Golang trace.Parse函數代碼示例

func TestTrace(t *testing.T) {
	skipTraceTestsIfNeeded(t)
	buf := new(bytes.Buffer)
	if err := StartTrace(buf); err != nil {
		t.Fatalf("failed to start tracing: %v", err)
	}
	StopTrace()
	_, err := trace.Parse(buf)
	if err != nil {
		t.Fatalf("failed to parse trace: %v", err)
	}
}

func parseTrace(r io.Reader) ([]*trace.Event, map[uint64]*trace.GDesc, error) {
	events, err := trace.Parse(r)
	if err != nil {
		return nil, nil, err
	}
	gs := trace.GoroutineStats(events)
	for goid := range gs {
		// We don't do any particular checks on the result at the moment.
		// But still check that RelatedGoroutines does not crash, hang, etc.
		_ = trace.RelatedGoroutines(events, goid)
	}
	return events, gs, nil
}

// TestGoroutineCount tests runnable/running goroutine counts computed by generateTrace
// remain in the valid range.
//   - the counts must not be negative. generateTrace will return an error.
//   - the counts must not include goroutines blocked waiting on channels or in syscall.
func TestGoroutineCount(t *testing.T) {
	w := trace.NewWriter()
	w.Emit(trace.EvBatch, 0, 0)  // start of per-P batch event [pid, timestamp]
	w.Emit(trace.EvFrequency, 1) // [ticks per second]

	// In this test, we assume a valid trace contains EvGoWaiting or EvGoInSyscall
	// event for every blocked goroutine.

	// goroutine 10: blocked
	w.Emit(trace.EvGoCreate, 1, 10, 1, 1) // [timestamp, new goroutine id, new stack id, stack id]
	w.Emit(trace.EvGoWaiting, 1, 10)      // [timestamp, goroutine id]

	// goroutine 20: in syscall
	w.Emit(trace.EvGoCreate, 1, 20, 2, 1)
	w.Emit(trace.EvGoInSyscall, 1, 20) // [timestamp, goroutine id]

	// goroutine 30: runnable
	w.Emit(trace.EvGoCreate, 1, 30, 5, 1)

	w.Emit(trace.EvProcStart, 2, 0) // [timestamp, thread id]

	// goroutine 40: runnable->running->runnable
	w.Emit(trace.EvGoCreate, 1, 40, 7, 1)
	w.Emit(trace.EvGoStartLocal, 1, 40) // [timestamp, goroutine id]
	w.Emit(trace.EvGoSched, 1, 8)       // [timestamp, stack]

	events, err := trace.Parse(w, "")
	if err != nil {
		t.Fatalf("failed to parse test trace: %v", err)
	}

	params := &traceParams{
		events:  events,
		endTime: int64(1<<63 - 1),
	}

	// If the counts drop below 0, generateTrace will return an error.
	viewerData, err := generateTrace(params)
	if err != nil {
		t.Fatalf("generateTrace failed: %v", err)
	}
	for _, ev := range viewerData.Events {
		if ev.Name == "Goroutines" {
			cnt := ev.Arg.(*goroutineCountersArg)
			if cnt.Runnable+cnt.Running > 2 {
				t.Errorf("goroutine count=%+v; want no more than 2 goroutines in runnable/running state", cnt)
			}
			t.Logf("read %+v %+v", ev, cnt)
		}
	}
}

func TestTrace(t *testing.T) {
	buf := new(bytes.Buffer)
	if err := Start(buf); err != nil {
		t.Fatalf("failed to start tracing: %v", err)
	}
	Stop()
	_, err := trace.Parse(buf)
	if err == trace.ErrTimeOrder {
		t.Skipf("skipping trace: %v", err)
	}
	if err != nil {
		t.Fatalf("failed to parse trace: %v", err)
	}
}

func parseTrace(t *testing.T, r io.Reader) ([]*trace.Event, map[uint64]*trace.GDesc) {
	events, err := trace.Parse(r, "")
	if err == trace.ErrTimeOrder {
		t.Skipf("skipping trace: %v", err)
	}
	if err != nil {
		t.Fatalf("failed to parse trace: %v", err)
	}
	gs := trace.GoroutineStats(events)
	for goid := range gs {
		// We don't do any particular checks on the result at the moment.
		// But still check that RelatedGoroutines does not crash, hang, etc.
		_ = trace.RelatedGoroutines(events, goid)
	}
	return events, gs
}

func parseEvents() ([]*trace.Event, error) {
	loader.once.Do(func() {
		tracef, err := os.Open(traceFile)
		if err != nil {
			loader.err = fmt.Errorf("failed to open trace file: %v", err)
			return
		}
		defer tracef.Close()

		// Parse and symbolize.
		events, err := trace.Parse(bufio.NewReader(tracef), programBinary)
		if err != nil {
			loader.err = fmt.Errorf("failed to parse trace: %v", err)
			return
		}
		loader.events = events
	})
	return loader.events, loader.err
}

func TestGoroutineFilter(t *testing.T) {
	// Test that we handle state changes to selected goroutines
	// caused by events on goroutines that are not selected.

	w := trace.NewWriter()
	w.Emit(trace.EvBatch, 0, 0)  // start of per-P batch event [pid, timestamp]
	w.Emit(trace.EvFrequency, 1) // [ticks per second]

	// goroutine 10: blocked
	w.Emit(trace.EvGoCreate, 1, 10, 1, 1) // [timestamp, new goroutine id, new stack id, stack id]
	w.Emit(trace.EvGoWaiting, 1, 10)      // [timestamp, goroutine id]

	// goroutine 20: runnable->running->unblock 10
	w.Emit(trace.EvGoCreate, 1, 20, 7, 1)
	w.Emit(trace.EvGoStartLocal, 1, 20)      // [timestamp, goroutine id]
	w.Emit(trace.EvGoUnblockLocal, 1, 10, 8) // [timestamp, goroutine id, stack]
	w.Emit(trace.EvGoEnd, 1)                 // [timestamp]

	// goroutine 10: runnable->running->block
	w.Emit(trace.EvGoStartLocal, 1, 10) // [timestamp, goroutine id]
	w.Emit(trace.EvGoBlock, 1, 9)       // [timestamp, stack]

	events, err := trace.Parse(w, "")
	if err != nil {
		t.Fatalf("failed to parse test trace: %v", err)
	}

	params := &traceParams{
		events:  events,
		endTime: int64(1<<63 - 1),
		gs:      map[uint64]bool{10: true},
	}

	_, err = generateTrace(params)
	if err != nil {
		t.Fatalf("generateTrace failed: %v", err)
	}
}

func testBrokenTimestamps(t *testing.T, data []byte) {
	// On some processors cputicks (used to generate trace timestamps)
	// produce non-monotonic timestamps. It is important that the parser
	// distinguishes logically inconsistent traces (e.g. missing, excessive
	// or misordered events) from broken timestamps. The former is a bug
	// in tracer, the latter is a machine issue.
	// So now that we have a consistent trace, test that (1) parser does
	// not return a logical error in case of broken timestamps
	// and (2) broken timestamps are eventually detected and reported.
	trace.BreakTimestampsForTesting = true
	defer func() {
		trace.BreakTimestampsForTesting = false
	}()
	for i := 0; i < 1e4; i++ {
		_, err := trace.Parse(bytes.NewReader(data), "")
		if err == trace.ErrTimeOrder {
			return
		}
		if err != nil {
			t.Fatalf("failed to parse trace: %v", err)
		}
	}
}