Merge pull request #50 from ncdc/fix-write-close-deadlock

Fix write/close deadlock
moby · Apr 9, 2015 · 99515db · 99515db
2 parents e731c8f + d91d6d1
commit 99515db
Showing 1 changed file with 15 additions and 0 deletions.
diff --git a/connection.go b/connection.go
@@ -89,10 +89,25 @@ Loop:
 			if timer != nil {
 				timer.Stop()
 			}
+
+			// Start a goroutine to drain resetChan. This is needed because we've seen
+			// some unit tests with large numbers of goroutines get into a situation
+			// where resetChan fills up, at least 1 call to Write() is still trying to
+			// send to resetChan, the connection gets closed, and this case statement
+			// attempts to grab the write lock that Write() already has, causing a
+			// deadlock.
+			//
+			// See https://github.com/docker/spdystream/issues/49 for more details.
+			go func() {
+				for _ = range resetChan {
+				}
+			}()
+
 			i.writeLock.Lock()
 			close(resetChan)
 			i.resetChan = nil
 			i.writeLock.Unlock()
+
 			break Loop
 		}
 	}