Skip to content

Commit

Permalink
glog: don't hold mutex when sync'ing (#68)
Browse files Browse the repository at this point in the history
Some environments are slow when syncing and holding the lock might cause contention.

cl/621846576 (google-internal)
  • Loading branch information
chressie authored Apr 4, 2024
1 parent b256bbe commit 861d094
Showing 1 changed file with 16 additions and 9 deletions.
25 changes: 16 additions & 9 deletions glog_file.go
Original file line number Diff line number Diff line change
Expand Up @@ -369,23 +369,30 @@ func (s *fileSink) Flush() error {

// 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 {
firstErr = err
}
}

// 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
Expand Down

0 comments on commit 861d094

Please sign in to comment.