[dm-devel] [PATCH 03/35] libmultipath: add optional wakeup functionality to lock.c

[mwilck at suse.com]

From: Martin Wilck <mwilck at suse.com>

Have struct mutex_lock take an optional wakeup function.
unlock() is renamed to __unlock() in order to prevent it from
being called by mistake.

Signed-off-by: Martin Wilck <mwilck at suse.com>
---
 libmultipath/libmultipath.version |  5 +++++
 libmultipath/lock.c               | 12 +++++++++++-
 libmultipath/lock.h               |  6 +++++-
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/libmultipath/libmultipath.version b/libmultipath/libmultipath.version
index c98cf7f..2107c51 100644
--- a/libmultipath/libmultipath.version
+++ b/libmultipath/libmultipath.version
@@ -292,3 +292,8 @@ LIBMULTIPATH_9.1.0 {
 global:
 	timespeccmp;
 } LIBMULTIPATH_9.0.0;
+
+LIBMULTIPATH_9.2.0 {
+global:
+	set_wakeup_fn;
+} LIBMULTIPATH_9.1.0;
diff --git a/libmultipath/lock.c b/libmultipath/lock.c
index 72c70e3..93b48db 100644
--- a/libmultipath/lock.c
+++ b/libmultipath/lock.c
@@ -3,6 +3,16 @@
 void cleanup_lock (void * data)
 {
 	struct mutex_lock *lock = data;
+	wakeup_fn *fn = lock->wakeup;
 
-	unlock(lock);
+	__unlock(lock);
+	if (fn)
+		fn();
+}
+
+void set_wakeup_fn(struct mutex_lock *lck, wakeup_fn *fn)
+{
+	lock(lck);
+	lck->wakeup = fn;
+	__unlock(lck);
 }
diff --git a/libmultipath/lock.h b/libmultipath/lock.h
index d99eedb..d7b779e 100644
--- a/libmultipath/lock.h
+++ b/libmultipath/lock.h
@@ -3,8 +3,11 @@
 
 #include <pthread.h>
 
+typedef void (wakeup_fn)(void);
+
 struct mutex_lock {
 	pthread_mutex_t mutex;
+	wakeup_fn *wakeup;
 };
 
 static inline void lock(struct mutex_lock *a)
@@ -22,7 +25,7 @@ static inline int timedlock(struct mutex_lock *a, struct timespec *tmo)
 	return pthread_mutex_timedlock(&a->mutex, tmo);
 }
 
-static inline void unlock(struct mutex_lock *a)
+static inline void __unlock(struct mutex_lock *a)
 {
 	pthread_mutex_unlock(&a->mutex);
 }
@@ -30,5 +33,6 @@ static inline void unlock(struct mutex_lock *a)
 #define lock_cleanup_pop(a) pthread_cleanup_pop(1)
 
 void cleanup_lock (void * data);
+void set_wakeup_fn(struct mutex_lock *lock, wakeup_fn *fn);
 
 #endif /* _LOCK_H */
-- 
2.33.0