diff options
Diffstat (limited to 'libgo/go/runtime/time.go')
| -rw-r--r-- | libgo/go/runtime/time.go | 37 |
1 files changed, 31 insertions, 6 deletions
diff --git a/libgo/go/runtime/time.go b/libgo/go/runtime/time.go index 27d88d4..3cf13f1 100644 --- a/libgo/go/runtime/time.go +++ b/libgo/go/runtime/time.go @@ -215,11 +215,18 @@ func stopTimer(t *timer) bool { // resetTimer resets an inactive timer, adding it to the heap. //go:linkname resetTimer time.resetTimer -func resetTimer(t *timer, when int64) { +// Reports whether the timer was modified before it was run. +func resetTimer(t *timer, when int64) bool { if raceenabled { racerelease(unsafe.Pointer(t)) } - resettimer(t, when) + return resettimer(t, when) +} + +// modTimer modifies an existing timer. +//go:linkname modTimer time.modTimer +func modTimer(t *timer, when, period int64, f func(interface{}, uintptr), arg interface{}, seq uintptr) { + modtimer(t, when, period, f, arg, seq) } // Go runtime. @@ -395,14 +402,16 @@ func dodeltimer0(pp *p) { } // modtimer modifies an existing timer. -// This is called by the netpoll code. -func modtimer(t *timer, when, period int64, f func(interface{}, uintptr), arg interface{}, seq uintptr) { +// This is called by the netpoll code or time.Ticker.Reset. +// Reports whether the timer was modified before it was run. +func modtimer(t *timer, when, period int64, f func(interface{}, uintptr), arg interface{}, seq uintptr) bool { if when < 0 { when = maxWhen } status := uint32(timerNoStatus) wasRemoved := false + var pending bool var mp *m loop: for { @@ -412,6 +421,7 @@ loop: // This could lead to a self-deadlock. See #38070. mp = acquirem() if atomic.Cas(&t.status, status, timerModifying) { + pending = true // timer not yet run break loop } releasem(mp) @@ -424,6 +434,7 @@ loop: // Act like addtimer. if atomic.Cas(&t.status, status, timerModifying) { wasRemoved = true + pending = false // timer already run or stopped break loop } releasem(mp) @@ -433,6 +444,7 @@ loop: mp = acquirem() if atomic.Cas(&t.status, status, timerModifying) { atomic.Xadd(&t.pp.ptr().deletedTimers, -1) + pending = false // timer already stopped break loop } releasem(mp) @@ -503,14 +515,17 @@ loop: wakeNetPoller(when) } } + + return pending } // resettimer resets the time when a timer should fire. // If used for an inactive timer, the timer will become active. // This should be called instead of addtimer if the timer value has been, // or may have been, used previously. -func resettimer(t *timer, when int64) { - modtimer(t, when, t.period, t.f, t.arg, t.seq) +// Reports whether the timer was modified before it was run. +func resettimer(t *timer, when int64) bool { + return modtimer(t, when, t.period, t.f, t.arg, t.seq) } // cleantimers cleans up the head of the timer queue. This speeds up @@ -518,10 +533,20 @@ func resettimer(t *timer, when int64) { // slows down addtimer. Reports whether no timer problems were found. // The caller must have locked the timers for pp. func cleantimers(pp *p) { + gp := getg() for { if len(pp.timers) == 0 { return } + + // This loop can theoretically run for a while, and because + // it is holding timersLock it cannot be preempted. + // If someone is trying to preempt us, just return. + // We can clean the timers later. + if gp.preemptStop { + return + } + t := pp.timers[0] if t.pp.ptr() != pp { throw("cleantimers: bad p") |