From: Haomai Wang <haomaiwang@gmail.com>
Date: Thu, 30 Apr 2015 14:22:53 +0000 (+0800)
Subject: Event: Use atomic cas to avoid missing wakeup
X-Git-Tag: v9.0.1~29^2~1
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=5311eb0e5b9d64808335bb725286ef36a3836807;p=ceph.git

Event: Use atomic cas to avoid missing wakeup

Signed-off-by: Haomai Wang <haomaiwang@gmail.com>
---

diff --git a/src/msg/async/Event.cc b/src/msg/async/Event.cc
index 4bf2d3151a76..daa5fb1b1912 100644
--- a/src/msg/async/Event.cc
+++ b/src/msg/async/Event.cc
@@ -246,7 +246,7 @@ void EventCenter::delete_time_event(uint64_t id)
 
 void EventCenter::wakeup()
 {
-  if (!already_wakeup.read()) {
+  if (already_wakeup.cas(0, 1)) {
     ldout(cct, 1) << __func__ << dendl;
     char buf[1];
     buf[0] = 'c';
@@ -254,7 +254,6 @@ void EventCenter::wakeup()
     int n = write(notify_send_fd, buf, 1);
     // FIXME ?
     assert(n == 1);
-    already_wakeup.set(1);
   }
 }