diff options
Diffstat (limited to 'src/time/internal_test.go')
| -rw-r--r-- | src/time/internal_test.go | 52 |
1 files changed, 17 insertions, 35 deletions
diff --git a/src/time/internal_test.go b/src/time/internal_test.go index 35ce69b228..ffe54e47c2 100644 --- a/src/time/internal_test.go +++ b/src/time/internal_test.go @@ -33,48 +33,30 @@ 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. +// Test that a runtimeTimer with a period that would overflow when on +// expiration does not throw or 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. +func CheckRuntimeTimerPeriodOverflow() { + // We manually create a runtimeTimer with huge period, but that expires + // immediately. The public Timer interface would require waiting for + // the entire period before the first update. r := &runtimeTimer{ - when: runtimeNano() + (1<<63 - 1), - f: empty, - arg: nil, + when: runtimeNano(), + period: 1<<63 - 1, + f: empty, + arg: nil, } startTimer(r) + defer stopTimer(r) - // 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. - stopTimer(r) - t.Stop() - resetTimer(r, 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 timers are run without doing something involving the scheduler. - // 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. - <-t.C + // If this test fails, we will either throw (when siftdownTimer detects + // bad when on update), or other timers will hang (if the timer in a + // heap is in a bad state). There is no reliable way to test this, but + // we wait on a short timer here as a smoke test (alternatively, timers + // in later tests may hang). + <-After(25 * Millisecond) } var ( |