[ltt-dev] [UST PATCH 1/3] Add trace_event structs

* [ltt-dev] [UST PATCH 1/3] Add trace_event structs
@ 2010-09-09 13:06 Nils Carlson
  2010-09-09 13:06 ` [ltt-dev] [UST PATCH 2/3] Add trace_event library initialisation Nils Carlson
  2010-09-09 13:06 ` [ltt-dev] [UST PATCH 3/3] Add functions and command line for listing trace_events v2 Nils Carlson
  0 siblings, 2 replies; 5+ messages in thread
From: Nils Carlson @ 2010-09-09 13:06 UTC (permalink / raw)


Add trace_event structs, registration functions and trace_event
iterator and locking functions.

Signed-off-by: Nils Carlson <nils.carlson at ericsson.com>
---
 include/ust/tracepoint.h |   57 +++++++++++++++++
 include/ust/ust_trace.h  |   16 +++++
 libust/Makefile.am       |    1 +
 libust/trace_event.c     |  157 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 231 insertions(+), 0 deletions(-)
 create mode 100644 libust/trace_event.c

diff --git a/include/ust/tracepoint.h b/include/ust/tracepoint.h
index 9c7c091..1c4a384 100644
--- a/include/ust/tracepoint.h
+++ b/include/ust/tracepoint.h
@@ -337,6 +337,63 @@ extern int tracepoint_unregister_lib(struct tracepoint *tracepoints_start);
  * TRACE_EVENT_FN to perform any (un)registration work.
  */
 
+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;
+	int trace_events_count;
+	struct list_head list;
+};
+
+struct trace_event_iter {
+	struct trace_event_lib *lib;
+	struct trace_event *trace_event;
+};
+
+extern void lock_trace_events(void);
+extern void unlock_trace_events(void);
+
+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 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,
+				    int trace_event_count);
+
+extern int trace_event_unregister_lib(struct trace_event *start_trace_events);
+
+#define TRACE_EVENT_LIB							\
+	extern struct trace_event __start___trace_events[]		\
+	__attribute__((weak, visibility("hidden")));			\
+	extern struct trace_event __stop___trace_events[]		\
+	__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);		\
+	}								\
+									\
+	static void __attribute__((destructor))				\
+	__trace_event__destroy(void)					\
+	{								\
+		trace_event_unregister_lib(__start___trace_events);	\
+	}
+
 #define DECLARE_TRACE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
 #define DEFINE_TRACE_EVENT(template, name, proto, args)		\
 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
diff --git a/include/ust/ust_trace.h b/include/ust/ust_trace.h
index e1b0257..01c241d 100644
--- a/include/ust/ust_trace.h
+++ b/include/ust/ust_trace.h
@@ -23,6 +23,8 @@
  * to a printf
  */
 
+#include <stdio.h>
+
 /*
  * Stage 1. Create a struct and a printf calling function
  * that is connected to the tracepoint at load time.
@@ -66,6 +68,20 @@
 									\
 		printf(print);						\
 	}								\
+	static inline int register_event_##name(void *data)		\
+	{								\
+		return register_trace_##name(trace_printf_##name, data); \
+	}								\
+	static inline int unregister_event_##name(void *data)		\
+	{								\
+		return unregister_trace_##name(trace_printf_##name, data); \
+	}								\
+	struct trace_event __event_##name				\
+	__attribute__((section("__trace_events"), aligned(32)))	= {	\
+		__tpstrtab_##name,					\
+		register_event_##name,					\
+		unregister_event_##name					\
+	};								\
 	static void __attribute__((constructor)) init_##name()		\
 	{								\
 		void *dummy;						\
diff --git a/libust/Makefile.am b/libust/Makefile.am
index a6051a8..697b469 100644
--- a/libust/Makefile.am
+++ b/libust/Makefile.am
@@ -6,6 +6,7 @@ lib_LTLIBRARIES = libust.la
 libust_la_SOURCES = \
 	marker.c \
 	tracepoint.c \
+	trace_event.c \
 	channels.c \
 	channels.h \
 	marker-control.c \
diff --git a/libust/trace_event.c b/libust/trace_event.c
new file mode 100644
index 0000000..af1e3fb
--- /dev/null
+++ b/libust/trace_event.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2010 Nils Carlson
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ */
+
+#include <errno.h>
+#include <ust/tracepoint.h>
+#include <ust/core.h>
+#include <ust/kcompat/kcompat.h>
+#include "usterr.h"
+
+#define _LGPL_SOURCE
+#include <urcu-bp.h>
+
+/* libraries that contain trace_events (struct trace_event_lib) */
+static LIST_HEAD(libs);
+
+static DEFINE_MUTEX(trace_events_mutex);
+
+void lock_trace_events(void)
+{
+	pthread_mutex_lock(&trace_events_mutex);
+}
+
+void unlock_trace_events(void)
+{
+	pthread_mutex_unlock(&trace_events_mutex);
+}
+
+
+int lib_get_iter_trace_events(struct trace_event_iter *iter)
+{
+	struct trace_event_lib *iter_lib;
+	int found = 0;
+
+	list_for_each_entry(iter_lib, &libs, list) {
+		if (iter_lib < iter->lib)
+			continue;
+		else if (iter_lib > iter->lib)
+			iter->trace_event = NULL;
+		found = trace_event_get_iter_range(&iter->trace_event,
+			iter_lib->trace_events_start,
+			iter_lib->trace_events_start + iter_lib->trace_events_count);
+		if (found) {
+			iter->lib = iter_lib;
+			break;
+		}
+	}
+	return found;
+}
+
+/**
+ * trace_event_get_iter_range - Get a next trace_event iterator given a range.
+ * @trace_event: current trace_events (in), next trace_event (out)
+ * @begin: beginning of the range
+ * @end: end of the range
+ *
+ * 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)
+{
+	if (!*trace_event && begin != end) {
+		*trace_event = begin;
+		return 1;
+	}
+	if (*trace_event >= begin && *trace_event < end)
+		return 1;
+	return 0;
+}
+
+static void trace_event_get_iter(struct trace_event_iter *iter)
+{
+	int found = 0;
+
+	found = lib_get_iter_trace_events(iter);
+end:
+	if (!found)
+		trace_event_iter_reset(iter);
+}
+
+void trace_event_iter_start(struct trace_event_iter *iter)
+{
+	trace_event_get_iter(iter);
+}
+
+void trace_event_iter_next(struct trace_event_iter *iter)
+{
+	iter->trace_event++;
+	/*
+	 * iter->trace_event may be invalid because we blindly incremented it.
+	 * Make sure it is valid by marshalling on the trace_events, getting the
+	 * trace_events from following modules if necessary.
+	 */
+	trace_event_get_iter(iter);
+}
+
+void trace_event_iter_reset(struct trace_event_iter *iter)
+{
+	iter->lib = NULL;
+	iter->trace_event = NULL;
+}
+
+int trace_event_register_lib(struct trace_event *trace_events_start,
+			     int trace_events_count)
+{
+	struct trace_event_lib *pl;
+
+	pl = (struct trace_event_lib *) malloc(sizeof(struct trace_event_lib));
+
+	pl->trace_events_start = trace_events_start;
+	pl->trace_events_count = trace_events_count;
+
+	/* FIXME: maybe protect this with its own mutex? */
+	pthread_mutex_lock(&trace_events_mutex);
+	list_add(&pl->list, &libs);
+	pthread_mutex_unlock(&trace_events_mutex);
+
+	DBG("just registered a trace_events section from %p and having %d trace_events", trace_events_start, trace_events_count);
+
+	return 0;
+}
+
+int trace_event_unregister_lib(struct trace_event *trace_events_start)
+{
+	struct trace_event_lib *lib;
+
+	pthread_mutex_lock(&trace_events_mutex);
+
+	list_for_each_entry(lib, &libs, list) {
+		if(lib->trace_events_start == trace_events_start) {
+			struct trace_event_lib *lib2free = lib;
+			list_del(&lib->list);
+			free(lib2free);
+			break;
+		}
+	}
+
+	pthread_mutex_unlock(&trace_events_mutex);
+
+	return 0;
+}
-- 
1.7.1





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