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