node/deps/v8/test/mjsunit/compiler/deoptimize-lazy-weak.js
Ujjwal Sharma f579e11940 deps: update V8 to 7.4.288.13
PR-URL: https://github.com/nodejs/node/pull/26685
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
2019-03-28 16:36:18 -04:00

52 lines
1.4 KiB
JavaScript

// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --expose-gc --allow-natives-syntax --verify-heap
var o = { f : 0 };
var shouldDeopt = true;
// This tests a scenario where a function has an embedded object reference,
// the function is lazy-deoptimized, the object is then collected, but the
// code object keeps the dangling pointer.
function deopt() {
if (shouldDeopt) {
// Change the global object. This deoptimizes function f because
// it optimistically embedded the reference to o as a constant.
o = { f : 2 };
// Collect the original object o; at this point, f should invalidate
// its invalid reference to the original object.
gc();
}
}
// Forwarding function to make sure that function f is not the topomost
// optimized frame (GC treats reference from topmost optimized code strongly).
function dummy_opt() { deopt(); }
function dummy() { dummy_opt(); }
%NeverOptimizeFunction(deopt);
%NeverOptimizeFunction(dummy);
// When optimized, the function f embeds the constant reference
// to the original object o.
function f() {
dummy();
return o.f;
}
shouldDeopt = false;
%PrepareFunctionForOptimization(dummy_opt);
f();
f();
%OptimizeFunctionOnNextCall(dummy_opt);
f();
%PrepareFunctionForOptimization(f);
f();
%OptimizeFunctionOnNextCall(f);
shouldDeopt = true;
assertEquals(2, f());