*
* 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.
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
*
*/
+#define _LGPL_SOURCE
#include <errno.h>
#include <ust/tracepoint.h>
+#include <ust/tracepoint-internal.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);
+#include "usterr_signal_safe.h"
+/* libraries that contain trace_events (struct trace_event_lib) */
+static CDS_LIST_HEAD(libs);
+/*
+ * Nested mutex is not required here, but provide the same guaranteed
+ * for start/stop iteration vs nested ops as markers and tracepoints.
+ */
+static __thread int nested_mutex;
static DEFINE_MUTEX(trace_events_mutex);
+static
+int trace_event_get_iter_range(struct trace_event * const **trace_event,
+ struct trace_event * const *begin,
+ struct trace_event * const *end);
+
+static
void lock_trace_events(void)
{
- pthread_mutex_lock(&trace_events_mutex);
+ if (!(nested_mutex++))
+ pthread_mutex_lock(&trace_events_mutex);
}
+static
void unlock_trace_events(void)
{
- pthread_mutex_unlock(&trace_events_mutex);
+ if (!(--nested_mutex))
+ pthread_mutex_unlock(&trace_events_mutex);
}
-
+static
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) {
+ cds_list_for_each_entry(iter_lib, &libs, list) {
if (iter_lib < iter->lib)
continue;
else if (iter_lib > iter->lib)
*
* 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.
+ * Called with trace event mutex held.
*/
-int trace_event_get_iter_range(struct trace_event **trace_event, struct trace_event *begin,
- struct trace_event *end)
+static
+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) {
+ if (!*trace_event && begin != end)
*trace_event = begin;
- return 1;
+ while (*trace_event >= begin && *trace_event < end) {
+ if (!**trace_event)
+ (*trace_event)++; /* skip dummy */
+ else
+ return 1;
}
- if (*trace_event >= begin && *trace_event < end)
- return 1;
return 0;
}
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)
{
+ lock_trace_events();
trace_event_get_iter(iter);
}
+/*
+ * Called with trace event mutex held.
+ */
void trace_event_iter_next(struct trace_event_iter *iter)
{
iter->trace_event++;
trace_event_get_iter(iter);
}
+void trace_event_iter_stop(struct trace_event_iter *iter)
+{
+ unlock_trace_events();
+}
+
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_event_register_lib(struct trace_event * const *trace_events_start,
int trace_events_count)
{
- struct trace_event_lib *pl;
+ struct trace_event_lib *pl, *iter;
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);
+ lock_trace_events();
+ /*
+ * We sort the libs by struct lib pointer address.
+ */
+ cds_list_for_each_entry_reverse(iter, &libs, list) {
+ BUG_ON(iter == pl); /* Should never be in the list twice */
+ if (iter < pl) {
+ /* We belong to the location right after iter. */
+ cds_list_add(&pl->list, &iter->list);
+ goto lib_added;
+ }
+ }
+ /* We should be added at the head of the list */
+ cds_list_add(&pl->list, &libs);
+lib_added:
+ unlock_trace_events();
- DBG("just registered a trace_events section from %p and having %d trace_events", trace_events_start, trace_events_count);
+ /* trace_events_count - 1: skip dummy */
+ DBG("just registered a trace_events section from %p and having %d trace_events (minus dummy trace_event)", trace_events_start, trace_events_count);
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;
- pthread_mutex_lock(&trace_events_mutex);
-
- list_for_each_entry(lib, &libs, list) {
+ unlock_trace_events();
+ cds_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);
+ cds_list_del(&lib->list);
free(lib2free);
break;
}
}
-
- pthread_mutex_unlock(&trace_events_mutex);
+ unlock_trace_events();
return 0;
}
projects / ust.git / blobdiff