blob: cf1e132c5f4035fc096d50d8b2917380a54deec7 [file] [log] [blame]
// Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/weak_code.h"
#include "platform/assert.h"
#include "vm/code_generator.h"
#include "vm/code_patcher.h"
#include "vm/compiler.h"
#include "vm/object.h"
#include "vm/stack_frame.h"
namespace dart {
void WeakCodeReferences::Register(const Code& value) {
if (!array_.IsNull()) {
// Try to find and reuse cleared WeakProperty to avoid allocating new one.
WeakProperty& weak_property = WeakProperty::Handle();
for (intptr_t i = 0; i < array_.Length(); i++) {
weak_property ^= array_.At(i);
if (weak_property.key() == Code::null()) {
// Empty property found. Reuse it.
weak_property.set_key(value);
return;
}
}
}
const WeakProperty& weak_property = WeakProperty::Handle(
WeakProperty::New(Heap::kOld));
weak_property.set_key(value);
intptr_t length = array_.IsNull() ? 0 : array_.Length();
const Array& new_array = Array::Handle(
Array::Grow(array_, length + 1, Heap::kOld));
new_array.SetAt(length, weak_property);
UpdateArrayTo(new_array);
}
bool WeakCodeReferences::IsOptimizedCode(const Array& dependent_code,
const Code& code) {
if (!code.is_optimized()) {
return false;
}
WeakProperty& weak_property = WeakProperty::Handle();
for (intptr_t i = 0; i < dependent_code.Length(); i++) {
weak_property ^= dependent_code.At(i);
if (code.raw() == weak_property.key()) {
return true;
}
}
return false;
}
void WeakCodeReferences::DisableCode() {
const Array& code_objects = Array::Handle(array_.raw());
if (code_objects.IsNull()) {
return;
}
ASSERT(Compiler::allow_recompilation());
UpdateArrayTo(Object::null_array());
// Disable all code on stack.
Code& code = Code::Handle();
{
DartFrameIterator iterator;
StackFrame* frame = iterator.NextFrame();
while (frame != NULL) {
code = frame->LookupDartCode();
if (IsOptimizedCode(code_objects, code)) {
ReportDeoptimization(code);
DeoptimizeAt(code, frame->pc());
}
frame = iterator.NextFrame();
}
}
// Switch functions that use dependent code to unoptimized code.
WeakProperty& weak_property = WeakProperty::Handle();
Object& owner = Object::Handle();
Function& function = Function::Handle();
for (intptr_t i = 0; i < code_objects.Length(); i++) {
weak_property ^= code_objects.At(i);
code ^= weak_property.key();
if (code.IsNull()) {
// Code was garbage collected already.
continue;
}
owner = code.owner();
if (owner.IsFunction()) {
function ^= owner.raw();
} else if (owner.IsClass()) {
Class& cls = Class::Handle();
cls ^= owner.raw();
OS::Print("Skipping code owned by class %s\n", cls.ToCString());
cls.DisableAllocationStub();
continue;
} else if (owner.IsNull()) {
OS::Print("Skipping code owned by null: ");
code.Print();
continue;
}
// If function uses dependent code switch it to unoptimized.
if (code.is_optimized() && (function.CurrentCode() == code.raw())) {
ReportSwitchingCode(code);
function.SwitchToUnoptimizedCode();
} else if (function.unoptimized_code() == code.raw()) {
ReportSwitchingCode(code);
function.ClearICDataArray();
// Remove the code object from the function. The next time the
// function is invoked, it will be compiled again.
function.ClearCode();
// Invalidate the old code object so existing references to it
// (from optimized code) will be patched when invoked.
if (!code.IsDisabled()) {
code.DisableDartCode();
}
} else {
// Make non-OSR code non-entrant.
if (!code.IsDisabled()) {
ReportSwitchingCode(code);
code.DisableDartCode();
}
}
}
}
} // namespace dart