libgo/go/runtime/chanbarrier_test.go

   1 // Copyright 2015 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package runtime_test
   6
   7 import (
   8         "runtime"
   9         "sync"
  10         "testing"
  11 )
  12
  13 type response struct {
  14 }
  15
  16 type myError struct {
  17 }
  18
  19 func (myError) Error() string { return "" }
  20
  21 func doRequest(useSelect bool) (*response, error) {
  22         type async struct {
  23                 resp *response
  24                 err  error
  25         }
  26         ch := make(chan *async, 0)
  27         done := make(chan struct{}, 0)
  28
  29         if useSelect {
  30                 go func() {
  31                         select {
  32                         case ch <- &async{resp: nil, err: myError{}}:
  33                         case <-done:
  34                         }
  35                 }()
  36         } else {
  37                 go func() {
  38                         ch <- &async{resp: nil, err: myError{}}
  39                 }()
  40         }
  41
  42         r := <-ch
  43         runtime.Gosched()
  44         return r.resp, r.err
  45 }
  46
  47 func TestChanSendSelectBarrier(t *testing.T) {
  48         testChanSendBarrier(true)
  49 }
  50
  51 func TestChanSendBarrier(t *testing.T) {
  52         testChanSendBarrier(false)
  53 }
  54
  55 func testChanSendBarrier(useSelect bool) {
  56         var wg sync.WaitGroup
  57         var globalMu sync.Mutex
  58         outer := 100
  59         inner := 100000
  60         if testing.Short() {
  61                 outer = 10
  62                 inner = 1000
  63         }
  64         for i := 0; i < outer; i++ {
  65                 wg.Add(1)
  66                 go func() {
  67                         defer wg.Done()
  68                         var garbage []byte
  69                         for j := 0; j < inner; j++ {
  70                                 _, err := doRequest(useSelect)
  71                                 _, ok := err.(myError)
  72                                 if !ok {
  73                                         panic(1)
  74                                 }
  75                                 garbage = make([]byte, 1<<10)
  76                         }
  77                         globalMu.Lock()
  78                         global = garbage
  79                         globalMu.Unlock()
  80                 }()
  81         }
  82         wg.Wait()
  83 }