[sheepdog] [PATCH v2 1/3] sheep: make {register, unregister}_event thread safe

[Liu Yuan]

This allow us to call even handling functions in worker thread

Signed-off-by: Liu Yuan <namei.unix at gmail.com>
---
 lib/event.c          |   14 ++++++++++++--
 shepherd/Makefile.am |    2 +-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/lib/event.c b/lib/event.c
index 88078f4..16aa921 100644
--- a/lib/event.c
+++ b/lib/event.c
@@ -21,6 +21,7 @@
 
 static int efd;
 static struct rb_root events_tree = RB_ROOT;
+static struct sd_lock events_lock = SD_LOCK_INITIALIZER;
 
 static void timer_handler(int fd, int events, void *data)
 {
@@ -92,8 +93,12 @@ int init_event(int nr)
 static struct event_info *lookup_event(int fd)
 {
 	struct event_info key = { .fd = fd };
+	struct event_info *ret;
 
-	return rb_search(&events_tree, &key, rb, event_cmp);
+	sd_read_lock(&events_lock);
+	ret = rb_search(&events_tree, &key, rb, event_cmp);
+	sd_unlock(&events_lock);
+	return ret;
 }
 
 int register_event_prio(int fd, event_handler_t h, void *data, int prio)
@@ -116,8 +121,11 @@ int register_event_prio(int fd, event_handler_t h, void *data, int prio)
 	if (ret) {
 		sd_err("failed to add epoll event: %m");
 		free(ei);
-	} else
+	} else {
+		sd_write_lock(&events_lock);
 		rb_insert(&events_tree, ei, rb, event_cmp);
+		sd_unlock(&events_lock);
+	}
 
 	return ret;
 }
@@ -135,7 +143,9 @@ void unregister_event(int fd)
 	if (ret)
 		sd_err("failed to delete epoll event for fd %d: %m", fd);
 
+	sd_write_lock(&events_lock);
 	rb_erase(&ei->rb, &events_tree);
+	sd_unlock(&events_lock);
 	free(ei);
 
 	/*
diff --git a/shepherd/Makefile.am b/shepherd/Makefile.am
index 33a3da6..86f45be 100644
--- a/shepherd/Makefile.am
+++ b/shepherd/Makefile.am
@@ -25,7 +25,7 @@ sbin_PROGRAMS		= shepherd
 
 shepherd_SOURCES		= shepherd.c
 
-shepherd_LDADD	  	= ../lib/libsheepdog.a
+shepherd_LDADD	  	= ../lib/libsheepdog.a -lpthread
 shepherd_DEPENDENCIES	= ../lib/libsheepdog.a
 
 EXTRA_DIST		=
-- 
1.7.9.5