func UserTasksHandlerFunc(t *parsedTrace) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		tasks := t.summary.Tasks

		// Summarize groups of tasks with the same name.
		summary := make(map[string]taskStats)
		for _, task := range tasks {
			stats, ok := summary[task.Name]
			if !ok {
				stats.Type = task.Name
			}
			stats.add(task)

//
// The precise representation is an implementation detail, but for the
// sake of documentation, 0s are free pages and 1s are allocated pages.
type pallocBits pageBits

// summarize returns a packed summary of the bitmap in pallocBits.
func (b *pallocBits) summarize() pallocSum {
	var start, most, cur uint
	const notSetYet = ^uint(0) // sentinel for start value
	start = notSetYet
	for i := 0; i < len(b); i++ {
		x := b[i]

                val currentFingerprint = host.fingerprintOf(fileSystemInputs)
                if (currentFingerprint != fileSystemInputsFingerprint) {
                    // TODO: summarize what has changed (see https://github.com/gradle/configuration-cache/issues/282)
                    return "an input to $workDisplayName has changed"
                }
            }

)

// UserRegionsHandlerFunc returns a HandlerFunc that reports all regions found in the trace.
func UserRegionsHandlerFunc(t *parsedTrace) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// Summarize all the regions.
		summary := make(map[regionFingerprint]regionStats)
		for _, g := range t.summary.Goroutines {
			for _, r := range g.Regions {
				id := fingerprintRegion(r)
				stats, ok := summary[id]
				if !ok {

func (b *PallocBits) Free(i, n uint)             { (*pallocBits)(b).free(i, n) }
func (b *PallocBits) Summarize() PallocSum       { return PallocSum((*pallocBits)(b).summarize()) }
func (b *PallocBits) PopcntRange(i, n uint) uint { return (*pageBits)(b).popcntRange(i, n) }

// SummarizeSlow is a slow but more obviously correct implementation
// of (*pallocBits).summarize. Used for testing.
func SummarizeSlow(b *PallocBits) PallocSum {
	var start, most, end uint

  // CHECK: [[tensor:%.*]] = tf_mlrt.await
  // CHECK: tf_mlrt.executeop([[tensor]])
  %0 = "tf.StringFormat"(%arg0) {__op_key = 0: i32, device = "/job:localhost/replica:0/task:0/device:CPU:0", placeholder = "{}", strtemplate = "%s", summarize = 3 : i64, template = "Outside compiled {}"} : (tensor<i32>) -> tensor<!tf_type.string>

    private
    val problemsService: InternalProblems,

    private
    val failureFactory: FailureFactory

) : AbstractProblemsListener(), ProblemReporter, AutoCloseable {

    private
    val summarizer = ConfigurationCacheProblemsSummary()

    private
    val buildNameHandler = BuildNameHandler()

    private
    val postBuildHandler = PostBuildProblemsHandler()

    private

	lastSyscallTime      Time
	lastSyscallBlockTime Time
	lastRangeTime        map[string]Time
	activeRegions        []*UserRegionSummary // stack of active regions
}

// Summarizer constructs per-goroutine time statistics for v2 traces.
type Summarizer struct {
	// gs contains the map of goroutine summaries we're building up to return to the caller.
	gs map[GoID]*GoroutineSummary

	// See tests for examples.
	cppRegExp                = regexp.MustCompile(`^(?:[_a-zA-Z]\w*::)+(_*[A-Z]\w*::~?[_a-zA-Z]\w*(?:<.*>)?)`)
	cppAnonymousPrefixRegExp = regexp.MustCompile(`^\(anonymous namespace\)::`)
)

// Graph summarizes a performance profile into a format that is
// suitable for visualization.
type Graph struct {
	Nodes Nodes
}

// Options encodes the options for constructing a graph
type Options struct {

	fdseq atomic.Uintptr // protects against stale pollDesc

	// atomicInfo holds bits from closing, rd, and wd,
	// which are only ever written while holding the lock,
	// summarized for use by netpollcheckerr,
	// which cannot acquire the lock.
	// After writing these fields under lock in a way that
	// might change the summary, code must call publishInfo
	// before releasing the lock.