VLC 4.0.0-dev
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Modules | |
Interruptible sleep | |
Mutual exclusion locks | |
Condition variables | |
The condition variable is the most common and generic mean for threads to wait for events triggered by other threads. | |
Semaphores | |
The semaphore is the simplest thread synchronization primitive, consisting of a simple counter. | |
Latches | |
The latch is a downward counter used to synchronise threads. | |
Thread-specific variables | |
Asynchronous/threaded timers | |
Files | |
file | vlc_threads.h |
Thread primitive declarations. | |
Data Structures | |
struct | vlc_thread_t |
Thread handle. More... | |
struct | vlc_once_t |
One-time initialization. More... | |
Macros | |
#define | LIBVLC_USE_PTHREAD 1 |
Whether LibVLC threads are based on POSIX threads. | |
#define | LIBVLC_USE_PTHREAD_CLEANUP 1 |
Whether LibVLC thread cancellation is based on POSIX threads. | |
#define | VLC_THREAD_CANCELED PTHREAD_CANCELED |
Return value of a canceled thread. | |
#define | VLC_STATIC_ONCE { 0 } |
Static initializer for one-time initialization. | |
#define | vlc_once_begin(once) vlc_once_begin_inline(once) |
#define | VLC_HARD_MIN_SLEEP VLC_TICK_FROM_MS(10) /* 10 milliseconds = 1 tick at 100Hz */ |
#define | VLC_SOFT_MIN_SLEEP VLC_TICK_FROM_SEC(9) /* 9 seconds */ |
#define | vlc_cleanup_push(routine, arg) pthread_cleanup_push (routine, arg) |
Registers a thread cancellation handler. | |
#define | vlc_cleanup_pop() pthread_cleanup_pop (0) |
Unregisters the last cancellation handler. | |
#define | vlc_global_lock(n) vlc_global_mutex(n, true) |
Acquires a global mutex. | |
#define | vlc_global_unlock(n) vlc_global_mutex(n, false) |
Releases a global mutex. | |
Typedefs | |
typedef struct vlc_cleanup_t | vlc_cleanup_t |
Enumerations | |
enum | { VLC_AVCODEC_MUTEX = 0 , VLC_GCRYPT_MUTEX , VLC_XLIB_MUTEX , VLC_MOSAIC_MUTEX , VLC_MAX_MUTEX } |
Functions | |
void | vlc_testcancel (void) |
Issues an explicit deferred cancellation point. | |
bool | vlc_once_begin (vlc_once_t *restrict once) |
Begins a one-time initialization. | |
static bool | vlc_once_begin_inline (vlc_once_t *restrict once) |
void | vlc_once_complete (vlc_once_t *restrict once) |
Completes a one-time initialization. | |
static void | vlc_once (vlc_once_t *restrict once, void(*cb)(void *), void *opaque) |
Executes a function one time. | |
int | vlc_clone (vlc_thread_t *th, void *(*entry)(void *), void *data) |
Creates and starts a new thread. | |
void | vlc_thread_set_name (const char *name) |
Set the thread name of the current thread. | |
void | vlc_cancel (vlc_thread_t) |
Marks a thread as cancelled. | |
void | vlc_join (vlc_thread_t th, void **result) |
Waits for a thread to complete (if needed), then destroys it. | |
int | vlc_savecancel (void) |
Disables thread cancellation. | |
void | vlc_restorecancel (int state) |
Restores the cancellation state. | |
void | vlc_control_cancel (vlc_cleanup_t *) |
Internal handler for thread cancellation. | |
unsigned long | vlc_thread_id (void) |
Thread identifier. | |
vlc_tick_t | vlc_tick_now (void) |
Precision monotonic clock. | |
void | vlc_tick_wait (vlc_tick_t deadline) |
Waits until a deadline. | |
void | vlc_tick_sleep (vlc_tick_t delay) |
Waits for an interval of time. | |
unsigned | vlc_GetCPUCount (void) |
Count CPUs. | |
void | vlc_global_mutex (unsigned, bool) |
Internal handler for global mutexes. | |
#define LIBVLC_USE_PTHREAD 1 |
Whether LibVLC threads are based on POSIX threads.
#define LIBVLC_USE_PTHREAD_CLEANUP 1 |
Whether LibVLC thread cancellation is based on POSIX threads.
#define vlc_cleanup_pop | ( | ) | pthread_cleanup_pop (0) |
Unregisters the last cancellation handler.
This pops the cancellation handler that was last pushed with vlc_cleanup_push() in the calling thread.
Registers a thread cancellation handler.
This pushes a function to run if the thread is cancelled (or otherwise exits prematurely).
If multiple procedures are registered, they are handled in last-in first-out order.
routine | procedure to call if the thread ends |
arg | argument for the procedure |
#define vlc_global_lock | ( | n | ) | vlc_global_mutex(n, true) |
Acquires a global mutex.
#define vlc_global_unlock | ( | n | ) | vlc_global_mutex(n, false) |
Releases a global mutex.
#define VLC_HARD_MIN_SLEEP VLC_TICK_FROM_MS(10) /* 10 milliseconds = 1 tick at 100Hz */ |
#define vlc_once_begin | ( | once | ) | vlc_once_begin_inline(once) |
#define VLC_SOFT_MIN_SLEEP VLC_TICK_FROM_SEC(9) /* 9 seconds */ |
#define VLC_STATIC_ONCE { 0 } |
Static initializer for one-time initialization.
#define VLC_THREAD_CANCELED PTHREAD_CANCELED |
Return value of a canceled thread.
typedef struct vlc_cleanup_t vlc_cleanup_t |
anonymous enum |
void vlc_cancel | ( | vlc_thread_t | thread_id | ) |
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 regardless of a thread being cancelled or not, to avoid leaking resources.
References vlc_thread_t::handle, vlc_atomic_notify_one(), and vlc_cancel_self().
Referenced by Close(), httpd_HostDelete(), vlc_getaddrinfo_i11e(), vlc_h2_conn_destroy(), and vlc_h2_output_destroy().
int vlc_clone | ( | vlc_thread_t * | th, |
void *(*)(void *) | entry, | ||
void * | data | ||
) |
Creates and starts a new thread.
The thread must be joined with vlc_join() to reclaim resources when it is not needed anymore.
th | storage space for the handle of the new thread (cannot be NULL) [OUT] |
entry | entry point for the thread |
data | data parameter given to the entry point |
References vlc_thread::cancel_event, vlc_thread::cancel_sock, vlc_thread::cleaners, vlc_thread::data, vlc_thread::done_event, vlc_thread::entry, vlc_thread::id, vlc_thread::killable, vlc_thread::killed, vlc_thread::tid, unlikely, vlc_clone_attr(), and vlc_entry().
Referenced by addons_manager_Gather(), decoder_New(), httpd_HostCreate(), input_Start(), InstallEntry(), OpenSDP(), OpenURL(), sout_AnnounceRegisterSDP(), SpawnThread(), spu_Create(), TsStart(), update_Check(), update_Download(), vlc_demux_chained_New(), vlc_getaddrinfo_i11e(), vlc_h2_conn_create(), vlc_h2_output_create(), vlc_mta_acquire(), vlc_player_New(), vlc_timer_create(), vlm_New(), and vout_Request().
void vlc_control_cancel | ( | vlc_cleanup_t * | cleaner | ) |
Internal handler for thread cancellation.
Do not call this function directly. Use wrapper macros instead: vlc_cleanup_push(), vlc_cleanup_pop().
References vlc_thread::cleaners, current_thread_ctx, and vlc_assert_unreachable.
unsigned vlc_GetCPUCount | ( | void | ) |
void vlc_global_mutex | ( | unsigned | n, |
bool | acquire | ||
) |
Internal handler for global mutexes.
Do not use this function directly. Use helper macros instead: vlc_global_lock(), vlc_global_unlock().
References ARRAY_SIZE, lock, VLC_MAX_MUTEX, vlc_mutex_lock(), vlc_mutex_unlock(), and VLC_STATIC_MUTEX.
void vlc_join | ( | vlc_thread_t | th, |
void ** | result | ||
) |
Waits for a thread to complete (if needed), then destroys it.
th | thread handle |
result | [OUT] pointer to write the thread return value or NULL |
References vlc_thread_t::handle, vlc_testcancel(), VLC_THREAD_ASSERT, and vlc_WaitForSingleObject().
Referenced by addons_manager_Delete(), Close(), httpd_HostDelete(), input_Close(), sout_AnnounceUnRegister(), spu_Destroy(), TsStop(), update_Check(), update_Delete(), update_Download(), vlc_demux_chained_Delete(), vlc_executor_Delete(), vlc_getaddrinfo_i11e(), vlc_h2_conn_destroy(), vlc_h2_output_destroy(), vlc_input_decoder_Delete(), vlc_mta_release(), vlc_player_Delete(), vlc_timer_destroy(), vlm_Delete(), and vout_StopDisplay().
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inlinestatic |
Executes a function one time.
The first time this function is called with a given one-time initialization object, it executes the provided callback with the provided data pointer as sole parameter. Any further call with the same object will be a no-op.
In the corner case that the first time execution is ongoing in another thread, then the function will wait for completion on the other thread (and then synchronize memory) before it returns. This ensures that, no matter what, the callback has been executed exactly once and its side effects are visible after the function returns.
once | a one-time initialization object |
cb | callback to execute (the first time) |
opaque | data pointer for the callback |
References unlikely, vlc_once_begin, and vlc_once_complete().
bool vlc_once_begin | ( | vlc_once_t *restrict | once | ) |
Begins a one-time initialization.
This function checks if a one-time initialization has completed:
The specified one-time initialization object must have been initialized with VLC_STATIC_ONCE, which is a constant expression suitable as a static initializer.
once | one-time initialisation object |
false | on the first call (for the given object) |
true | on subsequent calls (for the given object) |
References unlikely, vlc_cond_waiter::value, vlc_atomic_wait(), VLC_ONCE_CONTEND, VLC_ONCE_DOING, VLC_ONCE_DONE, and VLC_ONCE_UNDONE.
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inlinestatic |
References unlikely, and vlc_once_begin.
void vlc_once_complete | ( | vlc_once_t *restrict | once | ) |
Completes a one-time initialization.
This function marks the end of an ongoing one-time initialization. If any thread is waiting for the completion of that initialization, its execution will be resumed.
once | one-time initialisation object |
References vlc_assert_unreachable, vlc_atomic_notify_all(), VLC_ONCE_CONTEND, VLC_ONCE_DOING, and VLC_ONCE_DONE.
Referenced by vlc_CPU_functions_init_once(), vlc_once(), and vlc_timer_create().
void vlc_restorecancel | ( | int | state | ) |
Restores the cancellation state.
This function restores the cancellation state of the calling thread to a state previously saved by vlc_savecancel().
state | previous state as returned by vlc_savecancel(). |
References current_thread_ctx, vlc_thread::killable, state, thread, unlikely, VLC_THREAD_ASSERT, and vlc_thread_fatal().
Referenced by FinderThread(), httpdLoop(), InstallerThread(), rtp_dgram_thread(), update_CheckReal(), update_DownloadReal(), vlc_h2_output_dequeue(), vlc_h2_recv_thread(), vlc_https_connect_proxy(), vlc_https_recv(), vlc_https_send(), vlc_mutex_lock(), vlc_object_deinit(), vlc_poll_i11e_inner(), vlc_poll_i11e_wake(), vlc_thread_fatal(), vlc_tls_ClientSessionCreate(), vlc_tls_ServerSessionCreate(), vlc_tls_SessionDelete(), and vlc_vaLogCallback().
int vlc_savecancel | ( | void | ) |
Disables thread cancellation.
This functions saves the current cancellation state (enabled or disabled), then disables cancellation for the calling thread. It 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.
References current_thread_ctx, vlc_thread::killable, state, thread, and VLC_THREAD_ASSERT.
Referenced by FinderThread(), httpdLoop(), InstallerThread(), rtp_dgram_thread(), update_CheckReal(), update_DownloadReal(), vlc_h2_output_dequeue(), vlc_h2_recv_thread(), vlc_https_connect_proxy(), vlc_https_recv(), vlc_https_send(), vlc_mutex_lock(), vlc_object_deinit(), vlc_poll_i11e_inner(), vlc_poll_i11e_wake(), vlc_thread_fatal(), vlc_tls_ClientSessionCreate(), vlc_tls_ServerSessionCreate(), vlc_tls_SessionDelete(), and vlc_vaLogCallback().
void vlc_testcancel | ( | void | ) |
Issues an explicit deferred cancellation point.
This has no effects 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 one (block_FifoGet() is an example).
References vlc_thread::cancel_event, vlc_thread::cleaners, current_thread_ctx, vlc_thread::data, vlc_thread::done_event, vlc_thread::killable, vlc_thread::killed, p, thread, vlc_cancel_self(), vlc_docancel(), VLC_THREAD_CANCELED, and vlc_thread_cleanup().
Referenced by net_Read(), net_Write(), vlc_atomic_timedwait(), vlc_atomic_timedwait_daytime(), vlc_atomic_wait(), vlc_fifo_Get(), vlc_frame_File(), vlc_join(), vlc_poll_i11e_inner(), vlc_queue_Dequeue(), vlc_select(), and vlc_tick_wait().
unsigned long vlc_thread_id | ( | void | ) |
Thread identifier.
This function returns a non-zero unique identifier of the calling thread. The identifier cannot change for the entire lifetime of the thread, and two concurrent threads cannot have the same identifier.
The thread identifier has no defined semantics other than uniqueness, and no particular purposes within LibVLC. It is provided mainly for tracing and debugging.
On some but not all supported platforms, the thread identifier is in fact the OS/kernel thread identifier (a.k.a. task PID), and is temporally unique not only within the process but across the entire system.
main()
thread identifier is typically identical to the process identifier, but this is not portable.References unlikely.
Referenced by vlc_mutex_held(), vlc_mutex_lock(), vlc_mutex_trylock(), vlc_queuedmutex_held(), vlc_queuedmutex_lock(), vlc_thread_fatal(), vlc_thread_fatal_print(), and vlc_vaLog().
void vlc_thread_set_name | ( | const char * | name | ) |
Set the thread name of the current thread.
name | the string to use as the thread name |
References name, and VLC_UNUSED.
Referenced by DecoderThread(), FinderThread(), httpd_HostThread(), InstallerThread(), Manage(), MtaMainLoop(), Preparse(), rtp_dgram_thread(), Run(), RunDownloader(), RunnableRun(), RunnableRun(), RunSearchLocal(), RunSearchNetwork(), RunThread(), spu_PrerenderThread(), Thread(), ThreadRun(), TsRun(), update_CheckReal(), update_DownloadReal(), vlc_demux_chained_Thread(), vlc_gai_thread(), vlc_h2_client_output_thread(), vlc_h2_output_thread(), vlc_h2_recv_thread(), vlc_player_destructor_Thread(), and vlc_timer_thread().
vlc_tick_t vlc_tick_now | ( | void | ) |
Precision monotonic clock.
In principles, the clock has a precision of 1 MHz. But the actual resolution may be much lower, especially when it comes to sleeping with vlc_tick_wait() or vlc_tick_sleep(). Most general-purpose operating systems provide a resolution of only 100 to 1000 Hz.
References freq, lldiv(), mdate_selected, Q2LL, lldiv_t::quot, lldiv_t::rem, unlikely, vlc_tick_from_samples(), vlc_tick_from_sec, and vlc_tick_from_timespec.
Referenced by ClockListenerUpdate(), CmdInitAdd(), CmdInitControl(), CmdInitDel(), CmdInitPrivControl(), CmdInitSend(), Control(), DisplayPicture(), EsOutDecodersStopBuffering(), EsOutGetBuffering(), EsOutVaControlLocked(), httpdLoop(), ImageRead(), Init(), input_rate_Add(), input_thread_Events(), MainLoop(), net_Connect(), OSDWidget(), PreparePicture(), PrerenderPicture(), RenderPicture(), rtp_dgram_thread(), rtp_queue(), rtp_timeout(), RunnableRun(), RunnableRun(), RunThread(), sout_AnnounceRegisterSDP(), sout_ClockMainSetFirstPcr(), spu_PrerenderThread(), spu_PutSubpicture(), stream_GetDelay(), stream_IsDrained(), stream_Silence(), Thread(), TraceRender(), TsStart(), UpdateCurrentPicture(), vlc_aout_stream_Drain(), vlc_aout_stream_Play(), vlc_atomic_timedwait(), vlc_atomic_timedwait(), vlc_demux_chained_Thread(), vlc_input_decoder_AddVoutOverlay(), vlc_msleep_i11e(), vlc_player_DisplayPosition(), vlc_player_GetPosition(), vlc_player_GetTime(), vlc_player_input_HandleState(), vlc_player_input_SeekByPos(), vlc_player_input_SeekByTime(), vlc_player_input_UpdateTime(), vlc_player_WaitRetryDelay(), vlc_tick_sleep(), vlc_tick_wait(), vlc_timer_schedule(), vlc_timer_thread(), vlc_tls_ClientSessionCreate(), vout_chrono_Start(), vout_chrono_Stop(), vout_display_window_MouseEvent(), vout_OSDEpg(), vout_OSDText(), vout_SetInterlacingState(), vout_snapshot_Get(), and VoutSnapshotPip().
void vlc_tick_sleep | ( | vlc_tick_t | delay | ) |
Waits for an interval of time.
delay | how long to wait (in microseconds) |
References clock_nanosleep(), vlc_tick_now(), vlc_tick_to_timespec(), and vlc_tick_wait().
Referenced by EsOutDrainDecoder(), and ModuleThread_NewSpuBuffer().
void vlc_tick_wait | ( | vlc_tick_t | deadline | ) |
Waits until a deadline.
deadline | timestamp to wait for (vlc_tick_now()) |
References clock_nanosleep(), current_thread_ctx, vlc_thread::killable, vlc_thread::killed, likely, MS_FROM_VLC_TICK, thread, unlikely, vlc_atomic_timedwait(), vlc_clock_prec, vlc_clock_setup_once(), vlc_docancel(), vlc_Sleep(), vlc_testcancel(), VLC_TICK_FROM_MS, vlc_tick_now(), and vlc_tick_to_timespec().
Referenced by vlc_mwait_i11e(), and vlc_tick_sleep().