d59db06bf5
Bug: v8:8179 Change-Id: I7f699073807d1874d0c10a4f1641de6bfb0efe6f Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2741582 Commit-Queue: Shu-yu Guo <syg@chromium.org> Reviewed-by: Shu-yu Guo <syg@chromium.org> Reviewed-by: Adam Klein <adamk@chromium.org> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org> Cr-Commit-Position: refs/heads/master@{#73871}
54 lines
1.7 KiB
JavaScript
54 lines
1.7 KiB
JavaScript
// Copyright 2020 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: --allow-natives-syntax --expose-gc
|
|
|
|
// Helper to convert setTimeout into an awaitable promise.
|
|
function asyncTimeout(timeout) {
|
|
return new Promise((resolve, reject)=>{
|
|
setTimeout(resolve, timeout);
|
|
})
|
|
}
|
|
|
|
function Foo() {}
|
|
|
|
function getX(o) { return o.x; }
|
|
|
|
(async function() {
|
|
let o = new Foo();
|
|
// Transition o:Foo to o:Foo{x}. This transition is important, as the o:Foo
|
|
// map is the initial map for the Foo constructor, and so is strongly held by
|
|
// it. We want o to be the only strong holder of its map.
|
|
o.x = 42;
|
|
%CompleteInobjectSlackTracking(new Foo());
|
|
|
|
// Warm up 'getX' with 'Foo{x}' feedback for its o.x access.
|
|
%PrepareFunctionForOptimization(getX);
|
|
assertEquals(getX(o), 42);
|
|
assertEquals(getX(o), 42);
|
|
|
|
// Clear out 'o', which is the only strong holder of the Foo{x} map.
|
|
let weak_o = new WeakRef(o);
|
|
o = null;
|
|
|
|
// Tick the message loop so that the weak ref can be collected.
|
|
await asyncTimeout(0);
|
|
|
|
// Collect the old 'o', which will also collect the 'Foo{x}' map.
|
|
gc();
|
|
|
|
// Make sure the old 'o' was collected.
|
|
assertEquals(undefined, weak_o.deref());
|
|
|
|
// Optimize the function with the current monomorphic 'Foo{x}' map o.x access,
|
|
// where the 'Foo{x}' map is dead and therefore the map set is empty. Then,
|
|
// create a new 'Foo{x}' object and pass that through. This compilation and
|
|
// o.x access should still succeed despite the dead map.
|
|
%OptimizeFunctionOnNextCall(getX);
|
|
o = new Foo();
|
|
o.x = 42;
|
|
assertEquals(getX(o), 42);
|
|
|
|
})();
|