|
|
@@ -0,0 +1,66 @@
|
|
|
+// Copyright 2014 Google Inc. All rights reserved.
|
|
|
+// Use of this source code is governed by a BSD-style
|
|
|
+// license that can be found in the LICENSE file.
|
|
|
+
|
|
|
+package uuid
|
|
|
+
|
|
|
+import (
|
|
|
+ "flag"
|
|
|
+ "runtime"
|
|
|
+ "testing"
|
|
|
+ "time"
|
|
|
+)
|
|
|
+
|
|
|
+// This test is only run when --regressions is passed on the go test line.
|
|
|
+var regressions = flag.Bool("regressions", false, "run uuid regression tests")
|
|
|
+
|
|
|
+// TestClockSeqRace tests for a particular race condition of returning two
|
|
|
+// identical Version1 UUIDs. The duration of 1 minute was chosen as the race
|
|
|
+// condition, before being fixed, nearly always occured in under 30 seconds.
|
|
|
+func TestClockSeqRace(t *testing.T) {
|
|
|
+ if !*regressions {
|
|
|
+ t.Skip("skipping regression tests")
|
|
|
+ }
|
|
|
+ duration := time.Minute
|
|
|
+
|
|
|
+ done := make(chan struct{})
|
|
|
+ defer close(done)
|
|
|
+
|
|
|
+ ch := make(chan UUID, 10000)
|
|
|
+ ncpu := runtime.NumCPU()
|
|
|
+ switch ncpu {
|
|
|
+ case 0, 1:
|
|
|
+ // We can't run the test effectively.
|
|
|
+ t.Skip("skipping race test, only one CPU detected")
|
|
|
+ return
|
|
|
+ default:
|
|
|
+ runtime.GOMAXPROCS(ncpu)
|
|
|
+ }
|
|
|
+ for i := 0; i < ncpu; i++ {
|
|
|
+ go func() {
|
|
|
+ for {
|
|
|
+ select {
|
|
|
+ case <-done:
|
|
|
+ return
|
|
|
+ case ch <- NewUUID():
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }()
|
|
|
+ }
|
|
|
+
|
|
|
+ uuids := make(map[string]bool)
|
|
|
+ cnt := 0
|
|
|
+ start := time.Now()
|
|
|
+ for u := range ch {
|
|
|
+ s := u.String()
|
|
|
+ if uuids[s] {
|
|
|
+ t.Errorf("duplicate uuid after %d in %v: %s", cnt, time.Since(start), s)
|
|
|
+ return
|
|
|
+ }
|
|
|
+ uuids[s] = true
|
|
|
+ if time.Since(start) > duration {
|
|
|
+ return
|
|
|
+ }
|
|
|
+ cnt++
|
|
|
+ }
|
|
|
+}
|