udp: fix non-blocking and interrupt handling.

In non-blocking mode, lowest-level read protocols are
supposed block only for a short amount of time to let
retry_transfer_wrapper() check for interrupts.

Also, checking the interrupt_callback in the receiving thread is
wrong, as interrupt_callback is not guaranteed to be thread-safe
and the job is already done by retry_transfer_wrapper(). The error
code was also incorrect.

Bug reported by Andrey Utkin.
This commit is contained in:
Nicolas George 2012-03-15 12:19:37 +01:00
parent d9f26a0d71
commit 463705bd1c

View File

@ -336,11 +336,6 @@ static void *circular_buffer_task( void *_URLContext)
int ret;
int len;
if (ff_check_interrupt(&h->interrupt_callback)) {
s->circular_buffer_error = AVERROR(EINTR);
goto end;
}
FD_ZERO(&rfds);
FD_SET(s->udp_fd, &rfds);
tv.tv_sec = 1;
@ -590,7 +585,7 @@ static int udp_read(URLContext *h, uint8_t *buf, int size)
{
UDPContext *s = h->priv_data;
int ret;
int avail;
int avail, nonblock = h->flags & AVIO_FLAG_NONBLOCK;
#if HAVE_PTHREADS
if (s->fifo) {
@ -614,12 +609,19 @@ static int udp_read(URLContext *h, uint8_t *buf, int size)
} else if(s->circular_buffer_error){
pthread_mutex_unlock(&s->mutex);
return s->circular_buffer_error;
} else if(h->flags & AVIO_FLAG_NONBLOCK) {
} else if(nonblock) {
pthread_mutex_unlock(&s->mutex);
return AVERROR(EAGAIN);
}
else {
pthread_cond_wait(&s->cond, &s->mutex);
/* FIXME: using the monotonic clock would be better,
but it does not exist on all supported platforms. */
int64_t t = av_gettime() + 100000;
struct timespec tv = { .tv_sec = t / 1000000,
.tv_nsec = (t % 1000000) * 1000 };
if (pthread_cond_timedwait(&s->cond, &s->mutex, &tv) < 0)
return AVERROR(errno == ETIMEDOUT ? EAGAIN : errno);
nonblock = 1;
}
} while( 1);
}