runtime: resolve #52093

src/runtime/debug.go

@@ -9,6 +9,15 @@ import (
 	"unsafe"
 )
 
+// TracebackAncestors sets the limits the number of ancestor goroutines to report.
+// It extends tracebacks with the stacks at	which goroutines were created.
+// This also extends the information returned by runtime.Stack. Ancestor's goroutine
+// IDs will refer to the ID of the goroutine at the time of creation; it's possible for this
+// ID to be reused for another goroutine. Setting N to 0 will report no ancestry information.
+func TracebackAncestors(n int32) {
+	debug.tracebackancestors = n
+}
+
 // GOMAXPROCS sets the maximum number of CPUs that can be executing
 // simultaneously and returns the previous setting. It defaults to
 // the value of runtime.NumCPU. If n < 1, it does not change the current setting.

src/runtime/stack_test.go

@@ -802,6 +802,37 @@ func TestTracebackAncestors(t *testing.T) {
 	}
 }
 
+func TestSetTracebackAncestors(t *testing.T) {
+	wait := make(chan struct{})
+
+	go func() {
+		<-wait
+	}()
+
+	TracebackAncestors(3)
+	t.Cleanup(func() {
+		TracebackAncestors(0)
+	})
+
+	// GetStack of current runtime
+	getStack := func() string {
+		for i := 1024; ; i *= 2 {
+			buf := make([]byte, i)
+			if n := Stack(buf, true); n < i {
+				return string(buf[:n-1])
+			}
+		}
+	}
+
+	output := getStack()
+
+	if !strings.Contains(output, "originating from goroutine") {
+		t.Errorf("output does not contain ancestor trace:\n%s", output)
+	}
+
+	close(wait)
+}
+
 // Test that defer closure is correctly scanned when the stack is scanned.
 func TestDeferLiveness(t *testing.T) {
 	output := runTestProg(t, "testprog", "DeferLiveness", "GODEBUG=clobberfree=1")