Golang runtime.ReadMemStats函数代码示例

func main() {
	cpus := runtime.NumCPU()
	runtime.GOMAXPROCS(cpus)

	count := 100000

	die := make(chan bool)

	var startMemory runtime.MemStats
	runtime.ReadMemStats(&startMemory)

	start := time.Now()
	for i := 0; i < count; i++ {
		go waitAround(die)
	}

	elapsed := time.Since(start)
	var endMemory runtime.MemStats
	runtime.ReadMemStats(&endMemory)

	fmt.Printf("Started %d goroutines on %d CPUs in %f seconds \n",
		count, cpus, elapsed.Seconds())

	fmt.Printf("Memory before %d, memory after %d \n",
		startMemory.Alloc, endMemory.Alloc)

	fmt.Printf("%d goroutines running\n", runtime.NumGoroutine())

	close(die)
}

// Check that reading large files doesn't lead to large allocations.
func TestReadLargeMemCheck(t *testing.T) {
	ts := NewTestCase(t)
	defer ts.Cleanup()

	content := RandomData(385 * 1023)
	err := ioutil.WriteFile(ts.origFile, []byte(content), 0644)
	if err != nil {
		t.Fatalf("WriteFile failed: %v", err)
	}

	f, err := os.Open(ts.mountFile)
	if err != nil {
		t.Fatalf("Open failed: %v", err)
	}
	buf := make([]byte, len(content)+1024)
	f.Read(buf)
	if err != nil {
		t.Fatalf("Read failed: %v", err)
	}
	f.Close()
	runtime.GC()
	var before, after runtime.MemStats

	N := 100
	runtime.ReadMemStats(&before)
	for i := 0; i < N; i++ {
		f, _ := os.Open(ts.mountFile)
		f.Read(buf)
		f.Close()
	}
	runtime.ReadMemStats(&after)
	delta := int((after.TotalAlloc - before.TotalAlloc))
	delta = (delta - 40000) / N
	t.Logf("bytes per read loop: %d", delta)
}

func (c *Corpus) UpdateIndex() {
	if c.Verbose {
		log.Printf("updating index...")
	}
	start := time.Now()
	throttle := c.IndexThrottle
	if throttle <= 0 {
		throttle = 0.9
	} else if throttle > 1.0 {
		throttle = 1.0
	}
	index := c.NewIndex()
	stop := time.Now()
	c.searchIndex.Set(index)
	if c.Verbose {
		secs := stop.Sub(start).Seconds()
		stats := index.Stats()
		log.Printf("index updated (%gs, %d bytes of source, %d files, %d lines, %d unique words, %d spots)",
			secs, stats.Bytes, stats.Files, stats.Lines, stats.Words, stats.Spots)
	}
	memstats := new(runtime.MemStats)
	runtime.ReadMemStats(memstats)
	if c.Verbose {
		log.Printf("before GC: bytes = %d footprint = %d", memstats.HeapAlloc, memstats.Sys)
	}
	runtime.GC()
	runtime.ReadMemStats(memstats)
	if c.Verbose {
		log.Printf("after  GC: bytes = %d footprint = %d", memstats.HeapAlloc, memstats.Sys)
	}
}

/*
Populates a trie structure with the contents of a text file that
has the provided name
*/
func PopulateTrie(file string) {
	trie = wordTrie.NewTrie()
	// Open the text file
	f, err := os.Open(file)
	//f, err := os.Open(file)
	check(err)

	// Begin scanning the text file line by line, populate the trie
	scanner := bufio.NewScanner(f)

	// Initial available memory read prior to entering the while loop
	runtime.ReadMemStats(&mem)
	currentMemory := mem.Alloc

	// Add entries to the trie as long as there is enough memory
	for scanner.Scan() && currentMemory < memoryLimit {
		runtime.ReadMemStats(&mem)
		currentMemory = mem.TotalAlloc
		trie.AddEntry(scanner.Text())
	}
	if err := scanner.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "reading standard input:", err)
	}
	f.Close()

	fmt.Println(trie.GetNumberOfItems()) //TESTING
}

func TestPeriodicGC(t *testing.T) {
	// Make sure we're not in the middle of a GC.
	runtime.GC()

	var ms1, ms2 runtime.MemStats
	runtime.ReadMemStats(&ms1)

	// Make periodic GC run continuously.
	orig := *runtime.ForceGCPeriod
	*runtime.ForceGCPeriod = 0

	// Let some periodic GCs happen. In a heavily loaded system,
	// it's possible these will be delayed, so this is designed to
	// succeed quickly if things are working, but to give it some
	// slack if things are slow.
	var numGCs uint32
	const want = 2
	for i := 0; i < 20 && numGCs < want; i++ {
		time.Sleep(5 * time.Millisecond)

		// Test that periodic GC actually happened.
		runtime.ReadMemStats(&ms2)
		numGCs = ms2.NumGC - ms1.NumGC
	}
	*runtime.ForceGCPeriod = orig

	if numGCs < want {
		t.Fatalf("no periodic GC: got %v GCs, want >= 2", numGCs)
	}
}

func BenchmarkExtract(b *testing.B) {
	config, err := ioutil.ReadFile("test/haproxy.csv")
	if err != nil {
		b.Fatalf("could not read config file: %v", err.Error())
	}

	h := newHaproxy(config)
	defer h.Close()

	e := NewExporter(h.URL, "", 5*time.Second)

	var before, after runtime.MemStats
	runtime.GC()
	runtime.ReadMemStats(&before)
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		ch := make(chan prometheus.Metric)
		go func(ch chan prometheus.Metric) {
			for _ = range ch {
			}
		}(ch)

		e.Collect(ch)
		close(ch)
	}

	runtime.GC()
	runtime.ReadMemStats(&after)

	b.Logf("%d bytes used after %d runs", after.Alloc-before.Alloc, b.N)
}

func (a *Adminz) gcHandler(w http.ResponseWriter, r *http.Request) {
	var mem runtime.MemStats

	mb := uint64(1024 * 1024)
	runtime.ReadMemStats(&mem)
	fmt.Fprintln(w, "Before")
	fmt.Fprintln(w, "\tAlloc\t", mem.Alloc/mb)
	fmt.Fprintln(w, "\tTotalAlloc:\t", mem.TotalAlloc/mb)
	fmt.Fprintln(w, "\tHeapAlloc:\t", mem.HeapAlloc/mb)
	fmt.Fprintln(w, "\tHeapSys:\t", mem.HeapSys/mb)
	fmt.Fprintln(w, "\tSys:\t", mem.Sys/mb)

	a.Lock()
	was := a.doPause()
	runtime.GC()
	if was {
		a.doResume()
	}
	a.Unlock()

	runtime.ReadMemStats(&mem)
	fmt.Fprintln(w, "After")
	fmt.Fprintln(w, "\tAlloc\t", mem.Alloc/mb)
	fmt.Fprintln(w, "\tTotalAlloc:\t", mem.TotalAlloc/mb)
	fmt.Fprintln(w, "\tHeapAlloc:\t", mem.HeapAlloc/mb)
	fmt.Fprintln(w, "\tHeapSys:\t", mem.HeapSys/mb)
	fmt.Fprintln(w, "\tSys:\t", mem.Sys/mb)

	w.Write([]byte("OK"))
}

func TestClean(t *testing.T) {
	tests := cleantests
	if runtime.GOOS == "windows" {
		for i := range tests {
			tests[i].result = filepath.FromSlash(tests[i].result)
		}
		tests = append(tests, wincleantests...)
	}
	for _, test := range tests {
		if s := filepath.Clean(test.path); s != test.result {
			t.Errorf("Clean(%q) = %q, want %q", test.path, s, test.result)
		}
		if s := filepath.Clean(test.result); s != test.result {
			t.Errorf("Clean(%q) = %q, want %q", test.result, s, test.result)
		}
	}

	var ms runtime.MemStats
	runtime.ReadMemStats(&ms)
	allocs := -ms.Mallocs
	const rounds = 100
	for i := 0; i < rounds; i++ {
		for _, test := range tests {
			filepath.Clean(test.result)
		}
	}
	runtime.ReadMemStats(&ms)
	allocs += ms.Mallocs
	if allocs >= rounds {
		t.Errorf("Clean cleaned paths: %d allocations per test round, want zero", allocs/rounds)
	}
}

func writeHeader(writer io.Writer) {
	fmt.Fprintf(writer, "Start time: %s<br>\n", startTime.Format(timeFormat))
	uptime := time.Since(startTime) + time.Millisecond*50
	uptime = (uptime / time.Millisecond / 100) * time.Millisecond * 100
	fmt.Fprintf(writer, "Uptime: %s<br>\n", uptime)
	var rusage syscall.Rusage
	syscall.Getrusage(syscall.RUSAGE_SELF, &rusage)
	userCpuTime := time.Duration(rusage.Utime.Sec)*time.Second +
		time.Duration(rusage.Utime.Usec)*time.Microsecond
	sysCpuTime := time.Duration(rusage.Stime.Sec)*time.Second +
		time.Duration(rusage.Stime.Usec)*time.Microsecond
	cpuTime := rusage.Utime.Sec + rusage.Stime.Sec
	fmt.Fprintf(writer, "CPU Time: %.1f%% (User: %s Sys: %s)<br>\n",
		float64(cpuTime*100)/float64(uptime.Seconds()), userCpuTime, sysCpuTime)
	var memStatsBeforeGC, memStatsAfterGC runtime.MemStats
	runtime.ReadMemStats(&memStatsBeforeGC)
	runtime.GC()
	runtime.ReadMemStats(&memStatsAfterGC)
	fmt.Fprintf(writer, "Allocated memory: %s (%s after GC)<br>\n",
		format.FormatBytes(memStatsBeforeGC.Alloc),
		format.FormatBytes(memStatsAfterGC.Alloc))
	fmt.Fprintf(writer, "System memory: %s (%s after GC)<br>\n",
		format.FormatBytes(memStatsBeforeGC.Sys),
		format.FormatBytes(memStatsAfterGC.Sys))
	fmt.Fprintln(writer, "Raw <a href=\"metrics\">metrics</a>")
}

func main() {
	cpus := runtime.NumCPU()
	runtime.GOMAXPROCS(cpus)
	count := 1000 * 100

	var startMemory runtime.MemStats
	runtime.ReadMemStats(&startMemory)

	start := time.Now()
	fin := make(chan bool)
	for i := 0; i < count; i++ {
		go func() {
			<-fin
		}()
	}
	elapsed := time.Since(start)

	var endMemory runtime.MemStats
	runtime.ReadMemStats(&endMemory)
	close(fin)

	fmt.Printf(`
goroutine:  %d
cpu:        %d
time:        %f
memory all: %f MB
memory:      %f byte/goroutine
`,
		count, cpus, elapsed.Seconds(),
		float64(endMemory.Alloc-startMemory.Alloc)/float64(1024*1024),
		float64(endMemory.Alloc-startMemory.Alloc)/float64(count))
}

func TestCountDecodeMallocs(t *testing.T) {
	var buf bytes.Buffer
	enc := NewEncoder(&buf)
	bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")}
	const count = 1000
	for i := 0; i < count; i++ {
		err := enc.Encode(bench)
		if err != nil {
			t.Fatal("encode:", err)
		}
	}
	dec := NewDecoder(&buf)
	memstats := new(runtime.MemStats)
	runtime.ReadMemStats(memstats)
	mallocs := 0 - memstats.Mallocs
	for i := 0; i < count; i++ {
		*bench = Bench{}
		err := dec.Decode(&bench)
		if err != nil {
			t.Fatal("decode:", err)
		}
	}
	runtime.ReadMemStats(memstats)
	mallocs += memstats.Mallocs
	fmt.Printf("mallocs per decode of type Bench: %d\n", mallocs/count)
}

func TestChunkReaderAllocs(t *testing.T) {
	// temporarily set GOMAXPROCS to 1 as we are testing memory allocations
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
	var buf bytes.Buffer
	w := newChunkedWriter(&buf)
	a, b, c := []byte("aaaaaa"), []byte("bbbbbbbbbbbb"), []byte("cccccccccccccccccccccccc")
	w.Write(a)
	w.Write(b)
	w.Write(c)
	w.Close()

	r := newChunkedReader(&buf)
	readBuf := make([]byte, len(a)+len(b)+len(c)+1)

	var ms runtime.MemStats
	runtime.ReadMemStats(&ms)
	m0 := ms.Mallocs

	n, err := io.ReadFull(r, readBuf)

	runtime.ReadMemStats(&ms)
	mallocs := ms.Mallocs - m0
	if mallocs > 1 {
		t.Errorf("%d mallocs; want <= 1", mallocs)
	}

	if n != len(readBuf)-1 {
		t.Errorf("read %d bytes; want %d", n, len(readBuf)-1)
	}
	if err != io.ErrUnexpectedEOF {
		t.Errorf("read error = %v; want ErrUnexpectedEOF", err)
	}
}

func BenchmarkExtract(b *testing.B) {
	config, err := ioutil.ReadFile("test/recursor_stats.json")
	if err != nil {
		b.Fatalf("could not read config file: %v", err.Error())
	}

	h := newPowerDNS(config)
	defer h.Close()

	hostURL, _ := url.Parse(h.URL)

	e := NewExporter("12345", "recursor", hostURL)

	var before, after runtime.MemStats
	runtime.GC()
	runtime.ReadMemStats(&before)
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		ch := make(chan prometheus.Metric)
		go func(ch chan prometheus.Metric) {
			for _ = range ch {
			}
		}(ch)

		e.Collect(ch)
		close(ch)
	}

	runtime.GC()
	runtime.ReadMemStats(&after)

	b.Logf("%d bytes used after %d runs", after.Alloc-before.Alloc, b.N)
}

// Cache memory leak for get
func testCacheGetMemoryLeak() {
	pc.OverrideLeaseSeconds(1)
	defer pc.OverrideLeaseSeconds(0)

	var memstats runtime.MemStats
	var initAlloc, midAlloc, finalAlloc uint64
	longValue := strings.Repeat("this sentence is 30 char long\n", 30)

	// Run garbage collection and get memory stats
	runtime.GC()
	runtime.ReadMemStats(&memstats)
	initAlloc = memstats.Alloc

	// Cache a lot of data
	for i := 0; i < 10000; i++ {
		key := fmt.Sprintf("keymemleakget:%d", i)
		pc.Reset()
		forceCacheGet(key, longValue)
		if pc.GetLeaseRequestCount() == 0 {
			LOGE.Println("FAIL: not requesting leases")
			failCount++
			return
		}
		pc.Reset()
		v, err := ls.Get(key)
		if checkError(err, false) {
			return
		}
		if v != longValue {
			LOGE.Println("FAIL: got wrong value")
			failCount++
			return
		}
		if pc.GetRpcCount() > 0 {
			LOGE.Println("FAIL: not caching data")
			failCount++
			return
		}
	}

	runtime.GC()
	runtime.ReadMemStats(&memstats)
	midAlloc = memstats.Alloc

	// Wait for data to expire and someone to cleanup
	time.Sleep(20 * time.Second)

	// Run garbage collection and get memory stats
	runtime.GC()
	runtime.ReadMemStats(&memstats)
	finalAlloc = memstats.Alloc

	if finalAlloc < initAlloc || (finalAlloc-initAlloc) < 5000000 {
		fmt.Fprintln(output, "PASS")
		passCount++
	} else {
		LOGE.Printf("FAIL: not cleaning cache - memory leak - init %d mid %d final %d\n", initAlloc, midAlloc, finalAlloc)
		failCount++
	}
}

func BenchmarkWatch(b *testing.B) {
	b.StopTimer()
	s := newStore()
	kvs, _ := generateNRandomKV(b.N, 128)
	b.StartTimer()

	memStats := new(runtime.MemStats)
	runtime.GC()
	runtime.ReadMemStats(memStats)

	for i := 0; i < b.N; i++ {
		w, _ := s.Watch(kvs[i][0], false, false, 0)

		e := newEvent("set", kvs[i][0], uint64(i+1), uint64(i+1))
		s.WatcherHub.notify(e)
		<-w.EventChan
		s.CurrentIndex++
	}

	s.WatcherHub.EventHistory = nil
	afterMemStats := new(runtime.MemStats)
	runtime.GC()
	runtime.ReadMemStats(afterMemStats)
	fmt.Printf("\nBefore Alloc: %v; After Alloc: %v\n",
		memStats.Alloc/1000, afterMemStats.Alloc/1000)
}