output/pulse: don't expose internal struct in public header

Provide _lock() and _unlock() to wrap all accesses from the mixer
plugin.

src/mixer/pulse_mixer_plugin.c

@@ -191,13 +191,13 @@ pulse_mixer_get_volume(struct mixer *mixer, G_GNUC_UNUSED GError **error_r)
 	struct pulse_mixer *pm = (struct pulse_mixer *) mixer;
 	int ret;
 
-	pa_threaded_mainloop_lock(pm->output->mainloop);
+	pulse_output_lock(pm->output);
 
 	ret = pm->online
 		? (int)((100*(pa_cvolume_avg(&pm->volume)+1))/PA_VOLUME_NORM)
 		: -1;
 
-	pa_threaded_mainloop_unlock(pm->output->mainloop);
+	pulse_output_unlock(pm->output);
 
 	return ret;
 }
@@ -209,9 +209,10 @@ pulse_mixer_set_volume(struct mixer *mixer, unsigned volume, GError **error_r)
 	struct pa_cvolume cvolume;
 	bool success;
 
-	pa_threaded_mainloop_lock(pm->output->mainloop);
+	pulse_output_lock(pm->output);
+
 	if (!pm->online) {
-		pa_threaded_mainloop_unlock(pm->output->mainloop);
+		pulse_output_unlock(pm->output);
 		g_set_error(error_r, pulse_mixer_quark(), 0, "disconnected");
 		return false;
 	}
@@ -221,7 +222,8 @@ pulse_mixer_set_volume(struct mixer *mixer, unsigned volume, GError **error_r)
 	success = pulse_output_set_volume(pm->output, &cvolume, error_r);
 	if (success)
 		pm->volume = cvolume;
-	pa_threaded_mainloop_unlock(pm->output->mainloop);
+
+	pulse_output_unlock(pm->output);
 
 	return success;
 }

src/output/pulse_output_plugin.c

@@ -31,11 +31,42 @@
 #include <pulse/introspect.h>
 #include <pulse/subscribe.h>
 #include <pulse/error.h>
+#include <pulse/version.h>
 
 #include <assert.h>
+#include <stddef.h>
 
 #define MPD_PULSE_NAME "Music Player Daemon"
 
+#if !defined(PA_CHECK_VERSION)
+/**
+ * This macro was implemented in libpulse 0.9.16.
+ */
+#define PA_CHECK_VERSION(a,b,c) false
+#endif
+
+struct pulse_output {
+	const char *name;
+	const char *server;
+	const char *sink;
+
+	struct pulse_mixer *mixer;
+
+	struct pa_threaded_mainloop *mainloop;
+	struct pa_context *context;
+	struct pa_stream *stream;
+
+	size_t writable;
+
+#if !PA_CHECK_VERSION(0,9,11)
+	/**
+	 * We need this variable because pa_stream_is_corked() wasn't
+	 * added before 0.9.11.
+	 */
+	bool pause;
+#endif
+};
+
 /**
  * The quark used for GError.domain.
  */
@@ -45,6 +76,18 @@ pulse_output_quark(void)
 	return g_quark_from_static_string("pulse_output");
 }
 
+void
+pulse_output_lock(struct pulse_output *po)
+{
+	pa_threaded_mainloop_lock(po->mainloop);
+}
+
+void
+pulse_output_unlock(struct pulse_output *po)
+{
+	pa_threaded_mainloop_unlock(po->mainloop);
+}
+
 void
 pulse_output_set_mixer(struct pulse_output *po, struct pulse_mixer *pm)
 {

src/output/pulse_output_plugin.h

@@ -21,43 +21,18 @@
 #define MPD_PULSE_OUTPUT_PLUGIN_H
 
 #include <stdbool.h>
-#include <stddef.h>
 
 #include <glib.h>
 
-#include <pulse/version.h>
+struct pulse_output;
-
+struct pulse_mixer;
-#if !defined(PA_CHECK_VERSION)
-/**
- * This macro was implemented in libpulse 0.9.16.
- */
-#define PA_CHECK_VERSION(a,b,c) false
-#endif
-
-struct pa_operation;
 struct pa_cvolume;
 
-struct pulse_output {
+void
-	const char *name;
+pulse_output_lock(struct pulse_output *po);
-	const char *server;
-	const char *sink;
 
-	struct pulse_mixer *mixer;
+void
-
+pulse_output_unlock(struct pulse_output *po);
-	struct pa_threaded_mainloop *mainloop;
-	struct pa_context *context;
-	struct pa_stream *stream;
-
-	size_t writable;
-
-#if !PA_CHECK_VERSION(0,9,11)
-	/**
-	 * We need this variable because pa_stream_is_corked() wasn't
-	 * added before 0.9.11.
-	 */
-	bool pause;
-#endif
-};
 
 void
 pulse_output_set_mixer(struct pulse_output *po, struct pulse_mixer *pm);

test/read_mixer.c

@@ -33,6 +33,16 @@
 #ifdef HAVE_PULSE
 #include "output/pulse_output_plugin.h"
 
+void
+pulse_output_lock(G_GNUC_UNUSED struct pulse_output *po)
+{
+}
+
+void
+pulse_output_unlock(G_GNUC_UNUSED struct pulse_output *po)
+{
+}
+
 void
 pulse_output_set_mixer(G_GNUC_UNUSED struct pulse_output *po,
 		       G_GNUC_UNUSED struct pulse_mixer *pm)