| // Copyright 2006-2008 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| // |
| |
| #ifndef V8_HANDLES_INL_H_ |
| #define V8_HANDLES_INL_H_ |
| |
| #include "api.h" |
| #include "apiutils.h" |
| #include "handles.h" |
| #include "heap.h" |
| #include "isolate.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| template<typename T> |
| Handle<T>::Handle(T* obj) { |
| ASSERT(!obj->IsFailure()); |
| location_ = HandleScope::CreateHandle(obj->GetIsolate(), obj); |
| } |
| |
| |
| template<typename T> |
| Handle<T>::Handle(T* obj, Isolate* isolate) { |
| ASSERT(!obj->IsFailure()); |
| location_ = HandleScope::CreateHandle(isolate, obj); |
| } |
| |
| |
| template <typename T> |
| inline bool Handle<T>::is_identical_to(const Handle<T> other) const { |
| ASSERT(location_ == NULL || !(*location_)->IsFailure()); |
| if (location_ == other.location_) return true; |
| if (location_ == NULL || other.location_ == NULL) return false; |
| // Dereferencing deferred handles to check object equality is safe. |
| SLOW_ASSERT(IsDereferenceAllowed(NO_DEFERRED_CHECK) && |
| other.IsDereferenceAllowed(NO_DEFERRED_CHECK)); |
| return *location_ == *other.location_; |
| } |
| |
| |
| template <typename T> |
| inline T* Handle<T>::operator*() const { |
| ASSERT(location_ != NULL && !(*location_)->IsFailure()); |
| SLOW_ASSERT(IsDereferenceAllowed(INCLUDE_DEFERRED_CHECK)); |
| return *BitCast<T**>(location_); |
| } |
| |
| template <typename T> |
| inline T** Handle<T>::location() const { |
| ASSERT(location_ == NULL || !(*location_)->IsFailure()); |
| SLOW_ASSERT(location_ == NULL || |
| IsDereferenceAllowed(INCLUDE_DEFERRED_CHECK)); |
| return location_; |
| } |
| |
| #ifdef DEBUG |
| template <typename T> |
| bool Handle<T>::IsDereferenceAllowed(DereferenceCheckMode mode) const { |
| ASSERT(location_ != NULL); |
| Object* object = *BitCast<T**>(location_); |
| if (object->IsSmi()) return true; |
| HeapObject* heap_object = HeapObject::cast(object); |
| Heap* heap = heap_object->GetHeap(); |
| Object** handle = reinterpret_cast<Object**>(location_); |
| Object** roots_array_start = heap->roots_array_start(); |
| if (roots_array_start <= handle && |
| handle < roots_array_start + Heap::kStrongRootListLength && |
| heap->RootCanBeTreatedAsConstant( |
| static_cast<Heap::RootListIndex>(handle - roots_array_start))) { |
| return true; |
| } |
| if (!AllowHandleDereference::IsAllowed()) return false; |
| if (mode == INCLUDE_DEFERRED_CHECK && |
| !AllowDeferredHandleDereference::IsAllowed()) { |
| // Accessing maps and internalized strings is safe. |
| if (heap_object->IsMap()) return true; |
| if (heap_object->IsInternalizedString()) return true; |
| return !heap->isolate()->IsDeferredHandle(handle); |
| } |
| return true; |
| } |
| #endif |
| |
| |
| |
| HandleScope::HandleScope(Isolate* isolate) { |
| v8::ImplementationUtilities::HandleScopeData* current = |
| isolate->handle_scope_data(); |
| isolate_ = isolate; |
| prev_next_ = current->next; |
| prev_limit_ = current->limit; |
| current->level++; |
| } |
| |
| |
| HandleScope::~HandleScope() { |
| CloseScope(isolate_, prev_next_, prev_limit_); |
| } |
| |
| |
| void HandleScope::CloseScope(Isolate* isolate, |
| Object** prev_next, |
| Object** prev_limit) { |
| v8::ImplementationUtilities::HandleScopeData* current = |
| isolate->handle_scope_data(); |
| |
| current->next = prev_next; |
| current->level--; |
| if (current->limit != prev_limit) { |
| current->limit = prev_limit; |
| DeleteExtensions(isolate); |
| } |
| |
| #ifdef ENABLE_EXTRA_CHECKS |
| ZapRange(prev_next, prev_limit); |
| #endif |
| } |
| |
| |
| template <typename T> |
| Handle<T> HandleScope::CloseAndEscape(Handle<T> handle_value) { |
| v8::ImplementationUtilities::HandleScopeData* current = |
| isolate_->handle_scope_data(); |
| |
| T* value = *handle_value; |
| // Throw away all handles in the current scope. |
| CloseScope(isolate_, prev_next_, prev_limit_); |
| // Allocate one handle in the parent scope. |
| ASSERT(current->level > 0); |
| Handle<T> result(CreateHandle<T>(isolate_, value)); |
| // Reinitialize the current scope (so that it's ready |
| // to be used or closed again). |
| prev_next_ = current->next; |
| prev_limit_ = current->limit; |
| current->level++; |
| return result; |
| } |
| |
| |
| template <typename T> |
| T** HandleScope::CreateHandle(Isolate* isolate, T* value) { |
| ASSERT(AllowHandleAllocation::IsAllowed()); |
| v8::ImplementationUtilities::HandleScopeData* current = |
| isolate->handle_scope_data(); |
| |
| internal::Object** cur = current->next; |
| if (cur == current->limit) cur = Extend(isolate); |
| // Update the current next field, set the value in the created |
| // handle, and return the result. |
| ASSERT(cur < current->limit); |
| current->next = cur + 1; |
| |
| T** result = reinterpret_cast<T**>(cur); |
| *result = value; |
| return result; |
| } |
| |
| |
| #ifdef DEBUG |
| inline SealHandleScope::SealHandleScope(Isolate* isolate) : isolate_(isolate) { |
| // Make sure the current thread is allowed to create handles to begin with. |
| CHECK(AllowHandleAllocation::IsAllowed()); |
| v8::ImplementationUtilities::HandleScopeData* current = |
| isolate_->handle_scope_data(); |
| // Shrink the current handle scope to make it impossible to do |
| // handle allocations without an explicit handle scope. |
| limit_ = current->limit; |
| current->limit = current->next; |
| level_ = current->level; |
| current->level = 0; |
| } |
| |
| |
| inline SealHandleScope::~SealHandleScope() { |
| // Restore state in current handle scope to re-enable handle |
| // allocations. |
| v8::ImplementationUtilities::HandleScopeData* current = |
| isolate_->handle_scope_data(); |
| ASSERT_EQ(0, current->level); |
| current->level = level_; |
| ASSERT_EQ(current->next, current->limit); |
| current->limit = limit_; |
| } |
| |
| #endif |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_HANDLES_INL_H_ |