Fix player thread teardown/signals on OS X

1) Realtime signals don’t exist in OS X
2) libao apparently locks a mutex in ao_play, which is locked again in
   ao_close and causes a deadlock

Closes #256, although I’m considering the option of partially reverting
7df9371491e96a99c1e463f7787aede352ac5a37, as this introduces more nasty
behavior than it solves.

3 files changed, 16 insertions, 2 deletions

diff --git a/src/player.c b/src/player.c
index b743ee8..f53feaa 100644
--- a/src/player.c
+++ b/src/player.c
@@ -156,9 +156,15 @@ static WaitressCbReturn_t BarPlayerAACCb (void *ptr, size_t size,
 			for (i = 0; i < frameInfo.samples; i++) {
 				aacDecoded[i] = applyReplayGain (aacDecoded[i], player->scale);
 			}
+
+			int oldstate;
+			pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate);
 			/* ao_play needs bytes: 1 sample = 16 bits = 2 bytes */
 			ao_play (player->audioOutDevice, (char *) aacDecoded,
 					frameInfo.samples * 2);
+			pthread_setcancelstate (PTHREAD_CANCEL_ENABLE, &oldstate);
+			pthread_testcancel();
+
 			/* add played frame length to played time, explained below */
 			player->songPlayed += (unsigned long long int) frameInfo.samples *
 					(unsigned long long int) BAR_PLAYER_MS_TO_S_FACTOR /
@@ -385,9 +391,13 @@ static WaitressCbReturn_t BarPlayerMp3Cb (void *ptr, size_t size,
 			 * be visible to user (ugly, but mp3 decoding != aac decoding) */
 			player->mode = PLAYER_RECV_DATA;
 		}
+		int oldstate;
+		pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate);
 		/* samples * length * channels */
 		ao_play (player->audioOutDevice, (char *) madDecoded,
 				player->mp3Synth.pcm.length * 2 * 2);
+		pthread_setcancelstate (PTHREAD_CANCEL_ENABLE, &oldstate);
+		pthread_testcancel();
 
 		/* avoid division by 0 */
 		if (player->mode == PLAYER_RECV_DATA) {
diff --git a/src/player.h b/src/player.h
index 2261d44..1e04f9f 100644
--- a/src/player.h
+++ b/src/player.h
@@ -47,8 +47,8 @@ THE SOFTWARE.
 
 #define BAR_PLAYER_MS_TO_S_FACTOR 1000
 #define BAR_PLAYER_BUFSIZE (WAITRESS_BUFFER_SIZE*2)
-#define BAR_PLAYER_SIGSTOP SIGRTMIN
-#define BAR_PLAYER_SIGCONT SIGRTMIN+1
+#define BAR_PLAYER_SIGSTOP SIGUSR1
+#define BAR_PLAYER_SIGCONT SIGUSR2
 
 struct audioPlayer {
 	unsigned char channels;
diff --git a/src/ui_act.c b/src/ui_act.c
index 2cc3197..a4fc1f7 100644
--- a/src/ui_act.c
+++ b/src/ui_act.c
@@ -54,6 +54,10 @@ static inline void BarUiDoSkipSong (struct audioPlayer *player) {
 	assert (player != NULL);
 
 	if (player->mode != PLAYER_FINISHED_PLAYBACK && player->mode != PLAYER_FREED) {
+		/* unpause to make sure thread is able to reach cancellation point */
+		if (player->paused) {
+			pthread_kill (player->thread, BAR_PLAYER_SIGCONT);
+		}
 		pthread_cancel (player->thread);
 	}
 }