Attempt to collect more garbage before panicking with out of memory.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 443c926d95b9eff79e26e56a0294564174b5473c..3c3716acfdc2faa7063806166dfe2bd5f8d54ad9 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -55,7 +55,6 @@ namespace internal {
 String* Heap::hidden_symbol_;
 Object* Heap::roots_[Heap::kRootListLength];
 
-
 NewSpace Heap::new_space_;
 OldSpace* Heap::old_pointer_space_ = NULL;
 OldSpace* Heap::old_data_space_ = NULL;
@@ -64,9 +63,6 @@ MapSpace* Heap::map_space_ = NULL;
 CellSpace* Heap::cell_space_ = NULL;
 LargeObjectSpace* Heap::lo_space_ = NULL;
 
-static const int kMinimumPromotionLimit = 2*MB;
-static const int kMinimumAllocationLimit = 8*MB;
-
 int Heap::old_gen_promotion_limit_ = kMinimumPromotionLimit;
 int Heap::old_gen_allocation_limit_ = kMinimumAllocationLimit;
 
@@ -405,17 +401,26 @@ void Heap::GarbageCollectionEpilogue() {
 }
 
 
-void Heap::CollectAllGarbage(bool force_compaction) {
+void Heap::CollectAllGarbage(bool force_compaction,
+                             CollectionPolicy collectionPolicy) {
   // Since we are ignoring the return value, the exact choice of space does
   // not matter, so long as we do not specify NEW_SPACE, which would not
   // cause a full GC.
   MarkCompactCollector::SetForceCompaction(force_compaction);
-  CollectGarbage(0, OLD_POINTER_SPACE);
+  CollectGarbage(0, OLD_POINTER_SPACE, collectionPolicy);
   MarkCompactCollector::SetForceCompaction(false);
 }
 
 
-bool Heap::CollectGarbage(int requested_size, AllocationSpace space) {
+void Heap::CollectAllAvailableGarbage() {
+  CompilationCache::Clear();
+  CollectAllGarbage(true, AGGRESSIVE);
+}
+
+
+bool Heap::CollectGarbage(int requested_size,
+                          AllocationSpace space,
+                          CollectionPolicy collectionPolicy) {
   // The VM is in the GC state until exiting this function.
   VMState state(GC);
 
@@ -442,7 +447,7 @@ bool Heap::CollectGarbage(int requested_size, AllocationSpace space) {
         ? &Counters::gc_scavenger
         : &Counters::gc_compactor;
     rate->Start();
-    PerformGarbageCollection(space, collector, &tracer);
+    PerformGarbageCollection(collector, &tracer, collectionPolicy);
     rate->Stop();
 
     GarbageCollectionEpilogue();
@@ -475,7 +480,7 @@ bool Heap::CollectGarbage(int requested_size, AllocationSpace space) {
 
 void Heap::PerformScavenge() {
   GCTracer tracer;
-  PerformGarbageCollection(NEW_SPACE, SCAVENGER, &tracer);
+  PerformGarbageCollection(SCAVENGER, &tracer, NORMAL);
 }
 
 
@@ -664,9 +669,9 @@ void Heap::UpdateSurvivalRateTrend(int start_new_space_size) {
   survival_rate_ = survival_rate;
 }
 
-void Heap::PerformGarbageCollection(AllocationSpace space,
-                                    GarbageCollector collector,
-                                    GCTracer* tracer) {
+void Heap::PerformGarbageCollection(GarbageCollector collector,
+                                    GCTracer* tracer,
+                                    CollectionPolicy collectionPolicy) {
   VerifySymbolTable();
   if (collector == MARK_COMPACTOR && global_gc_prologue_callback_) {
     ASSERT(!allocation_allowed_);
@@ -696,25 +701,44 @@ void Heap::PerformGarbageCollection(AllocationSpace space,
 
     UpdateSurvivalRateTrend(start_new_space_size);
 
-    int old_gen_size = PromotedSpaceSize();
-    old_gen_promotion_limit_ =
-        old_gen_size + Max(kMinimumPromotionLimit, old_gen_size / 3);
-    old_gen_allocation_limit_ =
-        old_gen_size + Max(kMinimumAllocationLimit, old_gen_size / 2);
-
-    if (high_survival_rate_during_scavenges &&
-        IsStableOrIncreasingSurvivalTrend()) {
-      // Stable high survival rates of young objects both during partial and
-      // full collection indicate that mutator is either building or modifying
-      // a structure with a long lifetime.
-      // In this case we aggressively raise old generation memory limits to
-      // postpone subsequent mark-sweep collection and thus trade memory
-      // space for the mutation speed.
-      old_gen_promotion_limit_ *= 2;
-      old_gen_allocation_limit_ *= 2;
+    UpdateOldSpaceLimits();
+
+    // Major GC would invoke weak handle callbacks on weakly reachable
+    // handles, but won't collect weakly reachable objects until next
+    // major GC.  Therefore if we collect aggressively and weak handle callback
+    // has been invoked, we rerun major GC to release objects which become
+    // garbage.
+    if (collectionPolicy == AGGRESSIVE) {
+      // Note: as weak callbacks can execute arbitrary code, we cannot
+      // hope that eventually there will be no weak callbacks invocations.
+      // Therefore stop recollecting after several attempts.
+      const int kMaxNumberOfAttempts = 7;
+      for (int attempt = 0; attempt < kMaxNumberOfAttempts; attempt++) {
+        { DisableAssertNoAllocation allow_allocation;
+          GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL);
+          if (!GlobalHandles::PostGarbageCollectionProcessing()) break;
+        }
+        MarkCompact(tracer);
+        // Weak handle callbacks can allocate data, so keep limits correct.
+        UpdateOldSpaceLimits();
+      }
+    } else {
+      if (high_survival_rate_during_scavenges &&
+          IsStableOrIncreasingSurvivalTrend()) {
+        // Stable high survival rates of young objects both during partial and
+        // full collection indicate that mutator is either building or modifying
+        // a structure with a long lifetime.
+        // In this case we aggressively raise old generation memory limits to
+        // postpone subsequent mark-sweep collection and thus trade memory
+        // space for the mutation speed.
+        old_gen_promotion_limit_ *= 2;
+        old_gen_allocation_limit_ *= 2;
+      }
+    }
+    { DisableAssertNoAllocation allow_allocation;

[Vyacheslav Egorov (Chromium), 2010/09/14 17:08:42]

Empty line before this one might help readability. 

+      GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL);
+      GlobalHandles::PostGarbageCollectionProcessing();
     }
-
-    old_gen_exhausted_ = false;
   } else {
     tracer_ = tracer;
     Scavenge();
@@ -725,12 +749,6 @@ void Heap::PerformGarbageCollection(AllocationSpace space,
 
   Counters::objs_since_last_young.Set(0);
 
-  if (collector == MARK_COMPACTOR) {
-    DisableAssertNoAllocation allow_allocation;
-    GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL);
-    GlobalHandles::PostGarbageCollectionProcessing();
-  }
-
   // Update relocatables.
   Relocatable::PostGarbageCollectionProcessing();