misc/cgo/test/cgo_thread_lock.go

   1 // Copyright 2016 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 //go:build linux && freebsd && openbsd
   6
   7 package cgotest
   8
   9 /*
  10 #include <unistd.h>
  11 #include <sys/syscall.h>
  12 void Gosched(void);
  13 static int Ctid(void) { Gosched(); return syscall(SYS_gettid); }
  14 */
  15 import "C"
  16
  17 import (
  18         "runtime"
  19         "syscall"
  20         "testing"
  21         "time"
  22 )
  23
  24 //export Gosched
  25 func Gosched() {
  26         runtime.Gosched()
  27 }
  28
  29 func init() {
  30         testThreadLockFunc = testThreadLock
  31 }
  32
  33 func testThreadLock(t *testing.T) {
  34         stop := make(chan int)
  35         go func() {
  36                 // We need the G continue running,
  37                 // so the M has a chance to run this G.
  38                 for {
  39                         select {
  40                         case <-stop:
  41                                 return
  42                         case <-time.After(time.Millisecond * 100):
  43                         }
  44                 }
  45         }()
  46         defer close(stop)
  47
  48         for i := 0; i < 1000; i++ {
  49                 if C.int(syscall.Gettid()) != C.Ctid() {
  50                         t.Fatalf("cgo has not locked OS thread")
  51                 }
  52         }
  53 }