This patch begins tranformation of libtraceevent into a
thread safe library. It implements per thread local storage
of tep hadler thread sensitive data and internal
APIs to access it. It covers tep->last_event cache,
more library's thread sensitive data will be added with
additional patches.
Signed-off-by: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
---
lib/traceevent/Makefile | 1 +
lib/traceevent/event-parse-local.h | 15 +++++--
lib/traceevent/event-parse-thread.c | 63 +++++++++++++++++++++++++++++
lib/traceevent/event-parse.c | 39 +++++++++---------
4 files changed, 97 insertions(+), 21 deletions(-)
create mode 100644 lib/traceevent/event-parse-thread.c
diff --git a/lib/traceevent/Makefile b/lib/traceevent/Makefile
index bfbb6a3..8e34a97 100644
--- a/lib/traceevent/Makefile
+++ b/lib/traceevent/Makefile
@@ -14,6 +14,7 @@ OBJS += trace-seq.o
OBJS += parse-filter.o
OBJS += parse-utils.o
OBJS += event-parse-api.o
+OBJS += event-parse-thread.o
# Additional util objects
OBJS += str_error_r.o
diff --git a/lib/traceevent/event-parse-local.h b/lib/traceevent/event-parse-local.h
index 70693b8..2c75f9e 100644
--- a/lib/traceevent/event-parse-local.h
+++ b/lib/traceevent/event-parse-local.h
@@ -14,6 +14,12 @@ struct func_list;
struct event_handler;
struct func_resolver;
+/* cache */
+struct tep_thread_data {
+ struct tep_handle *tep;
+ struct tep_event *last_event;
+};
+
struct tep_handle {
int ref_count;
@@ -85,9 +91,6 @@ struct tep_handle {
int parsing_failures;
- /* cache */
- struct tep_event *last_event;
-
char *trace_clock;
};
@@ -98,4 +101,10 @@ unsigned short tep_data2host2(struct tep_handle *pevent, unsigned short data);
unsigned int tep_data2host4(struct tep_handle *pevent, unsigned int data);
unsigned long long tep_data2host8(struct tep_handle *pevent, unsigned long long data);
+/* tep cache per thread */
+struct tep_event *get_thread_local_event_by_id(struct tep_handle *tep, int id);
+struct tep_event *
+get_thread_local_event_by_name(struct tep_handle *tep, const char *name, const char *sys);
+void set_thread_local_event_cache(struct tep_handle *tep, struct tep_event *event);
+
#endif /* _PARSE_EVENTS_INT_H */
diff --git a/lib/traceevent/event-parse-thread.c b/lib/traceevent/event-parse-thread.c
new file mode 100644
index 0000000..f846350
--- /dev/null
+++ b/lib/traceevent/event-parse-thread.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@xxxxxxxxxx>
+ *
+ */
+
+#include "event-parse.h"
+#include "event-parse-local.h"
+#include "event-utils.h"
+
+static __thread struct tep_thread_data tep_thread_local;
+
+/**
+ * get_thread_local_event_by_id - Find event with given id in the cache
+ * @tep: a handle to the tep context
+ * @id: event's id
+ *
+ * Searches in the cache for event with given id
+ */
+struct tep_event *get_thread_local_event_by_id(struct tep_handle *tep, int id)
+{
+
+ if (tep_thread_local.last_event && tep_thread_local.tep == tep &&
+ tep_thread_local.last_event->id == id)
+ return tep_thread_local.last_event;
+
+ return NULL;
+}
+
+/**
+ * get_thread_local_event_by_name - Find event with given name and sys in the cache
+ * @tep: a handle to the tep context
+ * @name: event's name
+ * @sys: event's system
+ *
+ * Searches in the cache for event with given name and system
+ */
+struct tep_event *
+get_thread_local_event_by_name(struct tep_handle *tep, const char *name, const char *sys)
+{
+ if (tep_thread_local.last_event &&
+ tep_thread_local.tep == tep &&
+ strcmp(tep_thread_local.last_event->name, name) == 0 &&
+ (!sys || strcmp(tep_thread_local.last_event->system, sys) == 0))
+ return tep_thread_local.last_event;
+
+ return NULL;
+}
+
+/**
+ * set_thread_local_event_cache - set last used event in the cache
+ * @tep: a handle to the tep context
+ * @event: pointer to the last used event
+ *
+ * Sets last used event in the cache, to speed up the next searches
+ */
+void set_thread_local_event_cache(struct tep_handle *tep, struct tep_event *event)
+{
+ tep_thread_local.tep = tep;
+ tep_thread_local.last_event = event;
+}
+
+
diff --git a/lib/traceevent/event-parse.c b/lib/traceevent/event-parse.c
index bc35dc8..cacdcc4 100644
--- a/lib/traceevent/event-parse.c
+++ b/lib/traceevent/event-parse.c
@@ -3461,28 +3461,29 @@ static int events_id_cmp(const void *a, const void *b);
/**
* tep_find_event - find an event by given id
- * @pevent: a handle to the pevent
+ * @tep: a handle to the tep context
* @id: the id of the event
*
* Returns an event that has a given @id.
*/
-struct tep_event *tep_find_event(struct tep_handle *pevent, int id)
+struct tep_event *tep_find_event(struct tep_handle *tep, int id)
{
struct tep_event **eventptr;
struct tep_event key;
struct tep_event *pkey = &key;
+ struct tep_event *event_cache = get_thread_local_event_by_id(tep, id);
/* Check cache first */
- if (pevent->last_event && pevent->last_event->id == id)
- return pevent->last_event;
+ if (event_cache)
+ return event_cache;
key.id = id;
- eventptr = bsearch(&pkey, pevent->events, pevent->nr_events,
- sizeof(*pevent->events), events_id_cmp);
+ eventptr = bsearch(&pkey, tep->events, tep->nr_events,
+ sizeof(*tep->events), events_id_cmp);
if (eventptr) {
- pevent->last_event = *eventptr;
+ set_thread_local_event_cache(tep, *eventptr);
return *eventptr;
}
@@ -3491,7 +3492,7 @@ struct tep_event *tep_find_event(struct tep_handle *pevent, int id)
/**
* tep_find_event_by_name - find an event by given name
- * @pevent: a handle to the pevent
+ * @tep: a handle to the tep context
* @sys: the system name to search for
* @name: the name of the event to search for
*
@@ -3499,19 +3500,19 @@ struct tep_event *tep_find_event(struct tep_handle *pevent, int id)
* @sys. If @sys is NULL the first event with @name is returned.
*/
struct tep_event *
-tep_find_event_by_name(struct tep_handle *pevent,
+tep_find_event_by_name(struct tep_handle *tep,
const char *sys, const char *name)
{
- struct tep_event *event;
int i;
+ struct tep_event *event = NULL;
+ struct tep_event *event_cache = get_thread_local_event_by_name(tep, name, sys);
- if (pevent->last_event &&
- strcmp(pevent->last_event->name, name) == 0 &&
- (!sys || strcmp(pevent->last_event->system, sys) == 0))
- return pevent->last_event;
+ /* Check cache first */
+ if (event_cache)
+ return event_cache;
- for (i = 0; i < pevent->nr_events; i++) {
- event = pevent->events[i];
+ for (i = 0; i < tep->nr_events; i++) {
+ event = tep->events[i];
if (strcmp(event->name, name) == 0) {
if (!sys)
break;
@@ -3519,10 +3520,12 @@ tep_find_event_by_name(struct tep_handle *pevent,
break;
}
}
- if (i == pevent->nr_events)
+
+ if (i == tep->nr_events)
event = NULL;
+ if (event)
+ set_thread_local_event_cache(tep, event);
- pevent->last_event = event;
return event;
}
--
2.19.2
|