GstPoll

typedef struct _GstPoll GstPoll;

A set of file/network descriptors.

GstPollFD

typedef struct {
  int fd;
} GstPollFD;

A file descriptor object.

GST_POLL_FD_INIT

#define GST_POLL_FD_INIT  { -1, -1 }

A GstPollFD must be initialized with this macro, before it can be used. This macro can used be to initialize a variable, but it cannot be assigned to a variable. In that case you have to use gst_poll_fd_init().

gst_poll_add_fd ()

gboolean            gst_poll_add_fd                     (GstPoll *set,
                                                         GstPollFD *fd);

Add a file descriptor to the file descriptor set.

gst_poll_fd_can_read ()

gboolean            gst_poll_fd_can_read                (const GstPoll *set,
                                                         GstPollFD *fd);

Check if fd in set has data to be read.

gst_poll_fd_can_write ()

gboolean            gst_poll_fd_can_write               (const GstPoll *set,
                                                         GstPollFD *fd);

Check if fd in set can be used for writing.

gst_poll_fd_ctl_read ()

gboolean            gst_poll_fd_ctl_read                (GstPoll *set,
                                                         GstPollFD *fd,
                                                         gboolean active);

Control whether the descriptor fd in set will be monitored for readability.

gst_poll_fd_ctl_write ()

gboolean            gst_poll_fd_ctl_write               (GstPoll *set,
                                                         GstPollFD *fd,
                                                         gboolean active);

Control whether the descriptor fd in set will be monitored for writability.

gst_poll_fd_has_closed ()

gboolean            gst_poll_fd_has_closed              (const GstPoll *set,
                                                         GstPollFD *fd);

Check if fd in set has closed the connection.

gst_poll_fd_has_error ()

gboolean            gst_poll_fd_has_error               (const GstPoll *set,
                                                         GstPollFD *fd);

Check if fd in set has an error.

gst_poll_fd_ignored ()

void                gst_poll_fd_ignored                 (GstPoll *set,
                                                         GstPollFD *fd);

Mark fd as ignored so that the next call to gst_poll_wait() will yield the same result for fd as last time. This function must be called if no operation (read/write/recv/send/etc.) will be performed on fd before the next call to gst_poll_wait().

The reason why this is needed is because the underlying implementation might not allow querying the fd more than once between calls to one of the re-enabling operations.

gst_poll_fd_init ()

void                gst_poll_fd_init                    (GstPollFD *fd);

Initializes fd. Alternatively you can initialize it with GST_POLL_FD_INIT.

gst_poll_free ()

void                gst_poll_free                       (GstPoll *set);

Free a file descriptor set.

gst_poll_new ()

GstPoll *           gst_poll_new                        (gboolean controllable);

Create a new file descriptor set. If controllable, it is possible to restart or flush a call to gst_poll_wait() with gst_poll_restart() and gst_poll_set_flushing() respectively.

Free-function: gst_poll_free

gst_poll_new_timer ()

GstPoll *           gst_poll_new_timer                  (void);

Create a new poll object that can be used for scheduling cancellable timeouts.

A timeout is performed with gst_poll_wait(). Multiple timeouts can be performed from different threads.

Free-function: gst_poll_free

gst_poll_get_read_gpollfd ()

void                gst_poll_get_read_gpollfd           (GstPoll *set,
                                                         GPollFD *fd);

Get a GPollFD for the reading part of the control socket. This is useful when integrating with a GSource and GMainLoop.

gst_poll_remove_fd ()

gboolean            gst_poll_remove_fd                  (GstPoll *set,
                                                         GstPollFD *fd);

Remove a file descriptor from the file descriptor set.

gst_poll_restart ()

void                gst_poll_restart                    (GstPoll *set);

Restart any gst_poll_wait() that is in progress. This function is typically used after adding or removing descriptors to set.

If set is not controllable, then this call will have no effect.

gst_poll_set_controllable ()

gboolean            gst_poll_set_controllable           (GstPoll *set,
                                                         gboolean controllable);

When controllable is TRUE, this function ensures that future calls to gst_poll_wait() will be affected by gst_poll_restart() and gst_poll_set_flushing().

gst_poll_set_flushing ()

void                gst_poll_set_flushing               (GstPoll *set,
                                                         gboolean flushing);

When flushing is TRUE, this function ensures that current and future calls to gst_poll_wait() will return -1, with errno set to EBUSY.

Unsetting the flushing state will restore normal operation of set.

gst_poll_wait ()

gint                gst_poll_wait                       (GstPoll *set,
                                                         GstClockTime timeout);

Wait for activity on the file descriptors in set. This function waits up to the specified timeout. A timeout of GST_CLOCK_TIME_NONE waits forever.

For GstPoll objects created with gst_poll_new(), this function can only be called from a single thread at a time. If called from multiple threads, -1 will be returned with errno set to EPERM.

This is not true for timer GstPoll objects created with gst_poll_new_timer(), where it is allowed to have multiple threads waiting simultaneously.

gst_poll_read_control ()

gboolean            gst_poll_read_control               (GstPoll *set);

Read a byte from the control socket of the controllable set. This function is mostly useful for timer GstPoll objects created with gst_poll_new_timer().

gst_poll_write_control ()

gboolean            gst_poll_write_control              (GstPoll *set);

Write a byte to the control socket of the controllable set. This function is mostly useful for timer GstPoll objects created with gst_poll_new_timer().

It will make any current and future gst_poll_wait() function return with 1, meaning the control socket is set. After an equal amount of calls to gst_poll_read_control() have been performed, calls to gst_poll_wait() will block again until their timeout expired.