v8/test/debugger/debug/lazy-deopt-then-flush-bytecode.js
Mythri A ef7d657960 [sparkplug] Add support to flush only baseline code
Add support to flush only baseline code. FLAG_flush_baseline_code
controls if baseline code is flushed or not and FLAG_flush_bytecode
controls if bytecode is flushed or not. With this CL it is possible
to control if we want to flush only bytecode / only baseline code / both.
This also lets us have different heuristics for bytecode and baseline
code flushing.

Bug: v8:11947
Change-Id: Ibdfb9d8be7e7d54196db7890541fa0b5d84f037e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3060481
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76075}
2021-08-04 08:22:18 +00:00

50 lines
1.6 KiB
JavaScript

// Copyright 2018 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 --opt --noalways-opt --stress-flush-code
// Flags: --expose-gc --flush-bytecode
Debug = debug.Debug
function foo() {
return 44;
}
function listener(event, exec_state, event_data, data) {
if (event != Debug.DebugEvent.Break) return;
// Optimize foo.
%PrepareFunctionForOptimization(foo);
%OptimizeFunctionOnNextCall(foo);
foo();
assertOptimized(foo);
// Lazily deopt foo, which marks the code for deoptimization and invalidates
// the DeoptimizationData, but doesn't unlink the optimized code entry in
// foo's JSFunction.
%DeoptimizeFunction(foo);
// Run the GC. Since the DeoptimizationData is now dead, the bytecode
// associated with the optimized code is free to be flushed, which also
// free's the feedback vector meta-data.
gc();
// Execute foo with side-effect checks, which causes the debugger to call
// DeoptimizeFunction on foo. Even though the code is already marked for
// deoptimization, this will try to unlink the optimized code from the
// feedback vector, which will fail due to the feedback meta-data being
// flushed. The deoptimizer should call JSFunction::ResetIfBytecodeFlushed
// before trying to do this, which will clear the whole feedback vector and
// reset the JSFunction's code entry field to CompileLazy.
exec_state.frame(0).evaluate("foo()", true);
}
// Add the debug event listener.
Debug.setListener(listener);
function f() {
debugger;
}
f();