Golang util.Trace类代码示例

// waitUntilFreshAndBlock waits until cache is at least as fresh as given <resourceVersion>.
// NOTE: This function acquired lock and doesn't release it.
// You HAVE TO explicitly call w.RUnlock() after this function.
func (w *watchCache) waitUntilFreshAndBlock(resourceVersion uint64, trace *util.Trace) error {
	startTime := w.clock.Now()
	go func() {
		// Wake us up when the time limit has expired.  The docs
		// promise that time.After (well, NewTimer, which it calls)
		// will wait *at least* the duration given. Since this go
		// routine starts sometime after we record the start time, and
		// it will wake up the loop below sometime after the broadcast,
		// we don't need to worry about waking it up before the time
		// has expired accidentally.
		<-w.clock.After(MaximumListWait)
		w.cond.Broadcast()
	}()

	w.RLock()
	if trace != nil {
		trace.Step("watchCache locked acquired")
	}
	for w.resourceVersion < resourceVersion {
		if w.clock.Since(startTime) >= MaximumListWait {
			return fmt.Errorf("time limit exceeded while waiting for resource version %v (current value: %v)", resourceVersion, w.resourceVersion)
		}
		w.cond.Wait()
	}
	if trace != nil {
		trace.Step("watchCache fresh enough")
	}
	return nil
}

// Schedule tries to schedule the given pod to one of node in the node list.
// If it succeeds, it will return the name of the node.
// If it fails, it will return a Fiterror error with reasons.
func (g *genericScheduler) Schedule(pod *api.Pod, nodeLister algorithm.NodeLister) (string, error) {
	var trace *util.Trace
	if pod != nil {
		trace = util.NewTrace(fmt.Sprintf("Scheduling %s/%s", pod.Namespace, pod.Name))
	} else {
		trace = util.NewTrace("Scheduling <nil> pod")
	}
	defer trace.LogIfLong(20 * time.Millisecond)

	nodes, err := nodeLister.List()
	if err != nil {
		return "", err
	}
	if len(nodes) == 0 {
		return "", ErrNoNodesAvailable
	}

	// Used for all fit and priority funcs.
	err = g.cache.UpdateNodeNameToInfoMap(g.cachedNodeInfoMap)
	if err != nil {
		return "", err
	}

	trace.Step("Computing predicates")
	filteredNodes, failedPredicateMap, err := findNodesThatFit(pod, g.cachedNodeInfoMap, nodes, g.predicates, g.extenders)
	if err != nil {
		return "", err
	}

	if len(filteredNodes) == 0 {
		return "", &FitError{
			Pod:              pod,
			FailedPredicates: failedPredicateMap,
		}
	}

	trace.Step("Prioritizing")
	meta := g.priorityMetaProducer(pod)
	priorityList, err := PrioritizeNodes(pod, g.cachedNodeInfoMap, meta, g.prioritizers, filteredNodes, g.extenders)
	if err != nil {
		return "", err
	}

	trace.Step("Selecting host")
	return g.selectHost(priorityList)
}