Update the Idle collector to do a full GC

after being idle for some time.

Remove the default argument from CollectAllGarbage.

Review URL: http://codereview.chromium.org/174302

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2748 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -2280,9 +2280,13 @@ class V8EXPORT V8 {
   /**
    * Optional notification that the embedder is idle.
    * V8 uses the notification to reduce memory footprint.
+   * This call can be used repeatedly if the embedder remains idle.
    * \param is_high_priority tells whether the embedder is high priority.
+   * Returns true if the embedder should stop calling IdleNotification
+   * until real work has been done.  This indicates that V8 has done
+   * as much cleanup as it will be able to do.
    */
-  static void IdleNotification(bool is_high_priority);
+  static bool IdleNotification(bool is_high_priority);
 
   /**
    * Optional notification that the system is running low on memory.

src/api.cc

@@ -2604,8 +2604,8 @@ bool v8::V8::Dispose() {
 }
 
 
-void v8::V8::IdleNotification(bool is_high_priority) {
-  i::V8::IdleNotification(is_high_priority);
+bool v8::V8::IdleNotification(bool is_high_priority) {
+  return i::V8::IdleNotification(is_high_priority);
 }
 
 
@@ -3335,7 +3335,7 @@ void V8::ResumeProfilerEx(int flags) {
     flags &= ~(PROFILER_MODULE_HEAP_SNAPSHOT | PROFILER_MODULE_CPU);
     const int current_flags = i::Logger::GetActiveProfilerModules();
     i::Logger::ResumeProfiler(flags);
-    i::Heap::CollectAllGarbage();
+    i::Heap::CollectAllGarbage(false);
     i::Logger::PauseProfiler(~current_flags & flags);
   } else {
     i::Logger::ResumeProfiler(flags);

src/debug.cc

@@ -1548,8 +1548,8 @@ void Debug::CreateScriptCache() {
   // Perform two GCs to get rid of all unreferenced scripts. The first GC gets
   // rid of all the cached script wrappers and the second gets rid of the
   // scripts which is no longer referenced.
-  Heap::CollectAllGarbage();
-  Heap::CollectAllGarbage();
+  Heap::CollectAllGarbage(false);
+  Heap::CollectAllGarbage(false);
 
   ASSERT(script_cache_ == NULL);
   script_cache_ = new ScriptCache();
@@ -1599,7 +1599,7 @@ Handle<FixedArray> Debug::GetLoadedScripts() {
 
   // Perform GC to get unreferenced scripts evicted from the cache before
   // returning the content.
-  Heap::CollectAllGarbage();
+  Heap::CollectAllGarbage(false);
 
   // Get the scripts from the cache.
   return script_cache_->GetScripts();

src/execution.cc

@@ -677,7 +677,7 @@ v8::Handle<v8::FunctionTemplate> GCExtension::GetNativeFunction(
 
 v8::Handle<v8::Value> GCExtension::GC(const v8::Arguments& args) {
   // All allocation spaces other than NEW_SPACE have the same effect.
-  Heap::CollectAllGarbage();
+  Heap::CollectAllGarbage(false);
   return v8::Undefined();
 }
 

src/heap-inl.h

@@ -238,7 +238,7 @@ int Heap::AdjustAmountOfExternalAllocatedMemory(int change_in_bytes) {
         amount_of_external_allocated_memory_ -
         amount_of_external_allocated_memory_at_last_global_gc_;
     if (amount_since_last_global_gc > external_allocation_limit_) {
-      CollectAllGarbage();
+      CollectAllGarbage(false);
     }
   } else {
     // Avoid underflow.
@@ -285,7 +285,7 @@ void Heap::SetLastScriptId(Object* last_script_id) {
     }                                                                     \
     if (!__object__->IsRetryAfterGC()) RETURN_EMPTY;                      \
     Counters::gc_last_resort_from_handles.Increment();                    \
-    Heap::CollectAllGarbage();                                            \
+    Heap::CollectAllGarbage(false);                                       \
     {                                                                     \
       AlwaysAllocateScope __scope__;                                      \
       __object__ = FUNCTION_CALL;                                         \

src/heap.cc

@@ -332,7 +332,7 @@ void Heap::CollectAllGarbageIfContextDisposed() {
   // informed decisions about when to force a collection.
   if (!FLAG_expose_gc && context_disposed_pending_) {
     HistogramTimerScope scope(&Counters::gc_context);
-    CollectAllGarbage();
+    CollectAllGarbage(false);
   }
   context_disposed_pending_ = false;
 }

src/heap.h

@@ -629,7 +629,7 @@ class Heap : public AllStatic {
 
   // Performs a full garbage collection. Force compaction if the
   // parameter is true.
-  static void CollectAllGarbage(bool force_compaction = false);
+  static void CollectAllGarbage(bool force_compaction);
 
   // Performs a full garbage collection if a context has been disposed
   // since the last time the check was performed.
@@ -842,6 +842,39 @@ class Heap : public AllStatic {
            > old_gen_allocation_limit_;
   }
 
+  // Can be called when the embedding application is idle.
+  static bool IdleNotification() {
+    static const int kIdlesBeforeCollection = 7;
+    static int number_idle_notifications = 0;
+    static int last_gc_count = gc_count_;
+
+    bool finished = false;
+
+    if (last_gc_count == gc_count_) {
+      number_idle_notifications++;
+    } else {
+      number_idle_notifications = 0;
+      last_gc_count = gc_count_;
+    }
+
+    if (number_idle_notifications >= kIdlesBeforeCollection) {
+      // The first time through we collect without forcing compaction.
+      // The second time through we force compaction and quit.
+      bool force_compaction =
+          number_idle_notifications > kIdlesBeforeCollection;
+      CollectAllGarbage(force_compaction);
+      last_gc_count = gc_count_;
+      if (force_compaction) {
+        number_idle_notifications = 0;
+        finished = true;
+      }
+    }
+
+    // Uncommit unused memory in new space.
+    Heap::UncommitFromSpace();
+    return finished;
+  }
+
   // Declare all the root indices.
   enum RootListIndex {
 #define ROOT_INDEX_DECLARATION(type, name, camel_name) k##camel_name##RootIndex,

src/mksnapshot.cc

@@ -171,7 +171,7 @@ int main(int argc, char** argv) {
     }
   }
   // Get rid of unreferenced scripts with a global GC.
-  i::Heap::CollectAllGarbage();
+  i::Heap::CollectAllGarbage(false);
   i::Serializer ser;
   ser.Serialize();
   v8::internal::byte* bytes;

src/runtime.cc

@@ -7263,7 +7263,7 @@ static Object* Runtime_DebugReferencedBy(Arguments args) {
   ASSERT(args.length() == 3);
 
   // First perform a full GC in order to avoid references from dead objects.
-  Heap::CollectAllGarbage();
+  Heap::CollectAllGarbage(false);
 
   // Check parameters.
   CONVERT_CHECKED(JSObject, target, args[0]);
@@ -7339,7 +7339,7 @@ static Object* Runtime_DebugConstructedBy(Arguments args) {
   ASSERT(args.length() == 2);
 
   // First perform a full GC in order to avoid dead objects.
-  Heap::CollectAllGarbage();
+  Heap::CollectAllGarbage(false);
 
   // Check parameters.
   CONVERT_CHECKED(JSFunction, constructor, args[0]);
@@ -7633,7 +7633,7 @@ void Runtime::PerformGC(Object* result) {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
-    Heap::CollectAllGarbage();
+    Heap::CollectAllGarbage(false);
   }
 }
 

src/v8.cc

@@ -157,13 +157,13 @@ uint32_t V8::Random() {
 }
 
 
-void V8::IdleNotification(bool is_high_priority) {
-  if (!FLAG_use_idle_notification) return;
+bool V8::IdleNotification(bool is_high_priority) {
+  if (!FLAG_use_idle_notification) return false;
   // Ignore high priority instances of V8.
-  if (is_high_priority) return;
+  if (is_high_priority) return false;
 
-  // Uncommit unused memory in new space.
-  Heap::UncommitFromSpace();
+  // Tell the heap that it may want to adjust.
+  return Heap::IdleNotification();
 }
 
 

src/v8.h

@@ -100,7 +100,7 @@ class V8 : public AllStatic {
   static Smi* RandomPositiveSmi();
 
   // Idle notification directly from the API.
-  static void IdleNotification(bool is_high_priority);
+  static bool IdleNotification(bool is_high_priority);
 
  private:
   // True if engine is currently running