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 105 matching lines @@
   ~Scavenger();
 
   // Check whether this Scavenger contains this address.
   // 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) {
+  uword TryAllocate(intptr_t size) { return TryAllocateGC(size); }
+
+  uword TryAllocateGC(intptr_t size) {
     ASSERT(Utils::IsAligned(size, kObjectAlignment));
     ASSERT(heap_ != Dart::vm_isolate()->heap());
+
 #if defined(DEBUG)
     if (FLAG_gc_at_alloc && !scavenging_) {
       Scavenge();
     }
 #endif
+
     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()));
+
     return result;
   }
 
+  uword TryAllocateInTLAB(Thread* thread, intptr_t size) {
+    ASSERT(Utils::IsAligned(size, kObjectAlignment));
+    ASSERT(heap_ != Dart::vm_isolate()->heap());
+
+    ASSERT(thread->IsMutatorThread());
+    ASSERT(thread->heap() == heap_);
+
+#if defined(DEBUG)
+    if (FLAG_gc_at_alloc && !scavenging_) {
+      Scavenge();
+    }
+#endif
+
+    uword top = thread->top();
+    uword end = thread->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()));
+
+    thread->set_top(top);
+    return result;
+  }
+
   // Collect the garbage in this scavenger.
   void Scavenge();
   void Scavenge(bool invoke_api_callbacks);
 
   // Promote all live objects.
-  void Evacuate();
+  void Evacuate(Thread* thread);
 
   // Accessors to generate code for inlined allocation.

[rmacnak, 2017/07/12 17:10:22]

Remove TopAddress and EndAddress.

[danunez, 2017/07/12 18:23:38]

Done.

   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_); }
+
+  uword top() { return top_; }
+  uword end() { return end_; }
+
+  void set_top(uword value) { top_ = value; }
+  void set_end(uword value) {
+    ASSERT(to_->end() == value);
+    end_ = value;
+  }
 
   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; }
   SpaceUsage GetCurrentUsage() const {
     SpaceUsage usage;
     usage.used_in_words = UsedInWords();
     usage.capacity_in_words = CapacityInWords();
@@ skipping 16 matching lines @@
 
   intptr_t collections() const { return collections_; }
 
 #ifndef PRODUCT
   void PrintToJSONObject(JSONObject* object) const;
 #endif  // !PRODUCT
 
   void AllocateExternal(intptr_t size);
   void FreeExternal(intptr_t size);
 
+  void FlushTLS() const;
+
  private:
   // Ids for time and data records in Heap::GCStats.
   enum {
     // Time
     kDummyScavengeTime = 0,
     kSafePoint = 1,
     kVisitIsolateRoots = 2,
     kIterateStoreBuffers = 3,
     kProcessToSpace = 4,
     kIterateWeaks = 5,
@@ skipping 19 matching lines @@
   void Epilogue(Isolate* isolate, SemiSpace* from, bool invoke_api_callbacks);
 
   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_);
+

[rmacnak, 2017/07/12 17:10:22]

Remove spurious whitespace changes. 

[danunez, 2017/07/12 18:23:38]

Done.

     end_ -= sizeof(addr);
+
     ASSERT(end_ > top_);
     *reinterpret_cast<uword*>(end_) = addr;
   }
   uword PopFromPromotedStack() {
     ASSERT(scavenging_);
+
     uword result = *reinterpret_cast<uword*>(end_);
     end_ += sizeof(result);
+
     ASSERT(end_ <= to_->end());
     return result;
   }
   bool PromotedStackHasMore() const {
     ASSERT(scavenging_);
     return end_ < to_->end();
   }
 
   void UpdateMaxHeapCapacity();
   void UpdateMaxHeapUsage();
 
   void ProcessWeakReferences();
 
   intptr_t NewSizeInWords(intptr_t old_size_in_words) const;
 
   // Accessed from generated code.

[rmacnak, 2017/07/12 17:10:22]

Remove comment. No longer accessed from generated code.

And comment about the true value residing on the mutator Thread object during
regular program execution, and residing here during a GC/iteration.

[danunez, 2017/07/12 18:23:38]

Done.

   // ** This block of fields must come first! **
   // For AOT cross-compilation, we rely on these members having the same offsets
   // in SIMARM(IA32) and ARM, and the same offsets in SIMARM64(X64) and ARM64.
   // We use only word-sized fields to avoid differences in struct packing on the
   // different architectures. See also CheckOffsets in dart.cc.
   uword top_;
   uword end_;
 
   SemiSpace* to_;
 
@@ skipping 19 matching lines @@
 
   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_;
 
   bool failed_to_promote_;
+  Mutex* space_lock_;
 
   friend class ScavengerVisitor;
   friend class ScavengerWeakVisitor;
 
   DISALLOW_COPY_AND_ASSIGN(Scavenger);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_SCAVENGER_H_