From: Pierre-Marc Fournier <pierre-marc.fournier@polymtl.ca>
Date: Tue, 23 Mar 2010 04:16:10 +0000 (-0400)
Subject: markers/tracepoints: implement library unregistration
X-Git-Tag: v0.5~46
X-Git-Url: https://git.lttng.org/?p=ust.git;a=commitdiff_plain;h=24b6668c651f21d415b4f3a4533c7c6c6692aa73

markers/tracepoints: implement library unregistration
---

diff --git a/include/ust/marker.h b/include/ust/marker.h
index d792b65..bd1ef69 100644
--- a/include/ust/marker.h
+++ b/include/ust/marker.h
@@ -347,6 +347,7 @@ struct lib {
 };
 
 extern int marker_register_lib(struct marker *markers_start, int markers_count);
+extern int marker_unregister_lib(struct marker *markers_start);
 
 #define MARKER_LIB							\
 	extern struct marker __start___markers[] __attribute__((weak, visibility("hidden"))); \
@@ -355,6 +356,11 @@ extern int marker_register_lib(struct marker *markers_start, int markers_count);
 	static void __attribute__((constructor)) __markers__init(void)	\
 	{								\
 		marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker)); \
+	} \
+	\
+	static void __attribute__((destructor)) __markers__destroy(void)	\
+	{								\
+		marker_unregister_lib(__start___markers); \
 	}
 
 extern void marker_set_new_marker_cb(void (*cb)(struct marker *));
diff --git a/include/ust/tracepoint.h b/include/ust/tracepoint.h
index 908d5ab..6da3097 100644
--- a/include/ust/tracepoint.h
+++ b/include/ust/tracepoint.h
@@ -200,6 +200,7 @@ struct tracepoint_lib {
 
 extern int tracepoint_register_lib(struct tracepoint *tracepoints_start,
 				   int tracepoints_count);
+extern int tracepoint_unregister_lib(struct tracepoint *tracepoints_start);
 
 #define TRACEPOINT_LIB							\
 	extern struct tracepoint __start___tracepoints[] __attribute__((weak, visibility("hidden"))); \
@@ -208,6 +209,11 @@ extern int tracepoint_register_lib(struct tracepoint *tracepoints_start,
 	{								\
 		tracepoint_register_lib(__start___tracepoints,		\
 					(((long)__stop___tracepoints)-((long)__start___tracepoints))/sizeof(struct tracepoint)); \
+	} \
+	\
+	static void __attribute__((destructor)) __tracepoints__destroy(void) \
+	{								\
+		tracepoint_unregister_lib(__start___tracepoints); \
 	}
 
 #endif /* _UST_TRACEPOINT_H */
diff --git a/libust/marker.c b/libust/marker.c
index 4a3e16b..d2fee49 100644
--- a/libust/marker.c
+++ b/libust/marker.c
@@ -1383,11 +1383,28 @@ int marker_register_lib(struct marker *markers_start, int markers_count)
 	return 0;
 }
 
-int marker_unregister_lib(struct marker *markers_start, int markers_count)
+int marker_unregister_lib(struct marker *markers_start)
 {
+	struct lib *lib;
+
 	/*FIXME: implement; but before implementing, marker_register_lib must
           have appropriate locking. */
 
+	lock_markers();
+
+	/* FIXME: we should probably take a mutex here on libs */
+//ust//	mutex_lock(&module_mutex);
+	list_for_each_entry(lib, &libs, list) {
+		if(lib->markers_start == markers_start) {
+			struct lib *lib2free = lib;
+			list_del(&lib->list);
+			free(lib2free);
+			break;
+		}
+	}
+
+	unlock_markers();
+
 	return 0;
 }
 
@@ -1397,7 +1414,11 @@ void __attribute__((constructor)) init_markers(void)
 {
 	if(!initialized) {
 		marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker));
-		//DBG("markers_start: %p, markers_stop: %p\n", __start___markers, __stop___markers);
 		initialized = 1;
 	}
 }
+
+void __attribute__((constructor)) destroy_markers(void)
+{
+	marker_unregister_lib(__start___markers);
+}
diff --git a/libust/tracepoint.c b/libust/tracepoint.c
index 584b3ff..20c4767 100644
--- a/libust/tracepoint.c
+++ b/libust/tracepoint.c
@@ -678,10 +678,22 @@ int tracepoint_register_lib(struct tracepoint *tracepoints_start, int tracepoint
 	return 0;
 }
 
-int tracepoint_unregister_lib(struct tracepoint *tracepoints_start, int tracepoints_count)
+int tracepoint_unregister_lib(struct tracepoint *tracepoints_start)
 {
-	/*FIXME: implement; but before implementing, tracepoint_register_lib must
-          have appropriate locking. */
+	struct tracepoint_lib *lib;
+
+	mutex_lock(&tracepoints_mutex);
+
+	list_for_each_entry(lib, &libs, list) {
+		if(lib->tracepoints_start == tracepoints_start) {
+			struct tracepoint_lib *lib2free = lib;
+			list_del(&lib->list);
+			free(lib2free);
+			break;
+		}
+	}
+
+	mutex_unlock(&tracepoints_mutex);
 
 	return 0;
 }