blob: edd523bc80c0a25cb1d796414106584fdcabc4a6 [file] [log] [blame]
// 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 time
func init() {
// force US/Pacific for time zone tests
var Interrupt = interrupt
var DaysIn = daysIn
func empty(arg interface{}, seq uintptr) {}
// Test that a runtimeTimer with a duration so large it overflows
// does not cause other timers to hang.
// This test has to be in internal_test.go since it fiddles with
// unexported data structures.
func CheckRuntimeTimerOverflow() {
// We manually create a runtimeTimer to bypass the overflow
// detection logic in NewTimer: we're testing the underlying
// runtime.addtimer function.
r := &runtimeTimer{
when: runtimeNano() + (1<<63 - 1),
f: empty,
arg: nil,
// Start a goroutine that should send on t.C right away.
t := NewTimer(1)
defer func() {
// Subsequent tests won't work correctly if we don't stop the
// overflow timer and kick the timer proc back into service.
// The timer proc is now sleeping and can only be awoken by
// adding a timer to the *beginning* of the heap. We can't
// wake it up by calling NewTimer since other tests may have
// left timers running that should have expired before ours.
// Instead we zero the overflow timer duration and start it
// once more.
r.when = 0
// If the test fails, we will hang here until the timeout in the testing package
// fires, which is 10 minutes. It would be nice to catch the problem sooner,
// but there is no reliable way to guarantee that timerproc schedules without
// doing something involving timerproc itself. Previous failed attempts have
// tried calling runtime.Gosched and runtime.GC, but neither is reliable.
// So we fall back to hope: We hope we don't hang here.