decoder_control: add function _is_current_song()

Replaces _current_song().

3 files changed, 42 insertions, 15 deletions

diff --git a/src/decoder_control.c b/src/decoder_control.c
index caa3705f5..2a2d8ac66 100644
--- a/src/decoder_control.c
+++ b/src/decoder_control.c
@@ -97,6 +97,27 @@ dc_command_async(struct decoder_control *dc, enum decoder_command cmd)
 	decoder_unlock(dc);
 }
 
+bool
+decoder_is_current_song(const struct decoder_control *dc,
+			const struct song *song)
+{
+	assert(dc != NULL);
+	assert(song != NULL);
+
+	switch (dc->state) {
+	case DECODE_STATE_STOP:
+	case DECODE_STATE_ERROR:
+		return false;
+
+	case DECODE_STATE_START:
+	case DECODE_STATE_DECODE:
+		return dc->song == song;
+	}
+
+	assert(false);
+	return false;
+}
+
 void
 dc_start(struct decoder_control *dc, struct song *song,
 	 unsigned start_ms, unsigned end_ms,
diff --git a/src/decoder_control.h b/src/decoder_control.h
index 743c8fb58..7305e5813 100644
--- a/src/decoder_control.h
+++ b/src/decoder_control.h
@@ -276,21 +276,27 @@ decoder_lock_has_failed(struct decoder_control *dc)
 	return ret;
 }
 
-static inline const struct song *
-decoder_current_song(const struct decoder_control *dc)
-{
-	switch (dc->state) {
-	case DECODE_STATE_STOP:
-	case DECODE_STATE_ERROR:
-		return NULL;
-
-	case DECODE_STATE_START:
-	case DECODE_STATE_DECODE:
-		return dc->song;
-	}
+/**
+ * Check if the specified song is currently being decoded.  If the
+ * decoder is not running currently (or being started), then this
+ * function returns false in any case.
+ *
+ * Caller must lock the object.
+ */
+gcc_pure
+bool
+decoder_is_current_song(const struct decoder_control *dc,
+			const struct song *song);
 
-	assert(false);
-	return NULL;
+gcc_pure
+static inline bool
+decoder_lock_is_current_song(struct decoder_control *dc,
+			     const struct song *song)
+{
+	decoder_lock(dc);
+	const bool result = decoder_is_current_song(dc, song);
+	decoder_unlock(dc);
+	return result;
 }
 
 /**
diff --git a/src/player_thread.c b/src/player_thread.c
index 486a8c96e..15fc9d235 100644
--- a/src/player_thread.c
+++ b/src/player_thread.c
@@ -458,7 +458,7 @@ static bool player_seek_decoder(struct player *player)
 
 	assert(pc->next_song != NULL);
 
-	if (decoder_current_song(dc) != song) {
+	if (!decoder_lock_is_current_song(dc, song)) {
 		/* the decoder is already decoding the "next" song -
 		   stop it and start the previous song again */