Commit 64e7c6b1 authored by sanjoy@chromium.org's avatar sanjoy@chromium.org

Add a second kind of HandleScope that ties the lifetime of Handles created in...

Add a second kind of HandleScope that ties the lifetime of Handles created in its scope to the lifetime of a given CompilationInfo.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/10640012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11939 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
parent 86231b85
......@@ -6374,12 +6374,28 @@ char* HandleScopeImplementer::RestoreThread(char* storage) {
void HandleScopeImplementer::IterateThis(ObjectVisitor* v) {
#ifdef DEBUG
bool found_block_before_deferred = false;
#endif
// Iterate over all handles in the blocks except for the last.
for (int i = blocks()->length() - 2; i >= 0; --i) {
Object** block = blocks()->at(i);
v->VisitPointers(block, &block[kHandleBlockSize]);
if (last_handle_before_deferred_block_ != NULL &&
(last_handle_before_deferred_block_ < &block[kHandleBlockSize]) &&
(last_handle_before_deferred_block_ >= block)) {
v->VisitPointers(block, last_handle_before_deferred_block_);
ASSERT(!found_block_before_deferred);
#ifdef DEBUG
found_block_before_deferred = true;
#endif
} else {
v->VisitPointers(block, &block[kHandleBlockSize]);
}
}
ASSERT(last_handle_before_deferred_block_ == NULL ||
found_block_before_deferred);
// Iterate over live handles in the last block (if any).
if (!blocks()->is_empty()) {
v->VisitPointers(blocks()->last(), handle_scope_data_.next);
......@@ -6389,6 +6405,12 @@ void HandleScopeImplementer::IterateThis(ObjectVisitor* v) {
Object** start = reinterpret_cast<Object**>(&saved_contexts_.first());
v->VisitPointers(start, start + saved_contexts_.length());
}
for (DeferredHandles* deferred = deferred_handles_head_;
deferred != NULL;
deferred = deferred->next_) {
deferred->Iterate(v);
}
}
......@@ -6407,4 +6429,75 @@ char* HandleScopeImplementer::Iterate(ObjectVisitor* v, char* storage) {
return storage + ArchiveSpacePerThread();
}
DeferredHandles* HandleScopeImplementer::Detach(Object** prev_limit) {
DeferredHandles* deferred = new DeferredHandles(
deferred_handles_head_, isolate()->handle_scope_data()->next, this);
while (!blocks_.is_empty()) {
Object** block_start = blocks_.last();
Object** block_limit = &block_start[kHandleBlockSize];
// We should not need to check for NoHandleAllocation here. Assert
// this.
ASSERT(prev_limit == block_limit ||
!(block_start <= prev_limit && prev_limit <= block_limit));
if (prev_limit == block_limit) break;
deferred->blocks_.Add(blocks_.last());
blocks_.RemoveLast();
}
ASSERT(!blocks_.is_empty() && prev_limit != NULL);
deferred_handles_head_ = deferred;
ASSERT(last_handle_before_deferred_block_ != NULL);
last_handle_before_deferred_block_ = NULL;
return deferred;
}
void HandleScopeImplementer::DestroyDeferredHandles(DeferredHandles* deferred) {
if (deferred_handles_head_ == deferred) {
deferred_handles_head_ = deferred_handles_head_->next_;
}
if (deferred->next_ != NULL) {
deferred->next_->previous_ = deferred->previous_;
}
if (deferred->previous_ != NULL) {
deferred->previous_->next_ = deferred->next_;
}
for (int i = 0; i < deferred->blocks_.length(); i++) {
#ifdef DEBUG
HandleScope::ZapRange(deferred->blocks_[i],
&deferred->blocks_[i][kHandleBlockSize]);
#endif
if (spare_ != NULL) DeleteArray(spare_);
spare_ = deferred->blocks_[i];
}
}
void HandleScopeImplementer::BeginDeferredScope() {
ASSERT(last_handle_before_deferred_block_ == NULL);
last_handle_before_deferred_block_ = isolate()->handle_scope_data()->next;
}
DeferredHandles::~DeferredHandles() {
impl_->DestroyDeferredHandles(this);
}
void DeferredHandles::Iterate(ObjectVisitor* v) {
ASSERT(!blocks_.is_empty());
for (int i = 0; i < (blocks_.length() - 1); i++) {
v->VisitPointers(blocks_[i], &blocks_[i][kHandleBlockSize]);
}
ASSERT((last_block_limit_ >= blocks_.last()) &&
(last_block_limit_ < &(blocks_.last())[kHandleBlockSize]));
v->VisitPointers(blocks_.last(), last_block_limit_);
}
} } // namespace v8::internal
......@@ -392,6 +392,28 @@ class StringTracker {
};
class DeferredHandles {
public:
~DeferredHandles();
private:
DeferredHandles(DeferredHandles* next, Object** last_block_limit,
HandleScopeImplementer* impl)
: next_(next), previous_(NULL), last_block_limit_(last_block_limit),
impl_(impl) {}
void Iterate(ObjectVisitor* v);
List<Object**> blocks_;
DeferredHandles* next_;
DeferredHandles* previous_;
Object** last_block_limit_;
HandleScopeImplementer* impl_;
friend class HandleScopeImplementer;
};
// This class is here in order to be able to declare it a friend of
// HandleScope. Moving these methods to be members of HandleScope would be
// neat in some ways, but it would expose internal implementation details in
......@@ -409,7 +431,9 @@ class HandleScopeImplementer {
entered_contexts_(0),
saved_contexts_(0),
spare_(NULL),
call_depth_(0) { }
call_depth_(0),
last_handle_before_deferred_block_(NULL),
deferred_handles_head_(NULL) { }
~HandleScopeImplementer() {
DeleteArray(spare_);
......@@ -445,6 +469,7 @@ class HandleScopeImplementer {
inline bool HasSavedContexts();
inline List<internal::Object**>* blocks() { return &blocks_; }
Isolate* isolate() const { return isolate_; }
private:
void ResetAfterArchive() {
......@@ -469,6 +494,10 @@ class HandleScopeImplementer {
ASSERT(call_depth_ == 0);
}
void BeginDeferredScope();
DeferredHandles* Detach(Object** prev_limit);
void DestroyDeferredHandles(DeferredHandles* handles);
Isolate* isolate_;
List<internal::Object**> blocks_;
// Used as a stack to keep track of entered contexts.
......@@ -477,6 +506,8 @@ class HandleScopeImplementer {
List<Context*> saved_contexts_;
Object** spare_;
int call_depth_;
Object** last_handle_before_deferred_block_;
DeferredHandles* deferred_handles_head_;
// This is only used for threading support.
v8::ImplementationUtilities::HandleScopeData handle_scope_data_;
......@@ -484,6 +515,9 @@ class HandleScopeImplementer {
char* RestoreThreadHelper(char* from);
char* ArchiveThreadHelper(char* to);
friend class DeferredHandles;
friend class DeferredHandleScope;
DISALLOW_COPY_AND_ASSIGN(HandleScopeImplementer);
};
......
......@@ -61,7 +61,8 @@ CompilationInfo::CompilationInfo(Handle<Script> script, Zone* zone)
extension_(NULL),
pre_parse_data_(NULL),
osr_ast_id_(AstNode::kNoNumber),
zone_(zone) {
zone_(zone),
deferred_handles_(NULL) {
Initialize(BASE);
}
......@@ -79,7 +80,8 @@ CompilationInfo::CompilationInfo(Handle<SharedFunctionInfo> shared_info,
extension_(NULL),
pre_parse_data_(NULL),
osr_ast_id_(AstNode::kNoNumber),
zone_(zone) {
zone_(zone),
deferred_handles_(NULL) {
Initialize(BASE);
}
......@@ -97,11 +99,17 @@ CompilationInfo::CompilationInfo(Handle<JSFunction> closure, Zone* zone)
extension_(NULL),
pre_parse_data_(NULL),
osr_ast_id_(AstNode::kNoNumber),
zone_(zone) {
zone_(zone),
deferred_handles_(NULL) {
Initialize(BASE);
}
CompilationInfo::~CompilationInfo() {
delete deferred_handles_;
}
// Disable optimization for the rest of the compilation pipeline.
void CompilationInfo::DisableOptimization() {
bool is_optimizable_closure =
......
......@@ -45,6 +45,8 @@ class CompilationInfo BASE_EMBEDDED {
CompilationInfo(Handle<SharedFunctionInfo> shared_info, Zone* zone);
CompilationInfo(Handle<JSFunction> closure, Zone* zone);
~CompilationInfo();
Isolate* isolate() {
ASSERT(Isolate::Current() == isolate_);
return isolate_;
......@@ -173,6 +175,11 @@ class CompilationInfo BASE_EMBEDDED {
// current compilation pipeline.
void AbortOptimization();
void set_deferred_handles(DeferredHandles* deferred_handles) {
ASSERT(deferred_handles_ == NULL);
deferred_handles_ = deferred_handles;
}
private:
Isolate* isolate_;
......@@ -259,6 +266,8 @@ class CompilationInfo BASE_EMBEDDED {
// CompilationInfo allocates.
Zone* zone_;
DeferredHandles* deferred_handles_;
DISALLOW_COPY_AND_ASSIGN(CompilationInfo);
};
......@@ -286,6 +295,23 @@ class CompilationInfoWithZone: public CompilationInfo {
};
// A wrapper around a CompilationInfo that detaches the Handles from
// the underlying DeferredHandleScope and stores them in info_ on
// destruction.
class CompilationHandleScope BASE_EMBEDDED {
public:
explicit CompilationHandleScope(CompilationInfo* info)
: deferred_(info->isolate()), info_(info) {}
~CompilationHandleScope() {
info_->set_deferred_handles(deferred_.Detach());
}
private:
DeferredHandleScope deferred_;
CompilationInfo* info_;
};
// The V8 compiler
//
// General strategy: Source code is translated into an anonymous function w/o
......
......@@ -958,4 +958,45 @@ int Utf8Length(Handle<String> str) {
return len;
}
DeferredHandleScope::DeferredHandleScope(Isolate* isolate)
: impl_(isolate->handle_scope_implementer()) {
impl_->BeginDeferredScope();
Object** new_next = impl_->GetSpareOrNewBlock();
Object** new_limit = &new_next[kHandleBlockSize];
impl_->blocks()->Add(new_next);
v8::ImplementationUtilities::HandleScopeData* data =
impl_->isolate()->handle_scope_data();
#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--;
ASSERT(handles_detached_);
ASSERT(impl_->isolate()->handle_scope_data()->level == prev_level_);
}
DeferredHandles* DeferredHandleScope::Detach() {
DeferredHandles* deferred = impl_->Detach(prev_limit_);
v8::ImplementationUtilities::HandleScopeData* data =
impl_->isolate()->handle_scope_data();
data->next = prev_next_;
data->limit = prev_limit_;
#ifdef DEBUG
handles_detached_ = true;
#endif
return deferred;
}
} } // namespace v8::internal
......@@ -95,6 +95,9 @@ class Handle {
};
class HandleScopeImplementer;
// A stack-allocated class that governs a number of local handles.
// After a handle scope has been created, all local handles will be
// allocated within that handle scope until either the handle scope is
......@@ -157,10 +160,37 @@ class HandleScope {
static void ZapRange(internal::Object** start, internal::Object** end);
friend class v8::HandleScope;
friend class v8::internal::HandleScopeImplementer;
friend class v8::ImplementationUtilities;
};
class DeferredHandles;
class DeferredHandleScope {
public:
explicit DeferredHandleScope(Isolate* isolate);
// The DeferredHandles object returned stores the Handles created
// since the creation of this DeferredHandleScope. The Handles are
// alive as long as the DeferredHandles object is alive.
DeferredHandles* Detach();
~DeferredHandleScope();
private:
Object** prev_limit_;
Object** prev_next_;
HandleScopeImplementer* impl_;
#ifdef DEBUG
bool handles_detached_;
int prev_level_;
#endif
friend class HandleScopeImplementer;
};
// ----------------------------------------------------------------------------
// Handle operations.
// They might invoke garbage collection. The result is an handle to
......
......@@ -3053,6 +3053,7 @@ HGraph* HGraphBuilder::CreateGraph() {
{
HPhase phase("H_Block building");
CompilationHandleScope handle_scope(info());
current_block_ = graph()->entry_block();
Scope* scope = info()->scope();
......
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