Track external allocated memory for weak persistent handles.

runtime/vm/scavenger.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/scavenger.h"
 
 #include <algorithm>
 #include <map>
 #include <utility>
 
@@ skipping 253 matching lines @@
   intptr_t bytes_promoted_;
   RawObject* visiting_old_object_;
   bool in_scavenge_pointer_;
 
   DISALLOW_COPY_AND_ASSIGN(ScavengerVisitor);
 };
 
 
 class ScavengerWeakVisitor : public HandleVisitor {
  public:
-  explicit ScavengerWeakVisitor(Scavenger* scavenger) : scavenger_(scavenger) {
-  }
+  explicit ScavengerWeakVisitor(Scavenger* scavenger)
+      : scavenger_(scavenger), heap_(scavenger->heap_) {}
 
   void VisitHandle(uword addr) {
     FinalizablePersistentHandle* handle =
-        reinterpret_cast<FinalizablePersistentHandle*>(addr);
+      reinterpret_cast<FinalizablePersistentHandle*>(addr);
     RawObject** p = handle->raw_addr();
+    RawObject* before = *p;
     if (scavenger_->IsUnreachable(p)) {
-      FinalizablePersistentHandle::Finalize(handle);
+      handle->UpdateUnreachable(heap_);
+    } else {
+      handle->UpdateRelocated(before, heap_);
     }
   }
 
  private:
   Scavenger* scavenger_;
+  Heap* heap_;
 
   DISALLOW_COPY_AND_ASSIGN(ScavengerWeakVisitor);
 };
 
 
 // Visitor used to verify that all old->new references have been added to the
 // StoreBuffers.
 class VerifyStoreBufferPointerVisitor : public ObjectPointerVisitor {
  public:
   VerifyStoreBufferPointerVisitor(Isolate* isolate, MemoryRegion* to)
@@ skipping 15 matching lines @@
 };
 
 
 Scavenger::Scavenger(Heap* heap,
                      intptr_t max_capacity_in_words,
                      uword object_alignment)
     : heap_(heap),
       object_alignment_(object_alignment),
       scavenging_(false),
       gc_time_micros_(0),
-      collections_(0) {
+      collections_(0),
+      external_allocation_size_(0) {
   // Verify assumptions about the first word in objects which the scavenger is
   // going to use for forwarding pointers.
   ASSERT(Object::tags_offset() == 0);
 
   // Allocate the virtual memory for this scavenge heap.
   space_ = VirtualMemory::Reserve(max_capacity_in_words << kWordSizeLog2);
   if (space_ == NULL) {
     FATAL("Out of memory.\n");
   }
 
@@ skipping 341 matching lines @@
   had_promotion_failure_ = false;
   Isolate* isolate = Isolate::Current();
   NoHandleScope no_handles(isolate);
 
   if (FLAG_verify_before_gc) {
     OS::PrintErr("Verifying before Scavenge...");
     heap_->Verify();
     OS::PrintErr(" done.\n");
   }
 
+  // During from/to flip and promoted stack use, move external allocation
+  // out of tospace temporarily.
+  intptr_t saved_external = external_allocation_size_;
+  FreeExternal(saved_external);
+
   // Setup the visitor and run a scavenge.
   ScavengerVisitor visitor(isolate, this);
   Prologue(isolate, invoke_api_callbacks);
   IterateRoots(isolate, &visitor, !invoke_api_callbacks);
   int64_t start = OS::GetCurrentTimeMicros();
   ProcessToSpace(&visitor);
   int64_t middle = OS::GetCurrentTimeMicros();
   IterateWeakReferences(isolate, &visitor);
+  // Done with promoted stack; restore external allocation.
+  ASSERT(!PromotedStackHasMore());
+  AllocateExternal(saved_external);
   ScavengerWeakVisitor weak_visitor(this);
   IterateWeakRoots(isolate, &weak_visitor, invoke_api_callbacks);
   visitor.Finalize();
   ProcessWeakTables();
   int64_t end = OS::GetCurrentTimeMicros();
   heap_->RecordTime(kProcessToSpace, middle - start);
   heap_->RecordTime(kIterateWeaks, end - middle);
   Epilogue(isolate, &visitor, invoke_api_callbacks);
 
   if (FLAG_verify_after_gc) {
@@ skipping 20 matching lines @@
   space.AddProperty("id", "heaps/new");
   space.AddProperty("name", "Scavenger");
   space.AddProperty("user_name", "new");
   space.AddProperty("collections", collections());
   space.AddProperty("used", UsedInWords() * kWordSize);
   space.AddProperty("capacity", CapacityInWords() * kWordSize);
   space.AddProperty("time", RoundMicrosecondsToSeconds(gc_time_micros()));
 }
 
 
+void Scavenger::AllocateExternal(intptr_t size) {
+  ASSERT(size >= 0);
+  external_allocation_size_ += size;
+  intptr_t remaining = end_ - top_;
+  end_ -= Utils::Minimum(remaining, size);
+}
+
+
+void Scavenger::FreeExternal(intptr_t size) {
+  ASSERT(size >= 0);
+  external_allocation_size_ -= size;
+  ASSERT(external_allocation_size_ >= 0);
+  end_ = Utils::Minimum(to_->end(), end_ + size);
+}
+
 }  // namespace dart