chan_console: don't read and write at the same time

It seems that the ALSA backend of PortAudio doesn't know how to both
read and write at the same time by adding a per-device mutex.

FIXME: currently only a draft version. Need to either auto-detect
we work with the ALSA backend or add an extra configuration option
to use this mutex.

ASTERISK-27426 #close

Change-Id: I635eacee45f5413faa18f5a3b606af03b926dacb

channels/chan_console.c

@@ -278,7 +278,9 @@ static void *stream_monitor(void *data)
 
 	for (;;) {
 		pthread_testcancel();
+		console_pvt_lock(pvt);
 		res = Pa_ReadStream(pvt->stream, buf, sizeof(buf) / sizeof(int16_t));
+		console_pvt_unlock(pvt);
 		pthread_testcancel();
 
 		if (!pvt->owner) {
@@ -611,7 +613,9 @@ static int console_write(struct ast_channel *chan, struct ast_frame *f)
 {
 	struct console_pvt *pvt = ast_channel_tech_pvt(chan);
 
+	console_pvt_lock(pvt);
 	Pa_WriteStream(pvt->stream, f->data.ptr, f->samples);
+	console_pvt_unlock(pvt);
 
 	return 0;
 }