Keep track of script objects in a weak fixed array.

src/debug/debug.cc

 // 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/debug/debug.h"
 
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 22 matching lines @@
       message_handler_(NULL),
       command_received_(0),
       command_queue_(isolate->logger(), kQueueInitialSize),
       is_active_(false),
       is_suppressed_(false),
       live_edit_enabled_(true),  // TODO(yangguo): set to false by default.
       break_disabled_(false),
       in_debug_event_listener_(false),
       break_on_exception_(false),
       break_on_uncaught_exception_(false),
-      script_cache_(NULL),
       debug_info_list_(NULL),
       isolate_(isolate) {
   ThreadInit();
 }
 
 
 static v8::Local<v8::Context> GetDebugEventContext(Isolate* isolate) {
   Handle<Context> context = isolate->debug()->debugger_entry()->GetContext();
   // Isolate::context() may have been NULL when "script collected" event
   // occured.
@@ skipping 293 matching lines @@
   MemCopy(reinterpret_cast<char*>(&thread_local_), from, sizeof(ThreadLocal));
   return storage + ArchiveSpacePerThread();
 }
 
 
 int Debug::ArchiveSpacePerThread() {
   return sizeof(ThreadLocal);
 }
 
 
-ScriptCache::ScriptCache(Isolate* isolate) : isolate_(isolate) {
-  Heap* heap = isolate_->heap();
-  HandleScope scope(isolate_);
-
-  DCHECK(isolate_->debug()->is_active());
-
-  // Perform a GC to get rid of all unreferenced scripts.
-  heap->CollectAllGarbage(Heap::kMakeHeapIterableMask, "ScriptCache");
-
-  // Scan heap for Script objects.
-  List<Handle<Script> > scripts;
-  {
-    HeapIterator iterator(heap, HeapIterator::kFilterUnreachable);
-    DisallowHeapAllocation no_allocation;
-    for (HeapObject* obj = iterator.next(); obj != NULL;
-         obj = iterator.next()) {
-      if (obj->IsScript() && Script::cast(obj)->HasValidSource()) {
-        scripts.Add(Handle<Script>(Script::cast(obj)));
-      }
-    }
-  }
-
-  GlobalHandles* global_handles = isolate_->global_handles();
-  table_ = Handle<WeakValueHashTable>::cast(global_handles->Create(
-      Object::cast(*WeakValueHashTable::New(isolate_, scripts.length()))));
-  for (int i = 0; i < scripts.length(); i++) Add(scripts[i]);
-}
-
-
-void ScriptCache::Add(Handle<Script> script) {
-  HandleScope scope(isolate_);
-  Handle<Smi> id(script->id(), isolate_);
-
-#ifdef DEBUG
-  Handle<Object> lookup(table_->LookupWeak(id), isolate_);
-  if (!lookup->IsTheHole()) {
-    Handle<Script> found = Handle<Script>::cast(lookup);
-    DCHECK(script->id() == found->id());
-    DCHECK(!script->name()->IsString() ||
-           String::cast(script->name())->Equals(String::cast(found->name())));
-  }
-#endif
-
-  Handle<WeakValueHashTable> new_table =
-      WeakValueHashTable::PutWeak(table_, id, script);
-
-  if (new_table.is_identical_to(table_)) return;
-  GlobalHandles* global_handles = isolate_->global_handles();
-  global_handles->Destroy(Handle<Object>::cast(table_).location());
-  table_ = Handle<WeakValueHashTable>::cast(
-      global_handles->Create(Object::cast(*new_table)));
-}
-
-
-ScriptCache::~ScriptCache() {
-  isolate_->global_handles()->Destroy(Handle<Object>::cast(table_).location());
-  table_ = Handle<WeakValueHashTable>();
-}
-
-
 DebugInfoListNode::DebugInfoListNode(DebugInfo* debug_info): next_(NULL) {
   // Globalize the request debug info object and make it weak.
   GlobalHandles* global_handles = debug_info->GetIsolate()->global_handles();
   debug_info_ =
       Handle<DebugInfo>::cast(global_handles->Create(debug_info)).location();
 }
 
 
 DebugInfoListNode::~DebugInfoListNode() {
   if (debug_info_ == nullptr) return;
@@ skipping 32 matching lines @@
 }
 
 
 void Debug::Unload() {
   ClearAllBreakPoints();
   ClearStepping();
 
   // Return debugger is not loaded.
   if (!is_loaded()) return;
 
-  // Clear the script cache.
-  if (script_cache_ != NULL) {
-    delete script_cache_;
-    script_cache_ = NULL;
-  }
-
   // Clear debugger context global handle.
   GlobalHandles::Destroy(Handle<Object>::cast(debug_context_).location());
   debug_context_ = Handle<Context>();
 }
 
 
 void Debug::Break(Arguments args, JavaScriptFrame* frame) {
   Heap* heap = isolate_->heap();
   HandleScope scope(isolate_);
   DCHECK(args.length() == 0);
@@ skipping 1183 matching lines @@
 
 
 void Debug::ClearMirrorCache() {
   PostponeInterruptsScope postpone(isolate_);
   HandleScope scope(isolate_);
   CallFunction("ClearMirrorCache", 0, NULL);
 }
 
 
 Handle<FixedArray> Debug::GetLoadedScripts() {
-  // Create and fill the script cache when the loaded scripts is requested for
-  // the first time.
-  if (script_cache_ == NULL) script_cache_ = new ScriptCache(isolate_);
-
-  // Perform GC to get unreferenced scripts evicted from the cache before
-  // returning the content.
   isolate_->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                       "Debug::GetLoadedScripts");
-
-  // Get the scripts from the cache.
-  return script_cache_->GetScripts();
+  Factory* factory = isolate_->factory();
+  if (!factory->script_list()->IsWeakFixedArray()) {
+    return factory->empty_fixed_array();
+  }
+  Handle<WeakFixedArray> array =
+      Handle<WeakFixedArray>::cast(factory->script_list());
+  Handle<FixedArray> results = factory->NewFixedArray(array->Length());
+  int length = 0;
+  for (int i = 0; i < array->Length(); ++i) {
+    Object* item = array->Get(i);
+    if (item->IsScript() && Script::cast(item)->HasValidSource()) {
+      results->set(length++, item);
+    }
+  }
+  results->Shrink(length);
+  return results;
 }
 
 
 void Debug::GetStepinPositions(JavaScriptFrame* frame, StackFrame::Id frame_id,
                                List<int>* results_out) {
   FrameSummary summary = GetFirstFrameSummary(frame);
 
   Handle<JSFunction> fun = Handle<JSFunction>(summary.function());
   Handle<SharedFunctionInfo> shared = Handle<SharedFunctionInfo>(fun->shared());
 
@@ skipping 231 matching lines @@
 
   // Process debug event.
   ProcessDebugEvent(v8::BeforeCompile,
                     Handle<JSObject>::cast(event_data),
                     true);
 }
 
 
 // Handle debugger actions when a new script is compiled.
 void Debug::OnAfterCompile(Handle<Script> script) {
-  // Add the newly compiled script to the script cache.
-  if (script_cache_ != NULL) script_cache_->Add(script);
-
   if (ignore_events()) return;
 
   if (in_debug_scope()) {
     ProcessCompileEventInDebugScope(v8::AfterCompile, script);
     return;
   }
 
   HandleScope scope(isolate_);
   DebugScope debug_scope(this);
   if (debug_scope.failed()) return;
@@ skipping 723 matching lines @@
 }
 
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 }  // namespace internal
 }  // namespace v8