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.
Free a file descriptor set.
Read a byte from the control socket of the controllable set.
This function only works for timer Gst.Poll objects created with
gst_poll_new_timer().
true on success. false when when there was no byte to read or reading the byte failed. If there was no byte to read, and only then, errno will contain EWOULDBLOCK or EAGAIN. For all other values of errno this always signals a critical error.
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.
This function only works for non-timer Gst.Poll objects created with
gst_poll_new().
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().
This function only works for non-timer Gst.Poll objects created with
gst_poll_new().
new controllable state.
true if the controllability of set could be updated.
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.
This function only works for non-timer Gst.Poll objects created with
gst_poll_new().
new flushing state.
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 Gst.Poll 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 Gst.Poll objects created with
gst_poll_new_timer(), where it is allowed to have multiple threads waiting
simultaneously.
a timeout in nanoseconds.
The number of Gst.PollFD in set that have activity or 0 when no activity was detected after timeout. If an error occurs, -1 is returned and errno is set.
Write a byte to the control socket of the controllable set.
This function is mostly useful for timer Gst.Poll 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.
This function only works for timer Gst.Poll objects created with
gst_poll_new_timer().
true on success. false when when the byte could not be written. errno contains the detailed error code but will never be EAGAIN, EINTR or EWOULDBLOCK. false always signals a critical error.
A Gst.Poll keeps track of file descriptors much like fd_set (used with select ()) or a struct pollfd array (used with poll ()). Once created with
gst_poll_new(), the set can be used to wait for file descriptors to be readable and/or writable. It is possible to make this wait be controlled by specifyingtruefor thecontrollableflag when creating the set (or later callinggst_poll_set_controllable()).New file descriptors are added to the set using
gst_poll_add_fd(), and removed usinggst_poll_remove_fd(). Controlling which file descriptors should be waited for to become readable and/or writable are done usinggst_poll_fd_ctl_read(),gst_poll_fd_ctl_write()andgst_poll_fd_ctl_pri().Use
gst_poll_wait()to wait for the file descriptors to actually become readable and/or writable, or to timeout if no file descriptor is available in time. The wait can be controlled by callinggst_poll_restart()andgst_poll_set_flushing().Once the file descriptor set has been waited for, one can use
gst_poll_fd_has_closed()to see if the file descriptor has been closed,gst_poll_fd_has_error()to see if it has generated an error,gst_poll_fd_can_read()to see if it is possible to read from the file descriptor, andgst_poll_fd_can_write()to see if it is possible to write to it.