v8/src/handles.cc
bmeurer d4f70f8ce8 [turbofan] Revive the VectorSlotPair and also put feedback on JSCallFunction.
We resurrect the VectorSlotPair in order to be able to separate the
feedback input for the compiler from the actual type feedback vector
that is required to meet the IC requirements at runtime. This will allow
us to for example use feedback from a different context or divide the
type feedback vector into two separate vectors, without having to touch
the compiler. It'll allow use to load the vector from the shared
function info at runtime, while still consuming feedback in the
compiler (i.e. we don't rely on the feedback vector node to be a heap
constant).

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/1198983002

Cr-Commit-Position: refs/heads/master@{#29185}
2015-06-22 12:08:20 +00:00

131 lines
3.9 KiB
C++

// Copyright 2012 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.
#include "src/v8.h"
#include "src/handles.h"
namespace v8 {
namespace internal {
int HandleScope::NumberOfHandles(Isolate* isolate) {
HandleScopeImplementer* impl = isolate->handle_scope_implementer();
int n = impl->blocks()->length();
if (n == 0) return 0;
return ((n - 1) * kHandleBlockSize) + static_cast<int>(
(isolate->handle_scope_data()->next - impl->blocks()->last()));
}
Object** HandleScope::Extend(Isolate* isolate) {
HandleScopeData* current = isolate->handle_scope_data();
Object** result = current->next;
DCHECK(result == current->limit);
// Make sure there's at least one scope on the stack and that the
// top of the scope stack isn't a barrier.
if (!Utils::ApiCheck(current->level != 0,
"v8::HandleScope::CreateHandle()",
"Cannot create a handle without a HandleScope")) {
return NULL;
}
HandleScopeImplementer* impl = isolate->handle_scope_implementer();
// If there's more room in the last block, we use that. This is used
// for fast creation of scopes after scope barriers.
if (!impl->blocks()->is_empty()) {
Object** limit = &impl->blocks()->last()[kHandleBlockSize];
if (current->limit != limit) {
current->limit = limit;
DCHECK(limit - current->next < kHandleBlockSize);
}
}
// If we still haven't found a slot for the handle, we extend the
// current handle scope by allocating a new handle block.
if (result == current->limit) {
// If there's a spare block, use it for growing the current scope.
result = impl->GetSpareOrNewBlock();
// Add the extension to the global list of blocks, but count the
// extension as part of the current scope.
impl->blocks()->Add(result);
current->limit = &result[kHandleBlockSize];
}
return result;
}
void HandleScope::DeleteExtensions(Isolate* isolate) {
HandleScopeData* current = isolate->handle_scope_data();
isolate->handle_scope_implementer()->DeleteExtensions(current->limit);
}
#ifdef ENABLE_HANDLE_ZAPPING
void HandleScope::ZapRange(Object** start, Object** end) {
DCHECK(end - start <= kHandleBlockSize);
for (Object** p = start; p != end; p++) {
*reinterpret_cast<Address*>(p) = v8::internal::kHandleZapValue;
}
}
#endif
Address HandleScope::current_level_address(Isolate* isolate) {
return reinterpret_cast<Address>(&isolate->handle_scope_data()->level);
}
Address HandleScope::current_next_address(Isolate* isolate) {
return reinterpret_cast<Address>(&isolate->handle_scope_data()->next);
}
Address HandleScope::current_limit_address(Isolate* isolate) {
return reinterpret_cast<Address>(&isolate->handle_scope_data()->limit);
}
DeferredHandleScope::DeferredHandleScope(Isolate* isolate)
: impl_(isolate->handle_scope_implementer()) {
impl_->BeginDeferredScope();
HandleScopeData* data = impl_->isolate()->handle_scope_data();
Object** new_next = impl_->GetSpareOrNewBlock();
Object** new_limit = &new_next[kHandleBlockSize];
DCHECK(data->limit == &impl_->blocks()->last()[kHandleBlockSize]);
impl_->blocks()->Add(new_next);
#ifdef DEBUG
prev_level_ = data->level;
#endif
data->level++;
prev_limit_ = data->limit;
prev_next_ = data->next;
data->next = new_next;
data->limit = new_limit;
}
DeferredHandleScope::~DeferredHandleScope() {
impl_->isolate()->handle_scope_data()->level--;
DCHECK(handles_detached_);
DCHECK(impl_->isolate()->handle_scope_data()->level == prev_level_);
}
DeferredHandles* DeferredHandleScope::Detach() {
DeferredHandles* deferred = impl_->Detach(prev_limit_);
HandleScopeData* data = impl_->isolate()->handle_scope_data();
data->next = prev_next_;
data->limit = prev_limit_;
#ifdef DEBUG
handles_detached_ = true;
#endif
return deferred;
}
} // namespace internal
} // namespace v8