perf thread_map: Add thread_map__new_event function

Introducing the thread_map__new_event function to create a struct
thread_map object from a thread_map event.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Kan Liang <kan.liang@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1445784728-21732-6-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/thread-map.c

@@ -47,10 +47,24 @@ static int process_event(struct perf_tool *tool __maybe_unused,
 			 struct machine *machine __maybe_unused)
 {
 	struct thread_map_event *map = &event->thread_map;
+	struct thread_map *threads;
 
 	TEST_ASSERT_VAL("wrong nr",   map->nr == 1);
 	TEST_ASSERT_VAL("wrong pid",  map->entries[0].pid == (u64) getpid());
 	TEST_ASSERT_VAL("wrong comm", !strcmp(map->entries[0].comm, "perf"));
+
+	threads = thread_map__new_event(&event->thread_map);
+	TEST_ASSERT_VAL("failed to alloc map", threads);
+
+	TEST_ASSERT_VAL("wrong nr", threads->nr == 1);
+	TEST_ASSERT_VAL("wrong pid",
+			thread_map__pid(threads, 0) == getpid());
+	TEST_ASSERT_VAL("wrong comm",
+			thread_map__comm(threads, 0) &&
+			!strcmp(thread_map__comm(threads, 0), "perf"));
+	TEST_ASSERT_VAL("wrong refcnt",
+			atomic_read(&threads->refcnt) == 1);
+	thread_map__put(threads);
 	return 0;
 }
 

tools/perf/util/thread_map.c

@@ -13,6 +13,7 @@
 #include "thread_map.h"
 #include "util.h"
 #include "debug.h"
+#include "event.h"
 
 /* Skip "." and ".." directories */
 static int filter(const struct dirent *dir)
@@ -409,3 +410,29 @@ void thread_map__read_comms(struct thread_map *threads)
 	for (i = 0; i < threads->nr; ++i)
 		comm_init(threads, i);
 }
+
+static void thread_map__copy_event(struct thread_map *threads,
+				   struct thread_map_event *event)
+{
+	unsigned i;
+
+	threads->nr = (int) event->nr;
+
+	for (i = 0; i < event->nr; i++) {
+		thread_map__set_pid(threads, i, (pid_t) event->entries[i].pid);
+		threads->map[i].comm = strndup(event->entries[i].comm, 16);
+	}
+
+	atomic_set(&threads->refcnt, 1);
+}
+
+struct thread_map *thread_map__new_event(struct thread_map_event *event)
+{
+	struct thread_map *threads;
+
+	threads = thread_map__alloc(event->nr);
+	if (threads)
+		thread_map__copy_event(threads, event);
+
+	return threads;
+}

tools/perf/util/thread_map.h

@@ -16,11 +16,14 @@ struct thread_map {
 	struct thread_map_data map[];
 };
 
+struct thread_map_event;
+
 struct thread_map *thread_map__new_dummy(void);
 struct thread_map *thread_map__new_by_pid(pid_t pid);
 struct thread_map *thread_map__new_by_tid(pid_t tid);
 struct thread_map *thread_map__new_by_uid(uid_t uid);
 struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid);
+struct thread_map *thread_map__new_event(struct thread_map_event *event);
 
 struct thread_map *thread_map__get(struct thread_map *map);
 void thread_map__put(struct thread_map *map);