Moves the top_ and end_ words of the Scavenger into mutator thread.

runtime/vm/scavenger.h

 // Copyright (c) 2012, 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.
 
 #ifndef RUNTIME_VM_SCAVENGER_H_
 #define RUNTIME_VM_SCAVENGER_H_
 
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/dart.h"
@@ skipping 106 matching lines @@
   // During scavenging both the to and from spaces contain "legal" objects.
   // During a scavenge this function only returns true for addresses that will
   // be part of the surviving objects.
   bool Contains(uword addr) const { return to_->Contains(addr); }
 
   RawObject* FindObject(FindObjectVisitor* visitor) const;
 
   uword TryAllocate(intptr_t size) {
     ASSERT(Utils::IsAligned(size, kObjectAlignment));
     ASSERT(heap_ != Dart::vm_isolate()->heap());
+
 #if defined(DEBUG)
     if (FLAG_gc_at_alloc && !scavenging_) {
       Scavenge();
+      ASSERT(Isolate::Current()->mutator_thread()->top() == top_);

[rmacnak, 2017/06/22 22:31:51]

Thread::Current() should be the mutator

[danunez, 2017/06/30 20:35:57]

Done.

     }
 #endif
+
+    top_ = Isolate::Current()->mutator_thread()->top();
+    ASSERT(Isolate::Current()->mutator_thread()->end() == end_);
+
     uword result = top_;
     intptr_t remaining = end_ - top_;
     if (remaining < size) {
       return 0;
     }
     ASSERT(to_->Contains(result));
     ASSERT((result & kObjectAlignmentMask) == object_alignment_);
 
     top_ += size;
     ASSERT(to_->Contains(top_) || (top_ == to_->end()));
+    Isolate::Current()->mutator_thread()->set_top_offset(top_);
     return result;
   }
 
   // Collect the garbage in this scavenger.
   void Scavenge();
   void Scavenge(bool invoke_api_callbacks);
 
   // Promote all live objects.
   void Evacuate() {
     Scavenge();
     Scavenge();
     ASSERT(UsedInWords() == 0);
   }
 
   // Accessors to generate code for inlined allocation.

[rmacnak, 2017/06/22 22:31:50]

Remove to check these are all unused now.

[danunez, 2017/06/30 20:35:57]

TopAddress() and EndAddress() are used, but only to initialize the mutator's
top_ and end_.

   uword* TopAddress() { return &top_; }
   uword* EndAddress() { return &end_; }
   static intptr_t top_offset() { return OFFSET_OF(Scavenger, top_); }
   static intptr_t end_offset() { return OFFSET_OF(Scavenger, end_); }
 
   int64_t UsedInWords() const {
     return (top_ - FirstObjectStart()) >> kWordSizeLog2;
   }
   int64_t CapacityInWords() const { return to_->size_in_words(); }
   int64_t ExternalInWords() const { return external_size_ >> kWordSizeLog2; }
@@ skipping 60 matching lines @@
 
   bool IsUnreachable(RawObject** p);
 
   // During a scavenge we need to remember the promoted objects.
   // This is implemented as a stack of objects at the end of the to space. As
   // object sizes are always greater than sizeof(uword) and promoted objects do
   // not consume space in the to space they leave enough room for this stack.
   void PushToPromotedStack(uword addr) {
     ASSERT(scavenging_);
     end_ -= sizeof(addr);
+    Isolate::Current()->mutator_thread()->set_end_offset(end_);
     ASSERT(end_ > top_);
     *reinterpret_cast<uword*>(end_) = addr;
   }
   uword PopFromPromotedStack() {
     ASSERT(scavenging_);
     uword result = *reinterpret_cast<uword*>(end_);
     end_ += sizeof(result);
+    Isolate::Current()->mutator_thread()->set_end_offset(end_);
     ASSERT(end_ <= to_->end());
     return result;
   }
   bool PromotedStackHasMore() const {
     ASSERT(scavenging_);
     return end_ < to_->end();
   }
 
   void UpdateMaxHeapCapacity();
   void UpdateMaxHeapUsage();
@@ skipping 34 matching lines @@
   RawWeakProperty* delayed_weak_properties_;
 
   int64_t gc_time_micros_;
   intptr_t collections_;
   static const int kStatsHistoryCapacity = 2;
   RingBuffer<ScavengeStats, kStatsHistoryCapacity> stats_history_;
 
   // The total size of external data associated with objects in this scavenger.
   intptr_t external_size_;
 
+  Mutex* space_lock_;
+
   friend class ScavengerVisitor;
   friend class ScavengerWeakVisitor;
 
   DISALLOW_COPY_AND_ASSIGN(Scavenger);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_SCAVENGER_H_