1
0
mirror of https://github.com/golang/go synced 2024-11-19 15:05:00 -07:00
go/misc/cgo/test/issue1560.go
Russ Cox 0a006b4923 misc/cgo: prepare for 64-bit ints
In a few places, the existing cgo tests assume that a
Go int is the same as a C int. Making int 64 bits wide
on 64-bit platforms violates this assumption.
Change that code to assume that Go int32 and C int
are the same instead. That's still not great, but it's better,
and I am unaware of any systems we run on where it is not true.

Update #2188.

R=iant, r
CC=golang-dev
https://golang.org/cl/6552064
2012-09-24 14:58:45 -04:00

76 lines
1.6 KiB
Go

// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package cgotest
/*
#include <unistd.h>
unsigned int sleep(unsigned int seconds);
extern void BackgroundSleep(int);
void twoSleep(int);
*/
import "C"
import (
"runtime"
"testing"
"time"
)
var sleepDone = make(chan bool)
func parallelSleep(n int) {
C.twoSleep(C.int(n))
<-sleepDone
}
//export BackgroundSleep
func BackgroundSleep(n int32) {
go func() {
C.sleep(C.uint(n))
sleepDone <- true
}()
}
// wasteCPU starts a background goroutine to waste CPU
// to cause the power management to raise the CPU frequency.
// On ARM this has the side effect of making sleep more accurate.
func wasteCPU() chan struct{} {
done := make(chan struct{})
go func() {
for {
select {
case <-done:
return
default:
}
}
}()
// pause for a short amount of time to allow the
// power management to recognise load has risen.
<-time.After(300 * time.Millisecond)
return done
}
func testParallelSleep(t *testing.T) {
if runtime.GOARCH == "arm" {
// on ARM, the 1.3s deadline is frequently missed,
// and burning cpu seems to help
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(2))
defer close(wasteCPU())
}
sleepSec := 1
start := time.Now()
parallelSleep(sleepSec)
dt := time.Since(start)
t.Logf("sleep(%d) slept for %v", sleepSec, dt)
// bug used to run sleeps in serial, producing a 2*sleepSec-second delay.
if dt >= time.Duration(sleepSec)*1300*time.Millisecond {
t.Fatalf("parallel %d-second sleeps slept for %f seconds", sleepSec, dt.Seconds())
}
}