glog: don't hold mutex when sync'ing (#68)
Some environments are slow when syncing and holding the lock might cause contention.
cl/621846576 (google-internal)
diff --git a/glog_file.go b/glog_file.go
index e7d125c..a1551db 100644
--- a/glog_file.go
+++ b/glog_file.go
@@ -369,9 +369,6 @@
// flush flushes all logs of severity threshold or greater.
func (s *fileSink) flush(threshold logsink.Severity) error {
- s.mu.Lock()
- defer s.mu.Unlock()
-
var firstErr error
updateErr := func(err error) {
if err != nil && firstErr == nil {
@@ -379,13 +376,23 @@
}
}
- // Flush from fatal down, in case there's trouble flushing.
- for sev := logsink.Fatal; sev >= threshold; sev-- {
- file := s.file[sev]
- if file != nil {
- updateErr(file.Flush())
- updateErr(file.Sync())
+ // Remember where we flushed, so we can call sync without holding
+ // the lock.
+ var files []flushSyncWriter
+ func() {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+ // Flush from fatal down, in case there's trouble flushing.
+ for sev := logsink.Fatal; sev >= threshold; sev-- {
+ if file := s.file[sev]; file != nil {
+ updateErr(file.Flush())
+ files = append(files, file)
+ }
}
+ }()
+
+ for _, file := range files {
+ updateErr(file.Sync())
}
return firstErr
