code review 6202043: runtime: fix build for Linux/ARM

misc/cgo/test/issue1560.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 int) {
         go func() {
                 C.sleep(C.uint(n))
                 sleepDone <- true
         }()
 }
 
 func testParallelSleep(t *testing.T) {
+        sleepSec := 1
+        if runtime.GOARCH == "arm" {
+                // on ARM, the 1.3s deadline is frequently missed,
+                // so increase sleep time to 2s
+                sleepSec = 2
+        }
         start := time.Now()
-        parallelSleep(1)
+        parallelSleep(sleepSec)
         dt := time.Now().Sub(start)
-        // bug used to run sleeps in serial, producing a 2-second delay.
-        if dt >= 1300*time.Millisecond {
-                t.Fatalf("parallel 1-second sleeps slept for %f seconds", dt.Seconds())
+        // 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())
         }
 }