Add trace_event structs

[ust.git] / libust / trace_event.c

diff --git a/libust/trace_event.c b/libust/trace_event.c
new file mode 100644 (file)
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;
+}