perf tools: Add reference counting for thread_map object

Adding reference counting for thread_map object, so it could be easily
shared among other objects.

Using thread_map__put instead thread_map__delete and making
thread_map__delete static.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1435012588-9007-5-git-send-email-jolsa@kernel.org
[ Adjustments to move it ahead of the "comm" patches ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

11 files changed, 43 insertions, 14 deletions

diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index 6b3250f54240..39c784a100a9 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -546,7 +546,7 @@ out_err:
                 perf_evlist__delete(evlist);
         } else {
                 cpu_map__put(cpus);
-                thread_map__delete(threads);
+                thread_map__put(threads);
         }
         machines__destroy_kernel_maps(&machines);
         machine__delete_threads(machine);
diff --git a/tools/perf/tests/keep-tracking.c b/tools/perf/tests/keep-tracking.c
index a330235cefc0..4d4b9837b630 100644
--- a/tools/perf/tests/keep-tracking.c
+++ b/tools/perf/tests/keep-tracking.c
@@ -145,7 +145,7 @@ out_err:
                 perf_evlist__delete(evlist);
         } else {
                 cpu_map__put(cpus);
-                thread_map__delete(threads);
+                thread_map__put(threads);
         }
 
         return err;
diff --git a/tools/perf/tests/mmap-basic.c b/tools/perf/tests/mmap-basic.c
index 5a9ef5833452..666b67a4df9d 100644
--- a/tools/perf/tests/mmap-basic.c
+++ b/tools/perf/tests/mmap-basic.c
@@ -142,6 +142,6 @@ out_delete_evlist:
 out_free_cpus:
         cpu_map__put(cpus);
 out_free_threads:
-        thread_map__delete(threads);
+        thread_map__put(threads);
         return err;
 }
diff --git a/tools/perf/tests/mmap-thread-lookup.c b/tools/perf/tests/mmap-thread-lookup.c
index 7f48efa7e295..145050e2e544 100644
--- a/tools/perf/tests/mmap-thread-lookup.c
+++ b/tools/perf/tests/mmap-thread-lookup.c
@@ -143,7 +143,7 @@ static int synth_process(struct machine *machine)
                                                 perf_event__process,
                                                 machine, 0, 500);
 
-        thread_map__delete(map);
+        thread_map__put(map);
         return err;
 }
 
diff --git a/tools/perf/tests/openat-syscall-all-cpus.c b/tools/perf/tests/openat-syscall-all-cpus.c
index 9a7a116e09b8..b8d552b13950 100644
--- a/tools/perf/tests/openat-syscall-all-cpus.c
+++ b/tools/perf/tests/openat-syscall-all-cpus.c
@@ -111,6 +111,6 @@ out_close_fd:
 out_evsel_delete:
         perf_evsel__delete(evsel);
 out_thread_map_delete:
-        thread_map__delete(threads);
+        thread_map__put(threads);
         return err;
 }
diff --git a/tools/perf/tests/openat-syscall.c b/tools/perf/tests/openat-syscall.c
index 9f9491bb8e48..bdfa1f446681 100644
--- a/tools/perf/tests/openat-syscall.c
+++ b/tools/perf/tests/openat-syscall.c
@@ -56,6 +56,6 @@ out_close_fd:
 out_evsel_delete:
         perf_evsel__delete(evsel);
 out_thread_map_delete:
-        thread_map__delete(threads);
+        thread_map__put(threads);
         return err;
 }
diff --git a/tools/perf/tests/switch-tracking.c b/tools/perf/tests/switch-tracking.c
index 1b06122beb76..e698742d4fec 100644
--- a/tools/perf/tests/switch-tracking.c
+++ b/tools/perf/tests/switch-tracking.c
@@ -561,7 +561,7 @@ out:
                 perf_evlist__delete(evlist);
         } else {
                 cpu_map__put(cpus);
-                thread_map__delete(threads);
+                thread_map__put(threads);
         }
 
         return err;
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 59498f7b3e9b..a8d18a3d2164 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -115,7 +115,7 @@ void perf_evlist__delete(struct perf_evlist *evlist)
         perf_evlist__munmap(evlist);
         perf_evlist__close(evlist);
         cpu_map__put(evlist->cpus);
-        thread_map__delete(evlist->threads);
+        thread_map__put(evlist->threads);
         evlist->cpus = NULL;
         evlist->threads = NULL;
         perf_evlist__purge(evlist);
@@ -1120,7 +1120,7 @@ int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
         return 0;
 
 out_delete_threads:
-        thread_map__delete(evlist->threads);
+        thread_map__put(evlist->threads);
         evlist->threads = NULL;
         return -1;
 }
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index b106d56df240..626422eda727 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -453,7 +453,7 @@ static int pyrf_thread_map__init(struct pyrf_thread_map *pthreads,
 
 static void pyrf_thread_map__delete(struct pyrf_thread_map *pthreads)
 {
-        thread_map__delete(pthreads->threads);
+        thread_map__put(pthreads->threads);
         pthreads->ob_type->tp_free((PyObject*)pthreads);
 }
 
diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
index 920136dd8c2e..368cc58c6892 100644
--- a/tools/perf/util/thread_map.c
+++ b/tools/perf/util/thread_map.c
@@ -8,6 +8,7 @@
 #include <unistd.h>
 #include "strlist.h"
 #include <string.h>
+#include "asm/bug.h"
 #include "thread_map.h"
 #include "util.h"
 
@@ -47,6 +48,7 @@ struct thread_map *thread_map__new_by_pid(pid_t pid)
                 for (i = 0; i < items; i++)
                         thread_map__set_pid(threads, i, atoi(namelist[i]->d_name));
                 threads->nr = items;
+                atomic_set(&threads->refcnt, 1);
         }
 
         for (i=0; i<items; i++)
@@ -63,6 +65,7 @@ struct thread_map *thread_map__new_by_tid(pid_t tid)
         if (threads != NULL) {
                 thread_map__set_pid(threads, 0, tid);
                 threads->nr = 1;
+                atomic_set(&threads->refcnt, 1);
         }
 
         return threads;
@@ -84,6 +87,7 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
                 goto out_free_threads;
 
         threads->nr = 0;
+        atomic_set(&threads->refcnt, 1);
 
         while (!readdir_r(proc, &dirent, &next) && next) {
                 char *end;
@@ -212,6 +216,8 @@ static struct thread_map *thread_map__new_by_pid_str(const char *pid_str)
 
 out:
         strlist__delete(slist);
+        if (threads)
+                atomic_set(&threads->refcnt, 1);
         return threads;
 
 out_free_namelist:
@@ -231,6 +237,7 @@ struct thread_map *thread_map__new_dummy(void)
         if (threads != NULL) {
                 thread_map__set_pid(threads, 0, -1);
                 threads->nr = 1;
+                atomic_set(&threads->refcnt, 1);
         }
         return threads;
 }
@@ -273,6 +280,8 @@ static struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
                 threads->nr = ntasks;
         }
 out:
+        if (threads)
+                atomic_set(&threads->refcnt, 1);
         return threads;
 
 out_free_threads:
@@ -292,9 +301,26 @@ struct thread_map *thread_map__new_str(const char *pid, const char *tid,
         return thread_map__new_by_tid_str(tid);
 }
 
-void thread_map__delete(struct thread_map *threads)
+static void thread_map__delete(struct thread_map *threads)
 {
-        free(threads);
+        if (threads) {
+                WARN_ONCE(atomic_read(&threads->refcnt) != 0,
+                          "thread map refcnt unbalanced\n");
+                free(threads);
+        }
+}
+
+struct thread_map *thread_map__get(struct thread_map *map)
+{
+        if (map)
+                atomic_inc(&map->refcnt);
+        return map;
+}
+
+void thread_map__put(struct thread_map *map)
+{
+        if (map && atomic_dec_and_test(&map->refcnt))
+                thread_map__delete(map);
 }
 
 size_t thread_map__fprintf(struct thread_map *threads, FILE *fp)
diff --git a/tools/perf/util/thread_map.h b/tools/perf/util/thread_map.h
index b9f40679f589..6b0cd2dc006b 100644
--- a/tools/perf/util/thread_map.h
+++ b/tools/perf/util/thread_map.h
@@ -3,12 +3,14 @@
 
 #include <sys/types.h>
 #include <stdio.h>
+#include <linux/atomic.h>
 
 struct thread_map_data {
         pid_t    pid;
 };
 
 struct thread_map {
+        atomic_t refcnt;
         int nr;
         struct thread_map_data map[];
 };
@@ -19,11 +21,12 @@ 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__get(struct thread_map *map);
+void thread_map__put(struct thread_map *map);
+
 struct thread_map *thread_map__new_str(const char *pid,
                 const char *tid, uid_t uid);
 
-void thread_map__delete(struct thread_map *threads);
-
 size_t thread_map__fprintf(struct thread_map *threads, FILE *fp);
 
 static inline int thread_map__nr(struct thread_map *threads)