mgclimit.go | Explore in Territory

var gcCPULimiter …

type gcCPULimiterState …

// limiting returns true if the CPU limiter is currently enabled, meaning the Go GC
// should take action to limit CPU utilization.
//
// It is safe to call concurrently with other operations.
func (l *gcCPULimiterState) limiting() bool { … }

// startGCTransition notifies the limiter of a GC transition.
//
// This call takes ownership of the limiter and disables all other means of
// updating the limiter. Release ownership by calling finishGCTransition.
//
// It is safe to call concurrently with other operations.
func (l *gcCPULimiterState) startGCTransition(enableGC bool, now int64) { … }

// finishGCTransition notifies the limiter that the GC transition is complete
// and releases ownership of it. It also accumulates STW time in the bucket.
// now must be the timestamp from the end of the STW pause.
func (l *gcCPULimiterState) finishGCTransition(now int64) { … }

const gcCPULimiterUpdatePeriod …

// needUpdate returns true if the limiter's maximum update period has been
// exceeded, and so would benefit from an update.
func (l *gcCPULimiterState) needUpdate(now int64) bool { … }

// addAssistTime notifies the limiter of additional assist time. It will be
// included in the next update.
func (l *gcCPULimiterState) addAssistTime(t int64) { … }

// addIdleTime notifies the limiter of additional time a P spent on the idle list. It will be
// subtracted from the total CPU time in the next update.
func (l *gcCPULimiterState) addIdleTime(t int64) { … }

// update updates the bucket given runtime-specific information. now is the
// current monotonic time in nanoseconds.
//
// This is safe to call concurrently with other operations, except *GCTransition.
func (l *gcCPULimiterState) update(now int64) { … }

// updateLocked is the implementation of update. l.lock must be held.
func (l *gcCPULimiterState) updateLocked(now int64) { … }

// accumulate adds time to the bucket and signals whether the limiter is enabled.
//
// This is an internal function that deals just with the bucket. Prefer update.
// l.lock must be held.
func (l *gcCPULimiterState) accumulate(mutatorTime, gcTime int64) { … }

// tryLock attempts to lock l. Returns true on success.
func (l *gcCPULimiterState) tryLock() bool { … }

// unlock releases the lock on l. Must be called if tryLock returns true.
func (l *gcCPULimiterState) unlock() { … }

const capacityPerProc …

// resetCapacity updates the capacity based on GOMAXPROCS. Must not be called
// while the GC is enabled.
//
// It is safe to call concurrently with other operations.
func (l *gcCPULimiterState) resetCapacity(now int64, nprocs int32) { … }

type limiterEventType …

const limiterEventNone …

const limiterEventIdleMarkWork …

const limiterEventMarkAssist …

const limiterEventScavengeAssist …

const limiterEventIdle …

const limiterEventBits …

const limiterEventTypeMask …

const limiterEventStampNone …

type limiterEventStamp …

// makeLimiterEventStamp creates a new stamp from the event type and the current timestamp.
func makeLimiterEventStamp(typ limiterEventType, now int64) limiterEventStamp { … }

// duration computes the difference between now and the start time stored in the stamp.
//
// Returns 0 if the difference is negative, which may happen if now is stale or if the
// before and after timestamps cross a 2^(64-limiterEventBits) boundary.
func (s limiterEventStamp) duration(now int64) int64 { … }

// type extracts the event type from the stamp.
func (s limiterEventStamp) typ() limiterEventType { … }

type limiterEvent …

// start begins tracking a new limiter event of the current type. If an event
// is already in flight, then a new event cannot begin because the current time is
// already being attributed to that event. In this case, this function returns false.
// Otherwise, it returns true.
//
// The caller must be non-preemptible until at least stop is called or this function
// returns false. Because this is trying to measure "on-CPU" time of some event, getting
// scheduled away during it can mean that whatever we're measuring isn't a reflection
// of "on-CPU" time. The OS could deschedule us at any time, but we want to maintain as
// close of an approximation as we can.
func (e *limiterEvent) start(typ limiterEventType, now int64) bool { … }

// consume acquires the partial event CPU time from any in-flight event.
// It achieves this by storing the current time as the new event time.
//
// Returns the type of the in-flight event, as well as how long it's currently been
// executing for. Returns limiterEventNone if no event is active.
func (e *limiterEvent) consume(now int64) (typ limiterEventType, duration int64) { … }

// stop stops the active limiter event. Throws if the
//
// The caller must be non-preemptible across the event. See start as to why.
func (e *limiterEvent) stop(typ limiterEventType, now int64) { … }
go/src/runtime/mgclimit.go
