1 files changed, 58 insertions, 16 deletions

diff --git a/src/runtime/pprof/pprof_test.go b/src/runtime/pprof/pprof_test.go
index 1ade860441..9480240615 100644
--- a/src/runtime/pprof/pprof_test.go
+++ b/src/runtime/pprof/pprof_test.go
@@ -1023,7 +1023,7 @@ func containsStack(got [][]string, want []string) bool {
 // awaitBlockedGoroutine spins on runtime.Gosched until a runtime stack dump
 // shows a goroutine in the given state with a stack frame in
 // runtime/pprof.<fName>.
-func awaitBlockedGoroutine(t *testing.T, state, fName string) {
+func awaitBlockedGoroutine(t *testing.T, state, fName string, count int) {
 	re := fmt.Sprintf(`(?m)^goroutine \d+ \[%s\]:\n(?:.+\n\t.+\n)*runtime/pprof\.%s`, regexp.QuoteMeta(state), fName)
 	r := regexp.MustCompile(re)
 
@@ -1047,7 +1047,7 @@ func awaitBlockedGoroutine(t *testing.T, state, fName string) {
 			buf = make([]byte, 2*len(buf))
 			continue
 		}
-		if r.Match(buf[:n]) {
+		if len(r.FindAll(buf[:n], -1)) >= count {
 			return
 		}
 	}
@@ -1056,7 +1056,7 @@ func awaitBlockedGoroutine(t *testing.T, state, fName string) {
 func blockChanRecv(t *testing.T) {
 	c := make(chan bool)
 	go func() {
-		awaitBlockedGoroutine(t, "chan receive", "blockChanRecv")
+		awaitBlockedGoroutine(t, "chan receive", "blockChanRecv", 1)
 		c <- true
 	}()
 	<-c
@@ -1065,7 +1065,7 @@ func blockChanRecv(t *testing.T) {
 func blockChanSend(t *testing.T) {
 	c := make(chan bool)
 	go func() {
-		awaitBlockedGoroutine(t, "chan send", "blockChanSend")
+		awaitBlockedGoroutine(t, "chan send", "blockChanSend", 1)
 		<-c
 	}()
 	c <- true
@@ -1074,7 +1074,7 @@ func blockChanSend(t *testing.T) {
 func blockChanClose(t *testing.T) {
 	c := make(chan bool)
 	go func() {
-		awaitBlockedGoroutine(t, "chan receive", "blockChanClose")
+		awaitBlockedGoroutine(t, "chan receive", "blockChanClose", 1)
 		close(c)
 	}()
 	<-c
@@ -1086,7 +1086,7 @@ func blockSelectRecvAsync(t *testing.T) {
 	c2 := make(chan bool, 1)
 	go func() {
 		for i := 0; i < numTries; i++ {
-			awaitBlockedGoroutine(t, "select", "blockSelectRecvAsync")
+			awaitBlockedGoroutine(t, "select", "blockSelectRecvAsync", 1)
 			c <- true
 		}
 	}()
@@ -1102,7 +1102,7 @@ func blockSelectSendSync(t *testing.T) {
 	c := make(chan bool)
 	c2 := make(chan bool)
 	go func() {
-		awaitBlockedGoroutine(t, "select", "blockSelectSendSync")
+		awaitBlockedGoroutine(t, "select", "blockSelectSendSync", 1)
 		<-c
 	}()
 	select {
@@ -1115,7 +1115,7 @@ func blockMutex(t *testing.T) {
 	var mu sync.Mutex
 	mu.Lock()
 	go func() {
-		awaitBlockedGoroutine(t, "sync.Mutex.Lock", "blockMutex")
+		awaitBlockedGoroutine(t, "sync.Mutex.Lock", "blockMutex", 1)
 		mu.Unlock()
 	}()
 	// Note: Unlock releases mu before recording the mutex event,
@@ -1125,12 +1125,36 @@ func blockMutex(t *testing.T) {
 	mu.Lock()
 }
 
+func blockMutexN(t *testing.T, n int, d time.Duration) {
+	var wg sync.WaitGroup
+	var mu sync.Mutex
+	mu.Lock()
+	go func() {
+		awaitBlockedGoroutine(t, "sync.Mutex.Lock", "blockMutex", n)
+		time.Sleep(d)
+		mu.Unlock()
+	}()
+	// Note: Unlock releases mu before recording the mutex event,
+	// so it's theoretically possible for this to proceed and
+	// capture the profile before the event is recorded. As long
+	// as this is blocked before the unlock happens, it's okay.
+	for i := 0; i < n; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			mu.Lock()
+			mu.Unlock()
+		}()
+	}
+	wg.Wait()
+}
+
 func blockCond(t *testing.T) {
 	var mu sync.Mutex
 	c := sync.NewCond(&mu)
 	mu.Lock()
 	go func() {
-		awaitBlockedGoroutine(t, "sync.Cond.Wait", "blockCond")
+		awaitBlockedGoroutine(t, "sync.Cond.Wait", "blockCond", 1)
 		mu.Lock()
 		c.Signal()
 		mu.Unlock()
@@ -1217,7 +1241,11 @@ func TestMutexProfile(t *testing.T) {
 		t.Fatalf("need MutexProfileRate 0, got %d", old)
 	}
 
-	blockMutex(t)
+	const (
+		N = 100
+		D = 100 * time.Millisecond
+	)
+	blockMutexN(t, N, D)
 
 	t.Run("debug=1", func(t *testing.T) {
 		var w strings.Builder
@@ -1230,15 +1258,11 @@ func TestMutexProfile(t *testing.T) {
 		}
 		prof = strings.Trim(prof, "\n")
 		lines := strings.Split(prof, "\n")
-		if len(lines) != 6 {
-			t.Errorf("expected 6 lines, got %d %q\n%s", len(lines), prof, prof)
-		}
 		if len(lines) < 6 {
-			return
+			t.Fatalf("expected >=6 lines, got %d %q\n%s", len(lines), prof, prof)
 		}
 		// checking that the line is like "35258904 1 @ 0x48288d 0x47cd28 0x458931"
 		r2 := `^\d+ \d+ @(?: 0x[[:xdigit:]]+)+`
-		//r2 := "^[0-9]+ 1 @ 0x[0-9a-f x]+$"
 		if ok, err := regexp.MatchString(r2, lines[3]); err != nil || !ok {
 			t.Errorf("%q didn't match %q", lines[3], r2)
 		}
@@ -1263,12 +1287,30 @@ func TestMutexProfile(t *testing.T) {
 
 		stks := stacks(p)
 		for _, want := range [][]string{
-			{"sync.(*Mutex).Unlock", "runtime/pprof.blockMutex.func1"},
+			{"sync.(*Mutex).Unlock", "runtime/pprof.blockMutexN.func1"},
 		} {
 			if !containsStack(stks, want) {
 				t.Errorf("No matching stack entry for %+v", want)
 			}
 		}
+
+		i := 0
+		for ; i < len(p.SampleType); i++ {
+			if p.SampleType[i].Unit == "nanoseconds" {
+				break
+			}
+		}
+		if i >= len(p.SampleType) {
+			t.Fatalf("profile did not contain nanoseconds sample")
+		}
+		total := int64(0)
+		for _, s := range p.Sample {
+			total += s.Value[i]
+		}
+		d := time.Duration(total)
+		if d < N*D*9/10 || d > N*D*2 { // want N*D but allow [0.9,2.0]*that.
+			t.Fatalf("profile samples total %v, want %v", d, N*D)
+		}
 	})
 }