From 1e66428d59919b4e2f58e47d989ef10d1781b3aa Mon Sep 17 00:00:00 2001
From: Christopher Wedgwood <cw@f00f.org>
Date: Thu, 4 Feb 2010 13:09:02 -0800
Subject: [PATCH] time: Sleep through interruptions

R=rsc
CC=golang-dev
https://golang.org/cl/202043
---
 src/pkg/time/sleep.go      | 15 +++++++++++++--
 src/pkg/time/sleep_test.go | 26 ++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 2 deletions(-)
 create mode 100644 src/pkg/time/sleep_test.go

diff --git a/src/pkg/time/sleep.go b/src/pkg/time/sleep.go
index fe0ddce4a9b..5de5374cea7 100644
--- a/src/pkg/time/sleep.go
+++ b/src/pkg/time/sleep.go
@@ -11,5 +11,16 @@ import (
 
 // Sleep pauses the current goroutine for at least ns nanoseconds. Higher resolution
 // sleeping may be provided by syscall.Nanosleep on some operating systems.
-// Sleep returns os.EINTR if interrupted.
-func Sleep(ns int64) os.Error { return os.NewSyscallError("sleep", syscall.Sleep(ns)) }
+func Sleep(ns int64) os.Error {
+	// TODO(cw): use monotonic-time once it's available
+	t := Nanoseconds()
+	end := t + ns
+	for t < end {
+		errno := syscall.Sleep(end - t)
+		if errno != 0 && errno != syscall.EINTR {
+			return os.NewSyscallError("sleep", errno)
+		}
+		t = Nanoseconds()
+	}
+	return nil
+}
diff --git a/src/pkg/time/sleep_test.go b/src/pkg/time/sleep_test.go
new file mode 100644
index 00000000000..7ec6c49439c
--- /dev/null
+++ b/src/pkg/time/sleep_test.go
@@ -0,0 +1,26 @@
+// Copyright 2009 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 time_test
+
+import (
+	"os"
+	"syscall"
+	"testing"
+	. "time"
+)
+
+func TestSleep(t *testing.T) {
+	const delay = int64(100e6)
+	go func() {
+		Sleep(delay / 2)
+		syscall.Kill(os.Getpid(), syscall.SIGCHLD)
+	}()
+	start := Nanoseconds()
+	Sleep(delay)
+	duration := Nanoseconds() - start
+	if duration < delay {
+		t.Fatalf("Sleep(%d) slept for only %d ns", delay, duration)
+	}
+}