From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Date: Thu, 17 Feb 2011 19:32:06 +0000 (-0500)
Subject: Trace event: export pointer array
X-Git-Tag: v1.9.1~472
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=fc1caebc8a71283c7766549ebed47300d1b52945;p=lttng-ust.git

Trace event: export pointer array

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/include/ust/tracepoint.h b/include/ust/tracepoint.h
index 05e5c11d..8be86979 100644
--- a/include/ust/tracepoint.h
+++ b/include/ust/tracepoint.h
@@ -339,17 +339,17 @@ struct trace_event {
 	const char *name;
 	int (*regfunc)(void *data);
 	int (*unregfunc)(void *data);
-} __attribute__((aligned(32)));
+};
 
 struct trace_event_lib {
-	struct trace_event *trace_events_start;
+	struct trace_event * const *trace_events_start;
 	int trace_events_count;
 	struct cds_list_head list;
 };
 
 struct trace_event_iter {
 	struct trace_event_lib *lib;
-	struct trace_event *trace_event;
+	struct trace_event * const *trace_event;
 };
 
 extern void lock_trace_events(void);
@@ -359,37 +359,35 @@ extern void trace_event_iter_start(struct trace_event_iter *iter);
 extern void trace_event_iter_next(struct trace_event_iter *iter);
 extern void trace_event_iter_reset(struct trace_event_iter *iter);
 
-extern int trace_event_get_iter_range(struct trace_event **trace_event,
-				      struct trace_event *begin,
-				      struct trace_event *end);
+extern int trace_event_get_iter_range(struct trace_event * const **trace_event,
+				      struct trace_event * const *begin,
+				      struct trace_event * const *end);
 
 extern void trace_event_update_process(void);
 extern int is_trace_event_enabled(const char *channel, const char *name);
 
-extern int trace_event_register_lib(struct trace_event *start_trace_events,
+extern int trace_event_register_lib(struct trace_event * const *start_trace_events,
 				    int trace_event_count);
 
-extern int trace_event_unregister_lib(struct trace_event *start_trace_events);
+extern int trace_event_unregister_lib(struct trace_event * const *start_trace_events);
 
 #define TRACE_EVENT_LIB							\
-	extern struct trace_event __start___trace_events[]		\
+	extern struct trace_event * const __start___trace_events_ptrs[]	\
 	__attribute__((weak, visibility("hidden")));			\
-	extern struct trace_event __stop___trace_events[]		\
+	extern struct trace_event * const __stop___trace_events_ptrs[]	\
 	__attribute__((weak, visibility("hidden")));			\
 	static void __attribute__((constructor))			\
 	__trace_events__init(void)					\
 	{								\
-		long trace_event_count =((long)__stop___trace_events-	\
-					 (long)__start___trace_events)	\
-			/sizeof(struct trace_event);			\
-		trace_event_register_lib(__start___trace_events,	\
-					 trace_event_count);		\
+		trace_event_register_lib(__start___trace_events_ptrs,	\
+					 __stop___trace_events_ptrs -	\
+					 __start___trace_events_ptrs);	\
 	}								\
 									\
 	static void __attribute__((destructor))				\
 	__trace_event__destroy(void)					\
 	{								\
-		trace_event_unregister_lib(__start___trace_events);	\
+		trace_event_unregister_lib(__start___trace_events_ptrs);\
 	}
 
 #define DECLARE_TRACE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
diff --git a/include/ust/ust_trace.h b/include/ust/ust_trace.h
index 11d5940c..66f1e878 100644
--- a/include/ust/ust_trace.h
+++ b/include/ust/ust_trace.h
@@ -76,12 +76,15 @@
 	{								\
 		return unregister_trace_##name(trace_printf_##name, data); \
 	}								\
-	struct trace_event __event_##name				\
-	__attribute__((section("__trace_events"), aligned(32)))	= {	\
+	struct trace_event __event_##name = {				\
 		__tpstrtab_##name,					\
 		register_event_##name,					\
 		unregister_event_##name					\
 	};								\
+	static struct trace_event * const __event_ptrs_##name		\
+	__attribute__((used, section("__trace_events_ptrs"))) =		\
+		&__event_##name;					\
+									\
 	static void __attribute__((constructor)) init_##name()		\
 	{								\
 		void *dummy = NULL;					\
diff --git a/libust/trace_event.c b/libust/trace_event.c
index b54d361f..d0d9ec45 100644
--- a/libust/trace_event.c
+++ b/libust/trace_event.c
@@ -72,8 +72,9 @@ int lib_get_iter_trace_events(struct trace_event_iter *iter)
  * Returns whether a next trace_event has been found (1) or not (0).
  * Will return the first trace_event in the range if the input trace_event is NULL.
  */
-int trace_event_get_iter_range(struct trace_event **trace_event, struct trace_event *begin,
-	struct trace_event *end)
+int trace_event_get_iter_range(struct trace_event * const **trace_event,
+	struct trace_event * const *begin,
+	struct trace_event * const *end)
 {
 	if (!*trace_event && begin != end) {
 		*trace_event = begin;
@@ -116,7 +117,7 @@ void trace_event_iter_reset(struct trace_event_iter *iter)
 	iter->trace_event = NULL;
 }
 
-int trace_event_register_lib(struct trace_event *trace_events_start,
+int trace_event_register_lib(struct trace_event * const *trace_events_start,
 			     int trace_events_count)
 {
 	struct trace_event_lib *pl;
@@ -136,7 +137,7 @@ int trace_event_register_lib(struct trace_event *trace_events_start,
 	return 0;
 }
 
-int trace_event_unregister_lib(struct trace_event *trace_events_start)
+int trace_event_unregister_lib(struct trace_event * const *trace_events_start)
 {
 	struct trace_event_lib *lib;
 
diff --git a/libust/tracectl.c b/libust/tracectl.c
index 233a460d..d32deba9 100644
--- a/libust/tracectl.c
+++ b/libust/tracectl.c
@@ -119,7 +119,7 @@ static void print_trace_events(FILE *fp)
 	trace_event_iter_start(&iter);
 
 	while (iter.trace_event) {
-		fprintf(fp, "trace_event: %s\n", iter.trace_event->name);
+		fprintf(fp, "trace_event: %s\n", (*iter.trace_event)->name);
 		trace_event_iter_next(&iter);
 	}
 	unlock_trace_events();