- first

cmd/main.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"log"
+	"os"
+	"time"
+
+	"github.com/chrispassas/peak"
+)
+
+func main() {
+	log.Printf("start")
+	log.Printf("pid:%d", os.Getpid())
+
+	// os.Stderr.Close()
+	os.Stdout.Close()
+	// os.Stdin.Close()
+
+	for x := 0; x < 10; x++ {
+		log.Printf("x:%d", x)
+		time.Sleep(time.Second * 2)
+		log.Printf("peak mem:%d", peak.PeakMemory())
+		log.Printf("peak goroutines:%d", peak.PeakGoRoutines())
+		log.Printf("peak fd:%d", peak.PeakFileHandles())
+	}
+
+	log.Printf("end")
+}

go.mod

@@ -0,0 +1,3 @@
+module github.com/chrispassas/peak
+
+go 1.18

peak.go

@@ -0,0 +1,108 @@
+package peak
+
+import (
+	"log"
+	"os"
+	"runtime"
+	"sync"
+	"time"
+)
+
+var m2 sync.RWMutex
+var interval = time.Second * 2
+
+var m sync.RWMutex
+var peakMemory uint64
+var peakGoRoutines uint64
+var peakFileDescriptors uint64
+
+func init() {
+	go update()
+}
+
+func update() {
+	for {
+		updatePeakMemory()
+		updatePeakGoroutines()
+		updateFileDescriptors()
+		m2.RLock()
+		time.Sleep(interval)
+		m2.RUnlock()
+	}
+}
+
+func updatePeakMemory() {
+	var mem runtime.MemStats
+	runtime.ReadMemStats(&mem)
+	m.Lock()
+	defer m.Unlock()
+	if mem.Alloc > peakMemory {
+		peakMemory = mem.Alloc
+	}
+}
+
+func updatePeakGoroutines() {
+	count := uint64(runtime.NumGoroutine())
+	m.Lock()
+	defer m.Unlock()
+	if count > peakGoRoutines {
+		peakGoRoutines = count
+	}
+}
+
+func updateFileDescriptors() {
+	var fdPath string
+	switch runtime.GOOS {
+	case "darwin":
+		fdPath = "/dev/fd"
+	case "linux", "freebsd":
+		fdPath = "/proc/self/fd"
+	default:
+		return
+	}
+
+	entries, err := os.ReadDir(fdPath)
+	log.Printf("fd count:%d error:%v", entries, err)
+	for _, e := range entries {
+		log.Printf("[DEBUG] name:%s type:%s", e.Name(), e.Type())
+	}
+	// files, _ := ioutil.ReadDir(fmt.Sprintf("/proc/%d/fd", pid))
+
+	m.Lock()
+	defer m.Unlock()
+	peakFileDescriptors = uint64(len(entries))
+}
+
+func PeakMemory() uint64 {
+	m.RLock()
+	defer m.RUnlock()
+	return peakMemory
+}
+
+func PeakGoRoutines() uint64 {
+	m.RLock()
+	defer m.RUnlock()
+	return peakGoRoutines
+}
+
+func PeakFileHandles() uint64 {
+	m.RLock()
+	defer m.RUnlock()
+	return peakFileDescriptors
+}
+
+func Reset() {
+	m.Lock()
+	defer m.Unlock()
+	peakMemory = 0
+	peakGoRoutines = 0
+	peakFileDescriptors = 0
+}
+
+func SetInterval(dur time.Duration) {
+	if dur > 0 {
+		m2.Lock()
+		interval = dur
+		m2.Unlock()
+	}
+}