[PATCH v3 09/17] perf dso: Use DEFINE_MUTEX for dso__data_open_lock

[Ian Rogers <irogers@google.com>]

Replace _dso__data_open_lock and its pthread_once() initialization
wrapper dso__data_open_lock() with DEFINE_MUTEX(dso__data_open_lock).

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/dso.c | 68 +++++++++++++++++--------------------------
 tools/perf/util/dso.h | 10 +++----
 2 files changed, 32 insertions(+), 46 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index cbc4f30e7f23..f0e02062c09c 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -524,25 +524,11 @@ void dso__set_module_info(struct dso *dso, struct kmod_path *m,
 /*
  * Global list of open DSOs and the counter.
  */
-struct mutex _dso__data_open_lock;
+DEFINE_MUTEX(dso__data_open_lock);
 static LIST_HEAD(dso__data_open);
-static long dso__data_open_cnt __guarded_by(&_dso__data_open_lock);
+static long dso__data_open_cnt __guarded_by(&dso__data_open_lock);
 
-static void dso__data_open_lock_init(void)
-{
-	mutex_init(&_dso__data_open_lock);
-}
-
-static struct mutex *dso__data_open_lock(void) __returns_ctx_lock(&_dso__data_open_lock)
-{
-	static pthread_once_t data_open_lock_once = PTHREAD_ONCE_INIT;
-
-	pthread_once(&data_open_lock_once, dso__data_open_lock_init);
-
-	return &_dso__data_open_lock;
-}
-
-static void dso__list_add(struct dso *dso) __must_hold(&_dso__data_open_lock)
+static void dso__list_add(struct dso *dso) __must_hold(&dso__data_open_lock)
 {
 	list_add_tail(&dso__data(dso)->open_entry, &dso__data_open);
 	/* Assume the dso is part of dsos, holding it live while on dso__data_open. */
@@ -550,7 +536,7 @@ static void dso__list_add(struct dso *dso) __must_hold(&_dso__data_open_lock)
 	dso__data_open_cnt++;
 }
 
-static void dso__list_del(struct dso_data *dso_data) __must_hold(&_dso__data_open_lock)
+static void dso__list_del(struct dso_data *dso_data) __must_hold(&dso__data_open_lock)
 {
 	list_del_init(&dso_data->open_entry);
 	WARN_ONCE(dso__data_open_cnt <= 0,
@@ -560,7 +546,7 @@ static void dso__list_del(struct dso_data *dso_data) __must_hold(&_dso__data_ope
 
 static void close_first_dso(void);
 
-static int do_open(char *name) __must_hold(&_dso__data_open_lock)
+static int do_open(char *name) __must_hold(&dso__data_open_lock)
 {
 	do {
 		int fd = open(name, O_RDONLY|O_CLOEXEC);
@@ -663,7 +649,7 @@ void dso__put_filename(struct dso *dso __maybe_unused, char *filename, bool deco
 }
 
 static int __open_dso(struct dso *dso, struct machine *machine)
-	__must_hold(&_dso__data_open_lock)
+	__must_hold(&dso__data_open_lock)
 {
 	int fd = -EINVAL;
 	char *name;
@@ -696,7 +682,7 @@ static void check_data_close(void);
  * list/count of open DSO objects.
  */
 static int open_dso(struct dso *dso, struct machine *machine)
-	__must_hold(&_dso__data_open_lock)
+	__must_hold(&dso__data_open_lock)
 {
 	int fd;
 	struct nscookie nsc;
@@ -722,7 +708,7 @@ static int open_dso(struct dso *dso, struct machine *machine)
 	return fd;
 }
 
-static void close_data_fd(struct dso_data *dso_data) __must_hold(&_dso__data_open_lock)
+static void close_data_fd(struct dso_data *dso_data) __must_hold(&dso__data_open_lock)
 {
 	if (dso_data->fd >= 0) {
 		close(dso_data->fd);
@@ -739,12 +725,12 @@ static void close_data_fd(struct dso_data *dso_data) __must_hold(&_dso__data_ope
  * Close @dso's data file descriptor and updates
  * list/count of open DSO objects.
  */
-static void close_dso(struct dso *dso) __must_hold(&_dso__data_open_lock)
+static void close_dso(struct dso *dso) __must_hold(&dso__data_open_lock)
 {
 	close_data_fd(dso__data(dso));
 }
 
-static void close_first_dso(void) __must_hold(&_dso__data_open_lock)
+static void close_first_dso(void) __must_hold(&dso__data_open_lock)
 {
 	struct dso_data *dso_data;
 
@@ -783,7 +769,7 @@ void reset_fd_limit(void)
 	fd_limit = 0;
 }
 
-static bool may_cache_fd(void) __must_hold(&_dso__data_open_lock)
+static bool may_cache_fd(void) __must_hold(&dso__data_open_lock)
 {
 	if (!fd_limit)
 		fd_limit = get_fd_limit();
@@ -799,7 +785,7 @@ static bool may_cache_fd(void) __must_hold(&_dso__data_open_lock)
  * for opened dso file descriptors. The limit is half
  * of the RLIMIT_NOFILE files opened.
 */
-static void check_data_close(void) __must_hold(&_dso__data_open_lock)
+static void check_data_close(void) __must_hold(&dso__data_open_lock)
 {
 	bool cache_fd = may_cache_fd();
 
@@ -815,9 +801,9 @@ static void check_data_close(void) __must_hold(&_dso__data_open_lock)
  */
 void dso__data_close(struct dso *dso)
 {
-	mutex_lock(dso__data_open_lock());
+	mutex_lock(&dso__data_open_lock);
 	close_dso(dso);
-	mutex_unlock(dso__data_open_lock());
+	mutex_unlock(&dso__data_open_lock);
 }
 
 static int dso__find_binary_type_locked(struct dso *dso)
@@ -913,7 +899,7 @@ static int dso__find_binary_type_locked(struct dso *dso)
 
 #define FIND_MAX_RETRY  3
 static int __dso__find_binary_type(struct dso *dso)
-	__must_hold(&_dso__data_open_lock)
+	__must_hold(&dso__data_open_lock)
 {
 	int ret;
 	int retry = 0;
@@ -945,15 +931,15 @@ enum dso_binary_type dso__find_binary_type(struct dso *dso)
 {
 	int ret;
 
-	mutex_lock(dso__data_open_lock());
+	mutex_lock(&dso__data_open_lock);
 	ret = __dso__find_binary_type(dso);
-	mutex_unlock(dso__data_open_lock());
+	mutex_unlock(&dso__data_open_lock);
 
 	return ret;
 }
 
 static void try_to_open_dso(struct dso *dso, struct machine *machine)
-	__must_hold(&_dso__data_open_lock)
+	__must_hold(&dso__data_open_lock)
 {
 	struct dso_data *dso_data = dso__data(dso);
 
@@ -984,7 +970,7 @@ bool dso__data_get_fd(struct dso *dso, struct machine *machine, int *fd)
 	if (dso__data(dso)->status == DSO_DATA_STATUS_ERROR)
 		return false;
 
-	mutex_lock(dso__data_open_lock());
+	mutex_lock(&dso__data_open_lock);
 
 	try_to_open_dso(dso, machine);
 
@@ -992,13 +978,13 @@ bool dso__data_get_fd(struct dso *dso, struct machine *machine, int *fd)
 	if (*fd >= 0)
 		return true;
 
-	mutex_unlock(dso__data_open_lock());
+	mutex_unlock(&dso__data_open_lock);
 	return false;
 }
 
 void dso__data_put_fd(struct dso *dso __maybe_unused)
 {
-	mutex_unlock(dso__data_open_lock());
+	mutex_unlock(&dso__data_open_lock);
 }
 
 bool dso__data_status_seen(struct dso *dso, enum dso_data_status_seen by)
@@ -1169,7 +1155,7 @@ static ssize_t file_read(struct dso *dso, struct machine *machine,
 {
 	ssize_t ret;
 
-	mutex_lock(dso__data_open_lock());
+	mutex_lock(&dso__data_open_lock);
 
 	/*
 	 * dso__data(dso)->fd might be closed if other thread opened another
@@ -1185,7 +1171,7 @@ static ssize_t file_read(struct dso *dso, struct machine *machine,
 
 	ret = pread(dso__data(dso)->fd, data, DSO__DATA_CACHE_SIZE, offset);
 out:
-	mutex_unlock(dso__data_open_lock());
+	mutex_unlock(&dso__data_open_lock);
 	return ret;
 }
 
@@ -1292,7 +1278,7 @@ static int file_size(struct dso *dso, struct machine *machine)
 	int ret = 0;
 	struct stat st;
 
-	mutex_lock(dso__data_open_lock());
+	mutex_lock(&dso__data_open_lock);
 
 	/*
 	 * dso__data(dso)->fd might be closed if other thread opened another
@@ -1315,7 +1301,7 @@ static int file_size(struct dso *dso, struct machine *machine)
 	dso__data(dso)->file_size = st.st_size;
 
 out:
-	mutex_unlock(dso__data_open_lock());
+	mutex_unlock(&dso__data_open_lock);
 	return ret;
 }
 
@@ -1520,7 +1506,7 @@ uint16_t dso__e_machine_endian(struct dso *dso, struct machine *machine, uint32_
 		return EM_NONE;
 	}
 
-	mutex_lock(dso__data_open_lock());
+	mutex_lock(&dso__data_open_lock);
 
 	/*
 	 * dso__data(dso)->fd might be closed if other thread opened another
@@ -1533,7 +1519,7 @@ uint16_t dso__e_machine_endian(struct dso *dso, struct machine *machine, uint32_
 	else if (e_flags)
 		*e_flags = 0;
 
-	mutex_unlock(dso__data_open_lock());
+	mutex_unlock(&dso__data_open_lock);
 	return e_machine;
 }
 
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index d6b0a1a4dac9..9f026ccb0eb6 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -354,7 +354,7 @@ DECLARE_RC_STRUCT(dso) {
 	char		 name[];
 };
 
-extern struct mutex _dso__data_open_lock;
+extern struct mutex dso__data_open_lock;
 extern const struct dso_id dso_id_empty;
 
 int dso_id__cmp(const struct dso_id *a, const struct dso_id *b);
@@ -807,7 +807,7 @@ void __dso__improve_id(struct dso *dso, const struct dso_id *id);
 int dso__name_len(const struct dso *dso);
 
 struct dso *dso__get(struct dso *dso);
-void dso__put(struct dso *dso) __must_not_hold(&_dso__data_open_lock);
+void dso__put(struct dso *dso) __must_not_hold(&dso__data_open_lock);
 
 static inline void __dso__zput(struct dso **dso)
 {
@@ -917,9 +917,9 @@ void dso__set_module_info(struct dso *dso, struct kmod_path *m,
  * TODO
 */
 bool dso__data_get_fd(struct dso *dso, struct machine *machine, int *fd)
-	__cond_acquires(true, &_dso__data_open_lock);
-void dso__data_put_fd(struct dso *dso) __releases(&_dso__data_open_lock);
-void dso__data_close(struct dso *dso) __must_not_hold(&_dso__data_open_lock);
+	__cond_acquires(true, &dso__data_open_lock);
+void dso__data_put_fd(struct dso *dso) __releases(&dso__data_open_lock);
+void dso__data_close(struct dso *dso) __must_not_hold(&dso__data_open_lock);
 
 int dso__data_file_size(struct dso *dso, struct machine *machine);
 off_t dso__data_size(struct dso *dso, struct machine *machine);
-- 
2.56.0.212.g129ede20d9-goog