perf tools: Refactor all_tids to hold nr and the map

So that later, we can pass the thread_map instance instead of
(thread_num, thread_map) for things like perf_evsel__open and friends,
just like was done with cpu_map.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 43 insertions, 15 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 8c72d888e449..00f4eade2e3e 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -16,35 +16,50 @@ static int filter(const struct dirent *dir)
                 return 1;
 }
 
-int find_all_tid(int pid, pid_t ** all_tid)
+struct thread_map *thread_map__new_by_pid(pid_t pid)
 {
+        struct thread_map *threads;
         char name[256];
         int items;
         struct dirent **namelist = NULL;
-        int ret = 0;
         int i;
 
         sprintf(name, "/proc/%d/task", pid);
         items = scandir(name, &namelist, filter, NULL);
         if (items <= 0)
-                return -ENOENT;
-        *all_tid = malloc(sizeof(pid_t) * items);
-        if (!*all_tid) {
-                ret = -ENOMEM;
-                goto failure;
-        }
-
-        for (i = 0; i < items; i++)
-                (*all_tid)[i] = atoi(namelist[i]->d_name);
+                return NULL;
 
-        ret = items;
+        threads = malloc(sizeof(*threads) + sizeof(pid_t) * items);
+        if (threads != NULL) {
+                for (i = 0; i < items; i++)
+                        threads->map[i] = atoi(namelist[i]->d_name);
+                threads->nr = items;
+        }
 
-failure:
         for (i=0; i<items; i++)
                 free(namelist[i]);
         free(namelist);
 
-        return ret;
+        return threads;
+}
+
+struct thread_map *thread_map__new_by_tid(pid_t tid)
+{
+        struct thread_map *threads = malloc(sizeof(*threads) + sizeof(pid_t));
+
+        if (threads != NULL) {
+                threads->map[0] = tid;
+                threads->nr     = 1;
+        }
+
+        return threads;
+}
+
+struct thread_map *thread_map__new(pid_t pid, pid_t tid)
+{
+        if (pid != -1)
+                return thread_map__new_by_pid(pid);
+        return thread_map__new_by_tid(tid);
 }
 
 static struct thread *thread__new(pid_t pid)
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 688500ff826f..d7574101054a 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -18,11 +18,24 @@ struct thread {
         int                     comm_len;
 };
 
+struct thread_map {
+        int nr;
+        int map[];
+};
+
 struct perf_session;
 
 void thread__delete(struct thread *self);
 
-int find_all_tid(int pid, pid_t ** all_tid);
+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(pid_t pid, pid_t tid);
+
+static inline void thread_map__delete(struct thread_map *threads)
+{
+        free(threads);
+}
+
 int thread__set_comm(struct thread *self, const char *comm);
 int thread__comm_len(struct thread *self);
 struct thread *perf_session__findnew(struct perf_session *self, pid_t pid);