[PATCH v1 1/4] perf mutex: Wrapped usage of pthread_mutex_t

From: gpavithrasha
Date: Wed Jul 27 2022 - 07:20:29 EST


From: pavithra <gpavithrasha@xxxxxxxxx>

Added a new header file mutex.h that wraps the
usage of pthread_mutex_t and updated lock in dso.h.

Signed-off-by: pavithra <gpavithrasha@xxxxxxxxx>
---
tools/perf/util/Build | 1 +
tools/perf/util/dso.c | 33 ++++++++++++++++-----------------
tools/perf/util/dso.h | 3 ++-
tools/perf/util/mutex.c | 32 ++++++++++++++++++++++++++++++++
tools/perf/util/mutex.h | 15 +++++++++++++++
tools/perf/util/symbol.c | 4 ++--
6 files changed, 68 insertions(+), 20 deletions(-)
create mode 100644 tools/perf/util/mutex.c
create mode 100644 tools/perf/util/mutex.h

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 8dcfca1a882f..559c20d94c36 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -120,6 +120,7 @@ perf-y += time-utils.o
perf-y += expr-bison.o
perf-y += branch.o
perf-y += mem2node.o
+perf-y += mutex.o

perf-$(CONFIG_LIBBPF) += bpf-loader.o
perf-$(CONFIG_LIBBPF) += bpf_map.o
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index e11ddf86f2b3..605c31585d48 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -426,7 +426,7 @@ void dso__set_module_info(struct dso *dso, struct kmod_path *m,
*/
static LIST_HEAD(dso__data_open);
static long dso__data_open_cnt;
-static pthread_mutex_t dso__data_open_lock = PTHREAD_MUTEX_INITIALIZER;
+static struct mutex dso__data_open_lock = PTHREAD_MUTEX_INITIALIZER;

static void dso__list_add(struct dso *dso)
{
@@ -633,9 +633,9 @@ static void check_data_close(void)
*/
void dso__data_close(struct dso *dso)
{
- pthread_mutex_lock(&dso__data_open_lock);
+ mutex_lock(&dso__data_open_lock);
close_dso(dso);
- pthread_mutex_unlock(&dso__data_open_lock);
+ mutex_unlock(&dso__data_open_lock);
}

static void try_to_open_dso(struct dso *dso, struct machine *machine)
@@ -684,20 +684,19 @@ int dso__data_get_fd(struct dso *dso, struct machine *machine)
if (dso->data.status == DSO_DATA_STATUS_ERROR)
return -1;

- if (pthread_mutex_lock(&dso__data_open_lock) < 0)
- return -1;
+ mutex_lock(&dso__data_open_lock);

try_to_open_dso(dso, machine);

if (dso->data.fd < 0)
- pthread_mutex_unlock(&dso__data_open_lock);
+ mutex_unlock(&dso__data_open_lock);

return dso->data.fd;
}

void dso__data_put_fd(struct dso *dso __maybe_unused)
{
- pthread_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)
@@ -756,7 +755,7 @@ dso_cache__free(struct dso *dso)
struct rb_root *root = &dso->data.cache;
struct rb_node *next = rb_first(root);

- pthread_mutex_lock(&dso->lock);
+ mutex_lock(&dso->lock);
while (next) {
struct dso_cache *cache;

@@ -765,7 +764,7 @@ dso_cache__free(struct dso *dso)
rb_erase(&cache->rb_node, root);
free(cache);
}
- pthread_mutex_unlock(&dso->lock);
+ mutex_unlock(&dso->lock);
}

static struct dso_cache *dso_cache__find(struct dso *dso, u64 offset)
@@ -802,7 +801,7 @@ dso_cache__insert(struct dso *dso, struct dso_cache *new)
struct dso_cache *cache;
u64 offset = new->offset;

- pthread_mutex_lock(&dso->lock);
+ mutex_lock(&dso->lock);
while (*p != NULL) {
u64 end;

@@ -823,7 +822,7 @@ dso_cache__insert(struct dso *dso, struct dso_cache *new)

cache = NULL;
out:
- pthread_mutex_unlock(&dso->lock);
+ mutex_unlock(&dso->lock);
return cache;
}

@@ -843,7 +842,7 @@ static ssize_t file_read(struct dso *dso, struct machine *machine,
{
ssize_t ret;

- pthread_mutex_lock(&dso__data_open_lock);
+ mutex_lock(&dso__data_open_lock);

/*
* dso->data.fd might be closed if other thread opened another
@@ -859,7 +858,7 @@ static ssize_t file_read(struct dso *dso, struct machine *machine,

ret = pread(dso->data.fd, data, DSO__DATA_CACHE_SIZE, offset);
out:
- pthread_mutex_unlock(&dso__data_open_lock);
+ mutex_unlock(&dso__data_open_lock);
return ret;
}

@@ -953,7 +952,7 @@ static int file_size(struct dso *dso, struct machine *machine)
struct stat st;
char sbuf[STRERR_BUFSIZE];

- pthread_mutex_lock(&dso__data_open_lock);
+ mutex_lock(&dso__data_open_lock);

/*
* dso->data.fd might be closed if other thread opened another
@@ -977,7 +976,7 @@ static int file_size(struct dso *dso, struct machine *machine)
dso->data.file_size = st.st_size;

out:
- pthread_mutex_unlock(&dso__data_open_lock);
+ mutex_unlock(&dso__data_open_lock);
return ret;
}

@@ -1192,7 +1191,7 @@ struct dso *dso__new(const char *name)
dso->root = NULL;
INIT_LIST_HEAD(&dso->node);
INIT_LIST_HEAD(&dso->data.open_entry);
- pthread_mutex_init(&dso->lock, NULL);
+ mutex_init(&dso->lock);
refcount_set(&dso->refcnt, 1);
}

@@ -1226,7 +1225,7 @@ void dso__delete(struct dso *dso)
dso__free_a2l(dso);
zfree(&dso->symsrc_filename);
nsinfo__zput(dso->nsinfo);
- pthread_mutex_destroy(&dso->lock);
+ mutex_destroy(&dso->lock);
free(dso);
}

diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index e4dddb76770d..e08b2ab48314 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -11,6 +11,7 @@
#include <stdio.h>
#include <linux/bitops.h>
#include "build-id.h"
+#include "mutex.h"

struct machine;
struct map;
@@ -132,7 +133,7 @@ struct dso_cache {
struct auxtrace_cache;

struct dso {
- pthread_mutex_t lock;
+ struct mutex lock;
struct list_head node;
struct rb_node rb_node; /* rbtree node sorted by long name */
struct rb_root *root; /* root of rbtree that rb_node is in */
diff --git a/tools/perf/util/mutex.c b/tools/perf/util/mutex.c
new file mode 100644
index 000000000000..b7264a1438c4
--- /dev/null
+++ b/tools/perf/util/mutex.c
@@ -0,0 +1,32 @@
+#include <mutex.h>
+#include <pthread.h>
+
+//to avoid the warning : implicit declaration of BUG_ON,
+//we add the following 2 headers.
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+
+void mutex_init(struct mutex *mtx)
+{
+pthread_mutexattr_t lock_attr;
+pthread_mutexattr_init(&lock_attr);
+pthread_mutexattr_settype(&lock_attr, PTHREAD_MUTEX_ERRORCHECK);
+BUG_ON(pthread_mutex_init(&mtx->lock, &lock_attr));
+//on success, returns 0.
+pthread_mutexattr_destroy(&lock_attr);
+}
+
+void mutex_destroy(struct mutex *mtx)
+{
+BUG_ON(pthread_mutex_destroy(&mtx->lock)); //on success, returns 0.
+}
+
+void mutex_lock(struct mutex *mtx)
+{
+BUG_ON(pthread_mutex_lock(&mtx->lock) != 0);
+}
+
+void mutex_unlock(struct mutex *mtx)
+{
+BUG_ON(pthread_mutex_unlock(&mtx->lock) != 0);
+}
diff --git a/tools/perf/util/mutex.h b/tools/perf/util/mutex.h
new file mode 100644
index 000000000000..ab2ebb98b24a
--- /dev/null
+++ b/tools/perf/util/mutex.h
@@ -0,0 +1,15 @@
+#ifndef __PERF_MUTEX_H
+#define _PERF_MUTEX_H
+
+#include <pthread.h>
+
+struct mutex {
+pthread_mutex_t lock;
+};
+
+void mutex_lock(struct mutex *mtx);
+void mutex_unlock(struct mutex *mtx);
+void mutex_init(struct mutex *mtx);
+void mutex_destroy(struct mutex *mtx);
+
+#endif /* _PERF_MUTEX_H */
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index a8f80e427674..342be12cfa1e 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1629,7 +1629,7 @@ int dso__load(struct dso *dso, struct map *map)
}

nsinfo__mountns_enter(dso->nsinfo, &nsc);
- pthread_mutex_lock(&dso->lock);
+ mutex_lock(&dso->lock);

/* check again under the dso->lock */
if (dso__loaded(dso)) {
@@ -1778,7 +1778,7 @@ int dso__load(struct dso *dso, struct map *map)
ret = 0;
out:
dso__set_loaded(dso);
- pthread_mutex_unlock(&dso->lock);
+ mutex_unlock(&dso->lock);
nsinfo__mountns_exit(&nsc);

return ret;
--
2.25.1