for i := 0; i < int(nevents); i++ {
		e := &evts[i]
		if e.typ == eventtypeClock {
			continue
		}

		hangup := e.fdReadwrite.flags&fdReadwriteHangup != 0
		var mode int32
		if e.typ == eventtypeFdRead || e.error != 0 || hangup {
			mode += 'r'
		}
		if e.typ == eventtypeFdWrite || e.error != 0 || hangup {
			mode += 'w'
		}
		if mode != 0 {
			pd := (*pollDesc)(unsafe.Pointer(uintptr(e.userdata)))

	return fd.readLock()
}

// ReadUnlock wraps FD.readUnlock.
func (fd *FD) ReadUnlock() {
	fd.readUnlock()
}

func isHangup(err error) bool {
	return err != nil && stringslite.HasSuffix(err.Error(), "Hangup")
}

func isInterrupted(err error) bool {
	return err != nil && stringslite.HasSuffix(err.Error(), "interrupted")
}

// IsPollDescriptor reports whether fd is the descriptor being used by the poller.

	{133, "EHWPOISON", "memory page has hardware error"},
}

// Signal table
var signalList = [...]struct {
	num  syscall.Signal
	name string
	desc string
}{
	{1, "SIGHUP", "hangup"},
	{2, "SIGINT", "interrupt"},
	{3, "SIGQUIT", "quit"},
	{4, "SIGILL", "illegal instruction"},
	{5, "SIGTRAP", "trace/breakpoint trap"},
	{6, "SIGABRT", "aborted"},
	{7, "SIGBUS", "bus error"},

	{133, "EHWPOISON", "memory page has hardware error"},
}

// Signal table
var signalList = [...]struct {
	num  syscall.Signal
	name string
	desc string
}{
	{1, "SIGHUP", "hangup"},
	{2, "SIGINT", "interrupt"},
	{3, "SIGQUIT", "quit"},
	{4, "SIGILL", "illegal instruction"},
	{5, "SIGTRAP", "trace/breakpoint trap"},
	{6, "SIGABRT", "aborted"},
	{7, "SIGBUS", "bus error"},

	{133, "EHWPOISON", "memory page has hardware error"},
}

// Signal table
var signalList = [...]struct {
	num  syscall.Signal
	name string
	desc string
}{
	{1, "SIGHUP", "hangup"},
	{2, "SIGINT", "interrupt"},
	{3, "SIGQUIT", "quit"},
	{4, "SIGILL", "illegal instruction"},
	{5, "SIGTRAP", "trace/breakpoint trap"},
	{6, "SIGABRT", "aborted"},
	{7, "SIGBUS", "bus error"},

	{1161, "EDC8161I", "The file system cannot currently be moved."},
}

// Signal table
var signalList = [...]struct {
	num  Signal
	name string
	desc string
}{
	{1, "SIGHUP", "hangup"},
	{2, "SIGINT", "interrupt"},
	{3, "SIGABT", "aborted"},
	{4, "SIGILL", "illegal instruction"},
	{5, "SIGPOLL", "pollable event"},
	{6, "SIGURG", "urgent I/O condition"},
	{7, "SIGSTOP", "stop process"},

	148: "no route to host",
	149: "operation already in progress",
	150: "operation now in progress",
	151: "stale NFS file handle",
}

// Signal table
var signals = [...]string{
	1:  "hangup",
	2:  "interrupt",
	3:  "quit",
	4:  "illegal Instruction",
	5:  "trace/Breakpoint Trap",
	6:  "abort",
	7:  "emulation Trap",
	8:  "arithmetic Exception",
	9:  "killed",
	10: "bus Error",

	const backendResponse = "I am the backend"
	const backendStatus = 404
	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == "GET" && r.FormValue("mode") == "hangup" {
			c, _, _ := w.(http.Hijacker).Hijack()
			c.Close()
			return
		}
		if len(r.TransferEncoding) > 0 {
			t.Errorf("backend got unexpected TransferEncoding: %v", r.TransferEncoding)
		}

	SIGBUS  = Signal(0x7)
	SIGFPE  = Signal(0x8)
	SIGKILL = Signal(0x9)
	SIGSEGV = Signal(0xb)
	SIGPIPE = Signal(0xd)
	SIGALRM = Signal(0xe)
	SIGTERM = Signal(0xf)
)

var signals = [...]string{
	1:  "hangup",
	2:  "interrupt",
	3:  "quit",
	4:  "illegal instruction",
	5:  "trace/breakpoint trap",
	6:  "aborted",
	7:  "bus error",
	8:  "floating point exception",
	9:  "killed",
	10: "user defined signal 1",

		gs:          make(map[GoID]*GoroutineSummary),
		tasks:       make(map[TaskID]*UserTaskSummary),
		syscallingP: make(map[ProcID]GoID),
		syscallingG: make(map[GoID]ProcID),
		rangesP:     make(map[rangeP]GoID),
	}
}

type rangeP struct {
	id   ProcID
	name string
}

// Event feeds a single event into the stats summarizer.
func (s *Summarizer) Event(ev *Event) {
	if s.syncTs == 0 {
		s.syncTs = ev.Time()