tag_pool: use GStaticMutex

Eliminates explicit global initialisation.

src/main.c

@@ -53,7 +53,6 @@
 #include "tag.h"
 #include "zeroconf.h"
 #include "event_pipe.h"
-#include "tag_pool.h"
 #include "mpd_error.h"
 
 #ifdef ENABLE_INOTIFY
@@ -359,7 +358,6 @@ int mpd_main(int argc, char *argv[])
 	io_thread_init();
 	winsock_init();
 	idle_init();
-	tag_pool_init();
 	config_global_init();
 
 	success = parse_cmdline(argc, argv, &options, &error);
@@ -544,7 +542,6 @@ int mpd_main(int argc, char *argv[])
 	archive_plugin_deinit_all();
 #endif
 	config_global_finish();
-	tag_pool_deinit();
 	idle_deinit();
 	stats_global_finish();
 	io_thread_deinit();

src/tag.c

@@ -168,9 +168,9 @@ static void tag_delete_item(struct tag *tag, unsigned idx)
 	assert(idx < tag->num_items);
 	tag->num_items--;
 
-	g_mutex_lock(tag_pool_lock);
+	g_static_mutex_lock(&tag_pool_lock);
 	tag_pool_put_item(tag->items[idx]);
-	g_mutex_unlock(tag_pool_lock);
+	g_static_mutex_unlock(&tag_pool_lock);
 
 	if (tag->num_items - idx > 0) {
 		memmove(tag->items + idx, tag->items + idx + 1,
@@ -202,10 +202,10 @@ void tag_free(struct tag *tag)
 
 	assert(tag != NULL);
 
-	g_mutex_lock(tag_pool_lock);
+	g_static_mutex_lock(&tag_pool_lock);
 	for (i = tag->num_items; --i >= 0; )
 		tag_pool_put_item(tag->items[i]);
-	g_mutex_unlock(tag_pool_lock);
+	g_static_mutex_unlock(&tag_pool_lock);
 
 	if (tag->items == bulk.items) {
 #ifndef NDEBUG
@@ -231,10 +231,10 @@ struct tag *tag_dup(const struct tag *tag)
 	ret->num_items = tag->num_items;
 	ret->items = ret->num_items > 0 ? g_malloc(items_size(tag)) : NULL;
 
-	g_mutex_lock(tag_pool_lock);
+	g_static_mutex_lock(&tag_pool_lock);
 	for (unsigned i = 0; i < tag->num_items; i++)
 		ret->items[i] = tag_pool_dup_item(tag->items[i]);
-	g_mutex_unlock(tag_pool_lock);
+	g_static_mutex_unlock(&tag_pool_lock);
 
 	return ret;
 }
@@ -255,7 +255,7 @@ tag_merge(const struct tag *base, const struct tag *add)
 	ret->num_items = base->num_items + add->num_items;
 	ret->items = ret->num_items > 0 ? g_malloc(items_size(ret)) : NULL;
 
-	g_mutex_lock(tag_pool_lock);
+	g_static_mutex_lock(&tag_pool_lock);
 
 	/* copy all items from "add" */
 
@@ -270,7 +270,7 @@ tag_merge(const struct tag *base, const struct tag *add)
 		if (!tag_has_type(add, base->items[i]->type))
 			ret->items[n++] = tag_pool_dup_item(base->items[i]);
 
-	g_mutex_unlock(tag_pool_lock);
+	g_static_mutex_unlock(&tag_pool_lock);
 
 	assert(n <= ret->num_items);
 
@@ -502,9 +502,9 @@ tag_add_item_internal(struct tag *tag, enum tag_type type,
 		       items_size(tag) - sizeof(struct tag_item *));
 	}
 
-	g_mutex_lock(tag_pool_lock);
+	g_static_mutex_lock(&tag_pool_lock);
 	tag->items[i] = tag_pool_get_item(type, value, len);
-	g_mutex_unlock(tag_pool_lock);
+	g_static_mutex_unlock(&tag_pool_lock);
 
 	g_free(p);
 }

src/tag_pool.c

@@ -22,7 +22,17 @@
 
 #include <assert.h>
 
-GMutex *tag_pool_lock = NULL;
+#if GCC_CHECK_VERSION(4, 2)
+/* workaround for a warning caused by G_STATIC_MUTEX_INIT */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-field-initializers"
+#endif
+
+GStaticMutex tag_pool_lock = G_STATIC_MUTEX_INIT;
+
+#if GCC_CHECK_VERSION(4, 2)
+#pragma GCC diagnostic pop
+#endif
 
 #define NUM_SLOTS 4096
 
@@ -81,19 +91,6 @@ static struct slot *slot_alloc(struct slot *next,
 	return slot;
 }
 
-void tag_pool_init(void)
-{
-	g_assert(tag_pool_lock == NULL);
-	tag_pool_lock = g_mutex_new();
-}
-
-void tag_pool_deinit(void)
-{
-	g_assert(tag_pool_lock != NULL);
-	g_mutex_free(tag_pool_lock);
-	tag_pool_lock = NULL;
-}
-
 struct tag_item *
 tag_pool_get_item(enum tag_type type, const char *value, size_t length)
 {

src/tag_pool.h

@@ -24,14 +24,10 @@
 
 #include <glib.h>
 
-extern GMutex *tag_pool_lock;
+extern GStaticMutex tag_pool_lock;
 
 struct tag_item;
 
-void tag_pool_init(void);
-
-void tag_pool_deinit(void);
-
 struct tag_item *
 tag_pool_get_item(enum tag_type type, const char *value, size_t length);