Revision: 3984
Author: [email protected]
Date: Mon Mar 1 00:49:33 2010
Log: Tweak the new context disposal GC heuristic to cleanly separate
it from the old heuristic (disabled if the new notications are
used) and make sure to not force a GC if one has already happened
after V8 received the last context disposal notification.
Review URL: http://codereview.chromium.org/660267
http://code.google.com/p/v8/source/detail?r=3984
Modified:
/branches/bleeding_edge/include/v8.h
/branches/bleeding_edge/src/api.cc
/branches/bleeding_edge/src/heap.cc
/branches/bleeding_edge/src/heap.h
=======================================
--- /branches/bleeding_edge/include/v8.h Fri Feb 26 03:51:33 2010
+++ /branches/bleeding_edge/include/v8.h Mon Mar 1 00:49:33 2010
@@ -2474,9 +2474,8 @@
static void LowMemoryNotification();
/**
- * Optional notification that one or more context have been
- * disposed. V8 may choose to collect garbage to get rid of any
- * external memory associated with the disposed contexts.
+ * Optional notification that a context has been disposed. V8 uses
+ * these notifications to guide the garbage collection heuristic.
*/
static void ContextDisposedNotification();
=======================================
--- /branches/bleeding_edge/src/api.cc Fri Feb 26 06:37:33 2010
+++ /branches/bleeding_edge/src/api.cc Mon Mar 1 00:49:33 2010
@@ -438,7 +438,7 @@
void V8::DisposeGlobal(i::Object** obj) {
LOG_API("DisposeGlobal");
if (!i::V8::IsRunning()) return;
- if ((*obj)->IsGlobalContext()) i::Heap::NotifyContextDisposed();
+ if ((*obj)->IsGlobalContext())
i::Heap::NotifyContextDisposedDeprecated();
i::GlobalHandles::Destroy(obj);
}
@@ -2823,7 +2823,7 @@
void v8::V8::ContextDisposedNotification() {
if (!i::V8::IsRunning()) return;
- i::Heap::CollectAllGarbageIfContextDisposed(true);
+ i::Heap::NotifyContextDisposed();
}
@@ -2863,7 +2863,7 @@
// decide when should make a full GC.
#else
// Give the heap a chance to cleanup if we've disposed contexts.
- i::Heap::CollectAllGarbageIfContextDisposed(false);
+ i::Heap::CollectAllGarbageIfContextDisposedDeprecated();
#endif
v8::Handle<ObjectTemplate> proxy_template = global_template;
i::Handle<i::FunctionTemplateInfo> proxy_constructor;
=======================================
--- /branches/bleeding_edge/src/heap.cc Sun Feb 28 23:04:42 2010
+++ /branches/bleeding_edge/src/heap.cc Mon Mar 1 00:49:33 2010
@@ -115,7 +115,10 @@
int Heap::always_allocate_scope_depth_ = 0;
int Heap::linear_allocation_scope_depth_ = 0;
-bool Heap::context_disposed_pending_ = false;
+
+int Heap::contexts_disposed_ = 0;
+bool Heap::context_disposed_use_deprecated_heuristic_ = true;
+bool Heap::context_disposed_deprecated_pending_ = false;
#ifdef DEBUG
bool Heap::allocation_allowed_ = true;
@@ -371,29 +374,29 @@
}
-void Heap::CollectAllGarbageIfContextDisposed(bool notified) {
- // If the request has ever been the result of an explicit
- // notification, we ignore non-notified requests. This is a
- // temporary solution to let the two ways of achieving GC at
- // context disposal time co-exist.
- static bool ever_notified = false;
- if (notified) ever_notified = true;
- if (ever_notified && !notified) return;
-
+void Heap::CollectAllGarbageIfContextDisposedDeprecated() {
+ if (!context_disposed_use_deprecated_heuristic_) return;
// If the garbage collector interface is exposed through the global
// gc() function, we avoid being clever about forcing GCs when
// contexts are disposed and leave it to the embedder to make
// informed decisions about when to force a collection.
- if (!FLAG_expose_gc && (notified || context_disposed_pending_)) {
+ if (!FLAG_expose_gc && context_disposed_deprecated_pending_) {
HistogramTimerScope scope(&Counters::gc_context);
CollectAllGarbage(false);
}
- context_disposed_pending_ = false;
+ context_disposed_deprecated_pending_ = false;
}
void Heap::NotifyContextDisposed() {
- context_disposed_pending_ = true;
+ context_disposed_use_deprecated_heuristic_ = false;
+ contexts_disposed_++;
+}
+
+
+void Heap::NotifyContextDisposedDeprecated() {
+ if (!context_disposed_use_deprecated_heuristic_) return;
+ context_disposed_deprecated_pending_ = true;
}
@@ -639,7 +642,9 @@
Shrink();
Counters::objs_since_last_full.Set(0);
- context_disposed_pending_ = false;
+
+ contexts_disposed_ = 0;
+ context_disposed_deprecated_pending_ = false;
}
@@ -3088,6 +3093,13 @@
static int number_idle_notifications = 0;
static int last_gc_count = gc_count_;
+ if (!FLAG_expose_gc && (contexts_disposed_ > 0)) {
+ HistogramTimerScope scope(&Counters::gc_context);
+ CollectAllGarbage(false);
+ ASSERT(contexts_disposed_ == 0);
+ return false;
+ }
+
bool finished = false;
if (last_gc_count == gc_count_) {
=======================================
--- /branches/bleeding_edge/src/heap.h Fri Feb 26 06:37:33 2010
+++ /branches/bleeding_edge/src/heap.h Mon Mar 1 00:49:33 2010
@@ -635,10 +635,11 @@
// Performs a full garbage collection if a context has been disposed
// since the last time the check was performed.
- static void CollectAllGarbageIfContextDisposed(bool notified);
+ static void CollectAllGarbageIfContextDisposedDeprecated();
// Notify the heap that a context has been disposed.
static void NotifyContextDisposed();
+ static void NotifyContextDisposedDeprecated();
// Utility to invoke the scavenger. This is needed in test code to
// ensure correct callback for weak global handles.
@@ -909,7 +910,11 @@
static int always_allocate_scope_depth_;
static int linear_allocation_scope_depth_;
- static bool context_disposed_pending_;
+
+ // For keeping track of context disposals.
+ static int contexts_disposed_;
+ static bool context_disposed_use_deprecated_heuristic_;
+ static bool context_disposed_deprecated_pending_;
#if defined(V8_TARGET_ARCH_X64)
static const int kMaxObjectSizeInNewSpace = 512*KB;
--
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