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 // +build linux,freebsd,openbsd
   7
   8 package cgotest
   9
  10 /*
  11 #include <unistd.h>
  12 #include <sys/syscall.h>
  13 void Gosched(void);
  14 static int Ctid(void) { Gosched(); return syscall(SYS_gettid); }
  15 */
  16 import "C"
  17
  18 import (
  19         "runtime"
  20         "syscall"
  21         "testing"
  22         "time"
  23 )
  24
  25 //export Gosched
  26 func Gosched() {
  27         runtime.Gosched()
  28 }
  29
  30 func init() {
  31         testThreadLockFunc = testThreadLock
  32 }
  33
  34 func testThreadLock(t *testing.T) {
  35         stop := make(chan int)
  36         go func() {
  37                 // We need the G continue running,
  38                 // so the M has a chance to run this G.
  39                 for {
  40                         select {
  41                         case <-stop:
  42                                 return
  43                         case <-time.After(time.Millisecond * 100):
  44                         }
  45                 }
  46         }()
  47         defer close(stop)
  48
  49         for i := 0; i < 1000; i++ {
  50                 if C.int(syscall.Gettid()) != C.Ctid() {
  51                         t.Fatalf("cgo has not locked OS thread")
  52                 }
  53         }
  54 }