS_gettid */
#endif
#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.
*/
void vlc_trace (const char *fn, const char *file, unsigned line)
{
fprintf (stderr, "at %s:%u in %s\n", file, line, fn);
fflush (stderr); /* needed before switch to low-level I/O */
#ifdef HAVE_BACKTRACE
void *stack[20];
int len = backtrace (stack, sizeof (stack) / sizeof (stack[0]));
backtrace_symbols_fd (stack, len, 2);
#endif
fsync (2);
}
static inline unsigned long vlc_threadid (void)
{
#if defined (__linux__)
/* glibc does not provide a call for this */
return syscall (SYS_gettid);
#else
union { pthread_t th; unsigned long int i; } v = { };
v.th = pthread_self ();
return v.i;
#endif
}
#ifndef NDEBUG
/*****************************************************************************
* vlc_thread_fatal: Report an error from the threading layer
*****************************************************************************
* This is mostly meant for debugging.
*****************************************************************************/
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 ());
vlc_trace (function, file, line);
/* Sometimes strerror_r() crashes too, so make sure we print an error
* message before we invoke it */
#ifdef __GLIBC__
/* Avoid the strerror_r() prototype brain damage in glibc */
errno = error;
fprintf (stderr, " Error message: %m\n");
#else
char buf[1000];
const char *msg;
switch (strerror_r (error, buf, sizeof (buf)))
{
case 0:
msg = buf;
break;
case ERANGE: /* should never happen */
msg = "unknwon (too big to display)";
break;
default:
msg = "unknown (invalid error number)";
break;
}
fprintf (stderr, " Error message: %s\n", msg);
#endif
fflush (stderr);
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
#if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
/* This is not prototyped under glibc, though it exists. */
int pthread_mutexattr_setkind_np( pthread_mutexattr_t *attr, int kind );
#endif
/*****************************************************************************
* vlc_mutex_init: initialize a mutex
*****************************************************************************/
int vlc_mutex_init( vlc_mutex_t *p_mutex )
{
pthread_mutexattr_t attr;
int i_result;
pthread_mutexattr_init( &attr );
#ifndef NDEBUG
/* Create error-checking mutex to detect problems more easily. */
# if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
# else
pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
# endif
#endif
i_result = pthread_mutex_init( p_mutex, &attr );
pthread_mutexattr_destroy( &attr );
return i_result;
}
/*****************************************************************************
* vlc_mutex_init: initialize a recursive mutex (Do not use)
*****************************************************************************/
int vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
{
pthread_mutexattr_t attr;
int i_result;
pthread_mutexattr_init( &attr );
#if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_RECURSIVE_NP );
#else
pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
#endif
i_result = pthread_mutex_init( p_mutex, &attr );
pthread_mutexattr_destroy( &attr );
return( i_result );
}
/**
* 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)
{
int val = pthread_mutex_destroy( p_mutex );
VLC_THREAD_ASSERT ("destroying mutex");
}
#ifndef 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
/**
* 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)
{
int val = pthread_mutex_lock( p_mutex );
VLC_THREAD_ASSERT ("locking 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)
{
int val = pthread_mutex_trylock( p_mutex );
if (val != EBUSY)
VLC_THREAD_ASSERT ("locking mutex");
return val;
}
/**
* 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)
{
int val = pthread_mutex_unlock( p_mutex );
VLC_THREAD_ASSERT ("unlocking mutex");
}
/*****************************************************************************
* vlc_cond_init: initialize a condition variable
*****************************************************************************/
int vlc_cond_init( vlc_cond_t *p_condvar )
{
pthread_condattr_t attr;
int ret;
ret = pthread_condattr_init (&attr);
if (ret)
return ret;
#if !defined (_POSIX_CLOCK_SELECTION)
/* Fairly outdated POSIX support (that was defined in 2001) */
# define _POSIX_CLOCK_SELECTION (-1)
#endif
#if (_POSIX_CLOCK_SELECTION >= 0)
/* NOTE: This must be the same clock as the one in mtime.c */
pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
#endif
ret = pthread_cond_init (p_condvar, &attr);
pthread_condattr_destroy (&attr);
return ret;
}
/**
* 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)
{
int val = pthread_cond_destroy( p_condvar );
VLC_THREAD_ASSERT ("destroying condition");
}
/**
* 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)
{
int val = pthread_cond_signal( p_condvar );
VLC_THREAD_ASSERT ("signaling condition variable");
}
/**
* 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)
{
pthread_cond_broadcast (p_condvar);
}
/**
* 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)
{
int val = pthread_cond_wait( p_condvar, p_mutex );
VLC_THREAD_ASSERT ("waiting on condition");
}
/**
* 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)
{
#ifdef __APPLE__
/* mdate() is mac_absolute_time on OSX, which we must convert to do
* the same base than gettimeofday() which pthread_cond_timedwait
* relies 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) };
int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
if (val != ETIMEDOUT)
VLC_THREAD_ASSERT ("timed-waiting on condition");
return val;
}
/**
* Allocates a thread-specific variable.
* @param key where to store the thread-specific variable handle
* @param destr a destruction callback. It is called whenever a thread exits
* and the thread-specific variable has a non-NULL value.
* @return 0 on success, a system error code otherwise. This function can
* actually fail because there is a fixed limit on the number of
* thread-specific variable in a process on most systems.
*/
int vlc_threadvar_create (vlc_threadvar_t *key, void (*destr) (void *))
{
return pthread_key_create (key, destr);
}
void vlc_threadvar_delete (vlc_threadvar_t *p_tls)
{
pthread_key_delete (*p_tls);
}
/**
* Sets a thread-specific 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)
{
return pthread_setspecific (key, value);
}
/**
* 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)
{
return pthread_getspecific (key);
}
/**
* Creates and starts new thread.
*
* @param p_handle [OUT] pointer to write the handle of the created thread to
* @param entry entry point for the thread
* @param data data parameter given to the entry point
* @param priority thread priority value
* @return 0 on success, a standard error code on error.
*/
int vlc_clone (vlc_thread_t *p_handle, void * (*entry) (void *), void *data,
int priority)
{
int ret;
pthread_attr_t attr;
pthread_attr_init (&attr);
/* Block the signals that signals interface plugin handles.
* If the LibVLC caller wants to handle some signals by itself, it should
* block these before whenever invoking LibVLC. And it must obviously not
* start the VLC signals interface plugin.
*
* LibVLC will normally ignore any interruption caused by an asynchronous
* signal during a system call. But there may well be some buggy cases
* where it fails to handle EINTR (bug reports welcome). Some underlying
* libraries might also not handle EINTR properly.
*/
sigset_t oldset;
{
sigset_t set;
sigemptyset (&set);
sigdelset (&set, SIGHUP);
sigaddset (&set, SIGINT);
sigaddset (&set, SIGQUIT);
sigaddset (&set, SIGTERM);
sigaddset (&set, SIGPIPE); /* We don't want this one, really! */
pthread_sigmask (SIG_BLOCK, &set, &oldset);
}
#if defined (_POSIX_PRIORITY_SCHEDULING) && (_POSIX_PRIORITY_SCHEDULING >= 0) \
&& defined (_POSIX_THREAD_PRIORITY_SCHEDULING) \
&& (_POSIX_THREAD_PRIORITY_SCHEDULING >= 0)
{
struct sched_param sp = { .sched_priority = priority, };
int policy;
if (sp.sched_priority <= 0)
sp.sched_priority += sched_get_priority_max (policy = SCHED_OTHER);
else
sp.sched_priority += sched_get_priority_min (policy = SCHED_RR);
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);
pthread_attr_destroy (&attr);
return ret;
}
/**
* Marks a thread as cancelled. Next time the target thread reaches a
* cancellation point (while not having disabled cancellation), it will
* run its cancellation cleanup handler, the thread variable destructors, and
* terminate. vlc_join() must be used afterward regardless of a thread being
* cancelled or not.
*/
void vlc_cancel (vlc_thread_t thread_id)
{
pthread_cancel (thread_id);
}
/**
* Waits for a thread to complete (if needed), and destroys it.
* This is a cancellation point; in case of cancellation, the join does _not_
* occur.
*
* @param handle thread handle
* @param p_result [OUT] pointer to write the thread return value or NULL
* @return 0 on success, a standard error code otherwise.
*/
void vlc_join (vlc_thread_t handle, void **result)
{
int val = pthread_join (handle, result);
VLC_THREAD_ASSERT ("joining thread");
}
/**
* 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;
int val = pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
VLC_THREAD_ASSERT ("saving cancellation");
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)
{
#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
}
/**
* 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)
{
pthread_testcancel ();
}
void vlc_control_cancel (int cmd, ...)
{
(void) cmd;
assert (0);
}
src/misc/threads.c
View file @ fb671394
...@@ -32,1017 +32,14 @@ ...@@ -32,1017 +32,14 @@
#include <vlc_common.h> #include <vlc_common.h>
#include "libvlc.h" #include "libvlc.h"
#include <stdarg.h>
#include <assert.h> #include <assert.h>
#ifdef HAVE_UNISTD_H #ifdef HAVE_UNISTD_H
# include <unistd.h> # include <unistd.h>
#endif #endif
#include <signal.h>
#if defined( LIBVLC_USE_PTHREAD ) #if defined( LIBVLC_USE_PTHREAD )
# include <sched.h> # include <sched.h>
# ifdef __linux__
# include <sys/syscall.h> /* SYS_gettid */
# endif
#else
static vlc_threadvar_t cancel_key;
#endif
#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.
*/
void vlc_trace (const char *fn, const char *file, unsigned line)
{
fprintf (stderr, "at %s:%u in %s\n", file, line, fn);
fflush (stderr); /* needed before switch to low-level I/O */
#ifdef HAVE_BACKTRACE
void *stack[20];
int len = backtrace (stack, sizeof (stack) / sizeof (stack[0]));
backtrace_symbols_fd (stack, len, 2);
#endif
#ifndef WIN32
fsync (2);
#endif
}
static inline unsigned long vlc_threadid (void)
{
#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 ();
#else
return 0;
#endif
}
#ifndef NDEBUG
/*****************************************************************************
* vlc_thread_fatal: Report an error from the threading layer
*****************************************************************************
* This is mostly meant for debugging.
*****************************************************************************/
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 ());
vlc_trace (function, file, line);
/* Sometimes strerror_r() crashes too, so make sure we print an error
* message before we invoke it */
#ifdef __GLIBC__
/* Avoid the strerror_r() prototype brain damage in glibc */
errno = error;
fprintf (stderr, " Error message: %m\n");
#elif !defined (WIN32)
char buf[1000];
const char *msg;
switch (strerror_r (error, buf, sizeof (buf)))
{
case 0:
msg = buf;
break;
case ERANGE: /* should never happen */
msg = "unknwon (too big to display)";
break;
default:
msg = "unknown (invalid error number)";
break;
}
fprintf (stderr, " Error message: %s\n", msg);
#endif
fflush (stderr);
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
*/
#ifndef LIBVLC_USE_PTHREAD_CANCEL
typedef struct vlc_cancel_t
{
vlc_cleanup_t *cleaners;
bool killable;
bool killed;
# ifdef UNDER_CE
HANDLE cancel_event;
# endif
} vlc_cancel_t;
# ifndef UNDER_CE
# define VLC_CANCEL_INIT { NULL, true, false }
# else
# define VLC_CANCEL_INIT { NULL, true, false, NULL }
# endif
#endif
#ifdef UNDER_CE
static void CALLBACK vlc_cancel_self (ULONG_PTR dummy);
static DWORD vlc_cancelable_wait (DWORD count, const HANDLE *handles,
DWORD delay)
{
vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
if (nfo == NULL)
{
/* 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;
}
}
DWORD SleepEx (DWORD dwMilliseconds, BOOL bAlertable)
{
if (bAlertable)
{
DWORD result = vlc_cancelable_wait (0, NULL, dwMilliseconds);
return (result == WAIT_TIMEOUT) ? 0 : WAIT_IO_COMPLETION;
}
else
{
Sleep(dwMilliseconds);
return 0;
}
}
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 vlc_cancelable_wait (1, &hHandle, dwMilliseconds);
}
else
{
return WaitForSingleObject (hHandle, dwMilliseconds);
}
}
DWORD WaitForMultipleObjectsEx (DWORD nCount, const HANDLE *lpHandles,
BOOL bWaitAll, DWORD dwMilliseconds,
BOOL bAlertable)
{
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
#ifdef WIN32
static vlc_mutex_t super_mutex;
BOOL WINAPI DllMain (HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved)
{
(void) hinstDll;
(void) lpvReserved;
switch (fdwReason)
{
case DLL_PROCESS_ATTACH:
vlc_mutex_init (&super_mutex);
vlc_threadvar_create (&cancel_key, free);
break;
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. */
int pthread_mutexattr_setkind_np( pthread_mutexattr_t *attr, int kind );
#endif
/*****************************************************************************
* vlc_mutex_init: initialize a mutex
*****************************************************************************/
int vlc_mutex_init( vlc_mutex_t *p_mutex )
{
#if defined( LIBVLC_USE_PTHREAD )
pthread_mutexattr_t attr;
int i_result;
pthread_mutexattr_init( &attr );
# ifndef NDEBUG
/* Create error-checking mutex to detect problems more easily. */
# if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
# else
pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
# endif
# endif
i_result = pthread_mutex_init( p_mutex, &attr );
pthread_mutexattr_destroy( &attr );
return i_result;
#elif defined( WIN32 )
/* 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
}
/*****************************************************************************
* vlc_mutex_init: initialize a recursive mutex (Do not use)
*****************************************************************************/
int vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
{
#if defined( LIBVLC_USE_PTHREAD )
pthread_mutexattr_t attr;
int i_result;
pthread_mutexattr_init( &attr );
# if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_RECURSIVE_NP );
# else
pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
# endif
i_result = pthread_mutex_init( p_mutex, &attr );
pthread_mutexattr_destroy( &attr );
return( i_result );
#elif defined( WIN32 )
InitializeCriticalSection( &p_mutex->mutex );
p_mutex->initialized = 1;
return 0;
#endif
}
/**
* 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( 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
/**
* 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 )
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
}
/**
* 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 );
if (val != EBUSY)
VLC_THREAD_ASSERT ("locking mutex");
return val;
#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 variable
*****************************************************************************/
int vlc_cond_init( vlc_cond_t *p_condvar )
{
#if defined( LIBVLC_USE_PTHREAD )
pthread_condattr_t attr;
int ret;
ret = pthread_condattr_init (&attr);
if (ret)
return ret;
# if !defined (_POSIX_CLOCK_SELECTION)
/* Fairly outdated POSIX support (that was defined in 2001) */
# define _POSIX_CLOCK_SELECTION (-1)
# endif
# if (_POSIX_CLOCK_SELECTION >= 0)
/* NOTE: This must be the same clock as the one in mtime.c */
pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
# endif
ret = pthread_cond_init (p_condvar, &attr);
pthread_condattr_destroy (&attr);
return ret;
#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;
#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
}
/**
* 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 #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
{
vlc_testcancel ();
LeaveCriticalSection (&p_mutex->mutex);
result = WaitForSingleObjectEx (*p_condvar, INFINITE, TRUE);
EnterCriticalSection (&p_mutex->mutex);
}
while (result == WAIT_IO_COMPLETION);
assert (result != WAIT_ABANDONED); /* another thread failed to cleanup! */
assert (result != WAIT_FAILED);
ResetEvent (*p_condvar);
#endif
}
/**
* 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)
#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) };
int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
if (val != ETIMEDOUT)
VLC_THREAD_ASSERT ("timed-waiting on condition");
return val;
#elif defined( WIN32 )
DWORD result;
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
}
/*****************************************************************************
* vlc_tls_create: create a thread-local variable
*****************************************************************************/
int vlc_threadvar_create( vlc_threadvar_t *p_tls, void (*destr) (void *) )
{
int i_ret;
#if defined( LIBVLC_USE_PTHREAD )
i_ret = pthread_key_create( p_tls, destr );
#elif defined( WIN32 )
/* FIXME: remember/use the destr() callback and stop leaking whatever */
*p_tls = TlsAlloc();
i_ret = (*p_tls == TLS_OUT_OF_INDEXES) ? EAGAIN : 0;
#else
# error Unimplemented!
#endif
return i_ret;
}
void vlc_threadvar_delete (vlc_threadvar_t *p_tls)
{
#if defined( LIBVLC_USE_PTHREAD )
pthread_key_delete (*p_tls);
#elif defined( WIN32 )
TlsFree (*p_tls);
#else
# error Unimplemented!
#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);
self->data = self->entry (self->data);
return 0;
}
#endif
/**
* Creates and starts new thread.
*
* @param p_handle [OUT] pointer to write the handle of the created thread to
* @param entry entry point for the thread
* @param data data parameter given to the entry point
* @param priority thread priority value
* @return 0 on success, a standard error code on error.
*/
int vlc_clone (vlc_thread_t *p_handle, void * (*entry) (void *), void *data,
int priority)
{
int ret;
#if defined( LIBVLC_USE_PTHREAD )
pthread_attr_t attr;
pthread_attr_init (&attr);
/* Block the signals that signals interface plugin handles.
* If the LibVLC caller wants to handle some signals by itself, it should
* block these before whenever invoking LibVLC. And it must obviously not
* start the VLC signals interface plugin.
*
* LibVLC will normally ignore any interruption caused by an asynchronous
* signal during a system call. But there may well be some buggy cases
* where it fails to handle EINTR (bug reports welcome). Some underlying
* libraries might also not handle EINTR properly.
*/
sigset_t oldset;
{
sigset_t set;
sigemptyset (&set);
sigdelset (&set, SIGHUP);
sigaddset (&set, SIGINT);
sigaddset (&set, SIGQUIT);
sigaddset (&set, SIGTERM);
sigaddset (&set, SIGPIPE); /* We don't want this one, really! */
pthread_sigmask (SIG_BLOCK, &set, &oldset);
}
#if defined (_POSIX_PRIORITY_SCHEDULING) && (_POSIX_PRIORITY_SCHEDULING >= 0) \
&& defined (_POSIX_THREAD_PRIORITY_SCHEDULING) \
&& (_POSIX_THREAD_PRIORITY_SCHEDULING >= 0)
{
struct sched_param sp = { .sched_priority = priority, };
int policy;
if (sp.sched_priority <= 0)
sp.sched_priority += sched_get_priority_max (policy = SCHED_OTHER);
else
sp.sched_priority += sched_get_priority_min (policy = SCHED_RR);
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);
pthread_attr_destroy (&attr);
#elif defined( WIN32 ) || defined( UNDER_CE )
/* When using the MSVCRT C library you have to use the _beginthreadex
* function instead of CreateThread, otherwise you'll end up with
* memory leaks and the signal functions not working (see Microsoft
* Knowledge Base, article 104641) */
HANDLE hThread;
vlc_thread_t th = malloc (sizeof (*th));
if (th == NULL)
return ENOMEM;
th->data = data;
th->entry = entry;
#if defined( UNDER_CE )
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);
#endif
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,
GetCurrentProcess (), &th->handle, 0, FALSE,
DUPLICATE_SAME_ACCESS))
{
CloseHandle (hThread);
free (th);
return ENOMEM;
}
#else
th->handle = hThread;
#endif
ResumeThread (hThread);
if (priority)
SetThreadPriority (hThread, priority);
ret = 0;
*p_handle = th;
}
else
{
ret = errno;
free (th);
}
#endif
return ret;
}
#if defined (WIN32)
/* APC procedure for thread cancellation */
static void CALLBACK vlc_cancel_self (ULONG_PTR dummy)
{
(void)dummy;
vlc_control_cancel (VLC_DO_CANCEL);
}
#endif
/**
* Marks a thread as cancelled. Next time the target thread reaches a
* cancellation point (while not having disabled cancellation), it will
* run its cancellation cleanup handler, the thread variable destructors, and
* terminate. vlc_join() must be used afterward regardless of a thread being
* cancelled or not.
*/
void vlc_cancel (vlc_thread_t thread_id)
{
#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
# warning vlc_cancel is not implemented!
#endif
}
/**
* Waits for a thread to complete (if needed), and destroys it.
* This is a cancellation point; in case of cancellation, the join does _not_
* occur.
*
* @param handle thread handle
* @param p_result [OUT] pointer to write the thread return value or NULL
* @return 0 on success, a standard error code otherwise.
*/
void vlc_join (vlc_thread_t handle, void **result)
{
#if defined( LIBVLC_USE_PTHREAD )
int val = pthread_join (handle, result);
VLC_THREAD_ASSERT ("joining thread");
#elif defined( UNDER_CE ) || defined( WIN32 )
do
vlc_testcancel ();
while (WaitForSingleObjectEx (handle->handle, INFINITE, TRUE)
== WAIT_IO_COMPLETION);
CloseHandle (handle->handle);
if (result)
*result = handle->data;
#if defined( UNDER_CE )
CloseHandle (handle->cancel_event);
#endif
free (handle);
#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 struct vlc_thread_boot
...@@ -1248,55 +245,3 @@ void vlc_thread_cancel (vlc_object_t *obj) ...@@ -1248,55 +245,3 @@ void vlc_thread_cancel (vlc_object_t *obj)
if (priv->b_thread) if (priv->b_thread)
vlc_cancel (priv->thread_id); vlc_cancel (priv->thread_id);
} }
void vlc_control_cancel (int cmd, ...)
{
/* NOTE: This function only modifies thread-specific data, so there is no
* need to lock anything. */
#ifdef LIBVLC_USE_PTHREAD_CANCEL
(void) cmd;
assert (0);
#else
va_list ap;
vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
if (nfo == NULL)
{
#ifdef WIN32
/* Main thread - cannot be cancelled anyway */
return;
#else
nfo = malloc (sizeof (*nfo));
if (nfo == NULL)
return; /* Uho! Expect problems! */
*nfo = VLC_CANCEL_INIT;
vlc_threadvar_set (cancel_key, nfo);
#endif
}
va_start (ap, cmd);
switch (cmd)
{
case VLC_DO_CANCEL:
nfo->killed = true;
break;
case VLC_CLEANUP_PUSH:
{
/* cleaner is a pointer to the caller stack, no need to allocate
* and copy anything. As a nice side effect, this cannot fail. */
vlc_cleanup_t *cleaner = va_arg (ap, vlc_cleanup_t *);
cleaner->next = nfo->cleaners;
nfo->cleaners = cleaner;
break;
}
case VLC_CLEANUP_POP:
{
nfo->cleaners = nfo->cleaners->next;
break;
}
}
va_end (ap);
#endif
}
src/misc/w32thread.c 0 → 100644
View file @ fb671394
/*****************************************************************************
* w32thread.c : Win32 back-end for LibVLC
*****************************************************************************
* Copyright (C) 1999-2009 the VideoLAN team
* $Id$
*
* Authors: Jean-Marc Dressler <polux@via.ecp.fr>
* 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
* 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.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <vlc_common.h>
#include "libvlc.h"
#include <stdarg.h>
#include <assert.h>
static vlc_threadvar_t cancel_key;
/**
* Per-thread cancellation data
*/
typedef struct vlc_cancel_t
{
vlc_cleanup_t *cleaners;
#ifdef UNDER_CE
HANDLE cancel_event;
#endif
bool killable;
bool killed;
} vlc_cancel_t;
#ifndef UNDER_CE
# define VLC_CANCEL_INIT { NULL, true, false }
#else
# define VLC_CANCEL_INIT { NULL, NULL; true, false }
#endif
#ifdef UNDER_CE
static void CALLBACK vlc_cancel_self (ULONG_PTR dummy);
static DWORD vlc_cancelable_wait (DWORD count, const HANDLE *handles,
DWORD delay)
{
vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
if (nfo == NULL)
{
/* 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;
}
}
DWORD SleepEx (DWORD dwMilliseconds, BOOL bAlertable)
{
if (bAlertable)
{
DWORD result = vlc_cancelable_wait (0, NULL, dwMilliseconds);
return (result == WAIT_TIMEOUT) ? 0 : WAIT_IO_COMPLETION;
}
else
{
Sleep(dwMilliseconds);
return 0;
}
}
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 vlc_cancelable_wait (1, &hHandle, dwMilliseconds);
}
else
{
return WaitForSingleObject (hHandle, dwMilliseconds);
}
}
DWORD WaitForMultipleObjectsEx (DWORD nCount, const HANDLE *lpHandles,
BOOL bWaitAll, DWORD dwMilliseconds,
BOOL bAlertable)
{
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
static vlc_mutex_t super_mutex;
BOOL WINAPI DllMain (HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved)
{
(void) hinstDll;
(void) lpvReserved;
switch (fdwReason)
{
case DLL_PROCESS_ATTACH:
vlc_mutex_init (&super_mutex);
vlc_threadvar_create (&cancel_key, free);
break;
case DLL_PROCESS_DETACH:
vlc_threadvar_delete( &cancel_key );
vlc_mutex_destroy (&super_mutex);
break;
}
return TRUE;
}
/*** Mutexes ***/
int vlc_mutex_init( vlc_mutex_t *p_mutex )
{
/* 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;
}
int vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
{
InitializeCriticalSection( &p_mutex->mutex );
p_mutex->initialized = 1;
return 0;
}
void vlc_mutex_destroy (vlc_mutex_t *p_mutex)
{
assert (InterlockedExchange (&p_mutex->initialized, -1) == 1);
DeleteCriticalSection (&p_mutex->mutex);
}
void vlc_mutex_lock (vlc_mutex_t *p_mutex)
{
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);
}
int vlc_mutex_trylock (vlc_mutex_t *p_mutex)
{
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;
}
void vlc_mutex_unlock (vlc_mutex_t *p_mutex)
{
assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
LeaveCriticalSection (&p_mutex->mutex);
}
/*** Condition variables ***/
int vlc_cond_init( vlc_cond_t *p_condvar )
{
/* Create a manual-reset event (manual reset is needed for broadcast). */
*p_condvar = CreateEvent (NULL, TRUE, FALSE, NULL);
return *p_condvar ? 0 : ENOMEM;
}
void vlc_cond_destroy (vlc_cond_t *p_condvar)
{
CloseHandle (*p_condvar);
}
void vlc_cond_signal (vlc_cond_t *p_condvar)
{
/* NOTE: This will cause a broadcast, that is wrong.
* This will also wake up the next waiting thread if no threads 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);
}
void vlc_cond_broadcast (vlc_cond_t *p_condvar)
{
SetEvent (*p_condvar);
}
void vlc_cond_wait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex)
{
DWORD result;
do
{
vlc_testcancel ();
LeaveCriticalSection (&p_mutex->mutex);
result = WaitForSingleObjectEx (*p_condvar, INFINITE, TRUE);
EnterCriticalSection (&p_mutex->mutex);
}
while (result == WAIT_IO_COMPLETION);
assert (result != WAIT_ABANDONED); /* another thread failed to cleanup! */
assert (result != WAIT_FAILED);
ResetEvent (*p_condvar);
}
int vlc_cond_timedwait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
mtime_t deadline)
{
DWORD result;
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;
}
/*** Thread-specific variables (TLS) ***/
int vlc_threadvar_create (vlc_threadvar_t *p_tls, void (*destr) (void *))
{
#warning FIXME: use destr() callback and stop leaking!
*p_tls = TlsAlloc();
return (*p_tls == TLS_OUT_OF_INDEXES) ? EAGAIN : 0;
}
void vlc_threadvar_delete (vlc_threadvar_t *p_tls)
{
TlsFree (*p_tls);
}
/**
* 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)
{
return TlsSetValue (key, value) ? ENOMEM : 0;
}
/**
* 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)
{
return TlsGetValue (key);
}
/*** Threads ***/
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);
self->data = self->entry (self->data);
return 0;
}
int vlc_clone (vlc_thread_t *p_handle, void * (*entry) (void *), void *data,
int priority)
{
/* When using the MSVCRT C library you have to use the _beginthreadex
* function instead of CreateThread, otherwise you'll end up with
* memory leaks and the signal functions not working (see Microsoft
* Knowledge Base, article 104641) */
HANDLE hThread;
vlc_thread_t th = malloc (sizeof (*th));
if (th == NULL)
return ENOMEM;
th->data = data;
th->entry = entry;
#if defined( UNDER_CE )
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);
#endif
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,
GetCurrentProcess (), &th->handle, 0, FALSE,
DUPLICATE_SAME_ACCESS))
{
CloseHandle (hThread);
free (th);
return ENOMEM;
}
#else
th->handle = hThread;
#endif
ResumeThread (hThread);
if (priority)
SetThreadPriority (hThread, priority);
*p_handle = th;
return 0;
}
free (th);
return errno;
}
void vlc_join (vlc_thread_t handle, void **result)
{
do
vlc_testcancel ();
while (WaitForSingleObjectEx (handle->handle, INFINITE, TRUE)
== WAIT_IO_COMPLETION);
CloseHandle (handle->handle);
if (result)
*result = handle->data;
#ifdef UNDER_CE
CloseHandle (handle->cancel_event);
#endif
free (handle);
}
/*** Thread cancellation ***/
/* APC procedure for thread cancellation */
static void CALLBACK vlc_cancel_self (ULONG_PTR dummy)
{
(void)dummy;
vlc_control_cancel (VLC_DO_CANCEL);
}
void vlc_cancel (vlc_thread_t thread_id)
{
#ifndef UNDER_CE
QueueUserAPC (vlc_cancel_self, thread_id->handle, 0);
#else
SetEvent (thread_id->cancel_event);
#endif
}
int vlc_savecancel (void)
{
int state;
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;
return state;
}
void vlc_restorecancel (int state)
{
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;
}
void vlc_testcancel (void)
{
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);
#ifndef UNDER_CE
_endthread ();
#else
ExitThread(0);
#endif
}
}
void vlc_control_cancel (int cmd, ...)
{
/* NOTE: This function only modifies thread-specific data, so there is no
* need to lock anything. */
va_list ap;
vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
if (nfo == NULL)
return; /* Main thread - cannot be cancelled anyway */
va_start (ap, cmd);
switch (cmd)
{
case VLC_DO_CANCEL:
nfo->killed = true;
break;
case VLC_CLEANUP_PUSH:
{
/* cleaner is a pointer to the caller stack, no need to allocate
* and copy anything. As a nice side effect, this cannot fail. */
vlc_cleanup_t *cleaner = va_arg (ap, vlc_cleanup_t *);
cleaner->next = nfo->cleaners;
nfo->cleaners = cleaner;
break;
}
case VLC_CLEANUP_POP:
{
nfo->cleaners = nfo->cleaners->next;
break;
}
}
va_end (ap);
}
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