Keep the unit level within its bound: the counter test counts 400 not 2000, the deadline test waits 50 ms not 1 s (issue 895)

Both still prove what they did: the counter test still collides every run and fails when an increment
writes without its revision; the deadline test fails when the read after a failed write takes a later
deadline than the ask's.

go/cli/refusal_test.go

@@ -106,7 +106,7 @@ func TestAFailedWriteWaitsNoLongerThanTheDeadline(t *testing.T) {
 		default:
 		}
 	})
-	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
 	defer cancel()
 	start := time.Now()
 	_, err = Ask(ctx, socket, aLineTheSocketCannotHold())
@@ -117,7 +117,7 @@ func TestAFailedWriteWaitsNoLongerThanTheDeadline(t *testing.T) {
 	if !errors.Is(err, os.ErrDeadlineExceeded) {
 		t.Fatalf("the error is not the deadline: %v", err)
 	}
-	if waited > 3*time.Second {
-		t.Fatalf("waited %s with a deadline of 1s", waited)
+	if waited > time.Second {
+		t.Fatalf("waited %s with a deadline of 50ms", waited)
 	}
 }

go/state_counter_test.go

@@ -138,11 +138,11 @@ func text(t *testing.T, a map[string]any) (string, bool) {
 	return content[0].(map[string]any)["text"].(string), isError
 }
 
-// Two writers incrementing one counter a thousand times each end at two thousand: every number handed out
+// Two writers incrementing one counter two hundred times each end at four hundred: every number handed out
 // once, none lost, each writer's numbers rising — read, then written only at the revision read.
 func TestTwoWritersIncrementingOneCounterLoseNoUpdate(t *testing.T) {
 	r := &casRuntime{keys: map[string]StateEntry{}, writes: map[string]int{}}
-	const each = 1000
+	const each = 200 // enough to collide every run (about a third of writes are lost), cheap on a slow builder
 	got := counting(t, r, func() (any, error) {
 		var wg sync.WaitGroup
 		numbers := make([][]uint64, 2)
@@ -179,7 +179,7 @@ func TestTwoWritersIncrementingOneCounterLoseNoUpdate(t *testing.T) {
 		}
 		return len(seen), nil
 	})
-	if out, isError := text(t, got); isError || out != "2000" {
+	if out, isError := text(t, got); isError || out != fmt.Sprint(2*each) {
 		t.Fatalf("two writers counted %s (error: %v)", out, isError)
 	}
 	var final uint64
@@ -190,7 +190,7 @@ func TestTwoWritersIncrementingOneCounterLoseNoUpdate(t *testing.T) {
 	if r.lost == 0 {
 		t.Fatal("the two writers never collided: the test proved nothing about contention")
 	}
-	t.Logf("2000 increments, %d writes lost to the other writer and tried again", r.lost)
+	t.Logf("%d increments, %d writes lost to the other writer and tried again", 2*each, r.lost)
 	if r.writes["create"] != 1 || r.writes["update"] != 2*each-1 || r.writes["put"] != 0 {
 		t.Fatalf("written by %v: one create, then updates at the revision read, never a put", r.writes)
 	}