runtime: remove arbitrary timeouts in finalizer tests

These short timeouts can overrun due to system scheduling delay
(or GC latency) on a slow or heavily-loaded host.

Moreover, if the test deadlocks we will probably want to know what the
GC goroutines were doing at the time. With an arbitrary timeout, we
never get that information; however, if we allow the test to time out
completely we will get a goroutine dump (and, if GOTRACEBACK is
configured in the environment, that may even include GC goroutines).

Fixes #57166.

Change-Id: I136501883373c3ce4e250dc8340c60876b375f44
Reviewed-on: https://go-review.googlesource.com/c/go/+/456118
Auto-Submit: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

1 files changed, 5 insertions, 21 deletions

diff --git a/src/runtime/mfinal_test.go b/src/runtime/mfinal_test.go
index 902ccc57f8..61d625ac27 100644
--- a/src/runtime/mfinal_test.go
+++ b/src/runtime/mfinal_test.go
@@ -53,7 +53,7 @@ func TestFinalizerType(t *testing.T) {
 		}},
 	}
 
-	for i, tt := range finalizerTests {
+	for _, tt := range finalizerTests {
 		done := make(chan bool, 1)
 		go func() {
 			// allocate struct with pointer to avoid hitting tinyalloc.
@@ -71,11 +71,7 @@ func TestFinalizerType(t *testing.T) {
 		}()
 		<-done
 		runtime.GC()
-		select {
-		case <-ch:
-		case <-time.After(time.Second * 4):
-			t.Errorf("#%d: finalizer for type %T didn't run", i, tt.finalizer)
-		}
+		<-ch
 	}
 }
 
@@ -109,11 +105,7 @@ func TestFinalizerInterfaceBig(t *testing.T) {
 	}()
 	<-done
 	runtime.GC()
-	select {
-	case <-ch:
-	case <-time.After(4 * time.Second):
-		t.Errorf("finalizer for type *bigValue didn't run")
-	}
+	<-ch
 }
 
 func fin(v *int) {
@@ -188,11 +180,7 @@ func TestEmptySlice(t *testing.T) {
 	fin := make(chan bool, 1)
 	runtime.SetFinalizer(y, func(z *objtype) { fin <- true })
 	runtime.GC()
-	select {
-	case <-fin:
-	case <-time.After(4 * time.Second):
-		t.Errorf("finalizer of next object in memory didn't run")
-	}
+	<-fin
 	xsglobal = xs // keep empty slice alive until here
 }
 
@@ -220,11 +208,7 @@ func TestEmptyString(t *testing.T) {
 	// set finalizer on string contents of y
 	runtime.SetFinalizer(y, func(z *objtype) { fin <- true })
 	runtime.GC()
-	select {
-	case <-fin:
-	case <-time.After(4 * time.Second):
-		t.Errorf("finalizer of next string in memory didn't run")
-	}
+	<-fin
 	ssglobal = ss // keep 0-length string live until here
 }