runtime: if InjectDebugCall sees "not at safe point", keep trying

Fixes #35376

Change-Id: Ib95ad336425e73cc4d412dafed0ba5e0a8130bd2
Reviewed-on: https://go-review.googlesource.com/c/go/+/205718
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

diff --git a/src/runtime/debug_test.go b/src/runtime/debug_test.go
index f77a373d1332fad2d66e740910908d9a42e006c3..722e81121f3f4e7e64f8e7257d76b289c7f5f86c 100644 (file)
--- a/src/runtime/debug_test.go
+++ b/src/runtime/debug_test.go
@@ -126,7 +126,7 @@ func TestDebugCall(t *testing.T) {
                return x + 1
        }
        args.x = 42
-       if _, err := runtime.InjectDebugCall(g, fn, &args, debugCallTKill); err != nil {
+       if _, err := runtime.InjectDebugCall(g, fn, &args, debugCallTKill, false); err != nil {
                t.Fatal(err)
        }
        if args.yRet != 43 {
@@ -155,7 +155,7 @@ func TestDebugCallLarge(t *testing.T) {
                args.in[i] = i
                want[i] = i + 1
        }
-       if _, err := runtime.InjectDebugCall(g, fn, &args, debugCallTKill); err != nil {
+       if _, err := runtime.InjectDebugCall(g, fn, &args, debugCallTKill, false); err != nil {
                t.Fatal(err)
        }
        if want != args.out {
@@ -168,7 +168,7 @@ func TestDebugCallGC(t *testing.T) {
        defer after()
 
        // Inject a call that performs a GC.
-       if _, err := runtime.InjectDebugCall(g, runtime.GC, nil, debugCallTKill); err != nil {
+       if _, err := runtime.InjectDebugCall(g, runtime.GC, nil, debugCallTKill, false); err != nil {
                t.Fatal(err)
        }
 }
@@ -179,7 +179,7 @@ func TestDebugCallGrowStack(t *testing.T) {
 
        // Inject a call that grows the stack. debugCallWorker checks
        // for stack pointer breakage.
-       if _, err := runtime.InjectDebugCall(g, func() { growStack(nil) }, nil, debugCallTKill); err != nil {
+       if _, err := runtime.InjectDebugCall(g, func() { growStack(nil) }, nil, debugCallTKill, false); err != nil {
                t.Fatal(err)
        }
 }
@@ -215,7 +215,7 @@ func TestDebugCallUnsafePoint(t *testing.T) {
                runtime.Gosched()
        }
 
-       _, err := runtime.InjectDebugCall(g, func() {}, nil, debugCallTKill)
+       _, err := runtime.InjectDebugCall(g, func() {}, nil, debugCallTKill, true)
        if msg := "call not at safe point"; err == nil || err.Error() != msg {
                t.Fatalf("want %q, got %s", msg, err)
        }
@@ -239,7 +239,7 @@ func TestDebugCallPanic(t *testing.T) {
        }()
        g := <-ready
 
-       p, err := runtime.InjectDebugCall(g, func() { panic("test") }, nil, debugCallTKill)
+       p, err := runtime.InjectDebugCall(g, func() { panic("test") }, nil, debugCallTKill, false)
        if err != nil {
                t.Fatal(err)
        }

diff --git a/src/runtime/export_debug_test.go b/src/runtime/export_debug_test.go
index 7deddd52ea9719c5d9a102f4f2846eabf009c1f6..7ae12f6da31c12ca5aa29a4afceaa4aef7d98af3 100644 (file)
--- a/src/runtime/export_debug_test.go
+++ b/src/runtime/export_debug_test.go
@@ -20,7 +20,7 @@ import (
 //
 // On success, InjectDebugCall returns the panic value of fn or nil.
 // If fn did not panic, its results will be available in args.
-func InjectDebugCall(gp *g, fn, args interface{}, tkill func(tid int) error) (interface{}, error) {
+func InjectDebugCall(gp *g, fn, args interface{}, tkill func(tid int) error, returnOnUnsafePoint bool) (interface{}, error) {
        if gp.lockedm == 0 {
                return nil, plainError("goroutine not locked to thread")
        }
@@ -64,6 +64,12 @@ func InjectDebugCall(gp *g, fn, args interface{}, tkill func(tid int) error) (in
                notetsleepg(&h.done, -1)
                if h.err != "" {
                        switch h.err {
+                       case "call not at safe point":
+                               if returnOnUnsafePoint {
+                                       // This is for TestDebugCallUnsafePoint.
+                                       return nil, h.err
+                               }
+                               fallthrough
                        case "retry _Grunnable", "executing on Go runtime stack":
                                // These are transient states. Try to get out of them.
                                if i < 100 {