rtems_status_code
rtems_termios_read (void *arg)
{
rtems_libio_rw_args_t *args = arg;
struct rtems_termios_tty *tty = args->iop->data1;
uint32_t count = args->count;
char *buffer = args->buffer;
rtems_status_code sc;
sc = rtems_semaphore_obtain (tty->isem, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
if (sc != RTEMS_SUCCESSFUL)
return sc;
if (rtems_termios_linesw[tty->t_line].l_read != NULL) {
sc = rtems_termios_linesw[tty->t_line].l_read(tty,args);
tty->tty_rcvwakeup = 0;
rtems_semaphore_release (tty->isem);
return sc;
}
if (tty->cindex == tty->ccount) {
tty->cindex = tty->ccount = 0;
tty->read_start_column = tty->column;
if (tty->device.pollRead != NULL &&
tty->device.outputUsesInterrupts == TERMIOS_POLLED)
sc = fillBufferPoll (tty);
else
sc = fillBufferQueue (tty);
if (sc != RTEMS_SUCCESSFUL)
tty->cindex = tty->ccount = 0;
}
while (count && (tty->cindex < tty->ccount)) {
*buffer++ = tty->cbuf[tty->cindex++];
count--;
}
args->bytes_moved = args->count - count;
tty->tty_rcvwakeup = 0;
rtems_semaphore_release (tty->isem);
return sc;
}
/* A method run in a backround thread, to keep filling the queue with new
* audio over time.
*/
void backgroundProc()
{
/* Temporary storage to read samples into, before passing to OpenAL.
* Kept here to avoid reallocating it during playback.
*/
std::vector<char> buffer(sBufferFrames * mFrameSize);
while (!mQuit.load())
{
/* First, make sure the buffer queue is filled. */
fillBufferQueue(buffer);
ALint state;
alGetSourcei(mSource, AL_SOURCE_STATE, &state);
if (state != AL_PLAYING && state != AL_PAUSED)
{
/* If the source is not playing or paused, it either underrun
* or hasn't started at all yet. So remove any buffers that
* have been played (will be 0 when first starting).
*/
ALint processed;
alGetSourcei(mSource, AL_BUFFERS_PROCESSED, &processed);
while (processed > 0)
{
ALuint bufid;
alSourceUnqueueBuffers(mSource, 1, &bufid);
--processed;
}
/* Make sure the buffer queue is still filled, in case another
* buffer had finished before checking the state and after the
* last fill. If the queue is empty, playback is over.
*/
if (fillBufferQueue(buffer) == 0)
{
mQuit.store(true);
return;
}
/* Now start the sound source. */
alSourcePlay(mSource);
}
ALint processed;
alGetSourcei(mSource, AL_BUFFERS_PROCESSED, &processed);
if (processed == 0)
{
/* Wait until a buffer in the queue has been processed. */
do {
std::this_thread::sleep_for(std::chrono::milliseconds(50));
if (mQuit.load()) break;
alGetSourcei(mSource, AL_BUFFERS_PROCESSED, &processed);
} while (processed == 0);
}
/* Remove processed buffers, then restart the loop to keep the
* queue filled.
*/
while (processed > 0)
{
ALuint bufid;
alSourceUnqueueBuffers(mSource, 1, &bufid);
--processed;
}
}
}
