--verify-predictable mode added for ensuring that GC behaves deterministically.

src/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_H_
 #define V8_HEAP_H_
 
 #include <cmath>
 
 #include "src/allocation.h"
@@ skipping 958 matching lines @@
     return true;
 #else
 #ifdef VERIFY_HEAP
     return FLAG_verify_heap;
 #else
     return false;
 #endif
 #endif
   }
 
+  // Number of "runtime allocations" done so far.
+  uint32_t allocations_count() { return allocations_count_; }
+
+  // Returns deterministic "time" value in ms. Works only with
+  // FLAG_verify_predictable.
+  double synthetic_time() { return allocations_count_ / 100.0; }
+
   // Print short heap statistics.
   void PrintShortHeapStatistics();
 
   // Write barrier support for address[offset] = o.
   INLINE(void RecordWrite(Address address, int offset));
 
   // Write barrier support for address[start : start + len[ = o.
   INLINE(void RecordWrites(Address address, int start, int len));
 
   enum HeapState { NOT_IN_GC, SCAVENGE, MARK_COMPACT };
@@ skipping 440 matching lines @@
 
   void InitializeWeakObjectToCodeTable() {
     set_weak_object_to_code_table(undefined_value());
   }
 
   void EnsureWeakObjectToCodeTable();
 
   static void FatalProcessOutOfMemory(const char* location,
                                       bool take_snapshot = false);
 
+  // This event is triggered after successful allocation of a new object made
+  // by runtime. Allocations of target space for object evacuation do not
+  // trigger the event. In order to track ALL allocations one must turn off
+  // FLAG_inline_new and FLAG_use_allocation_folding.
+  inline void OnAllocationEvent(HeapObject* object, int size_in_bytes);
+
+  // This event is triggered after object is moved to a new place.
+  inline void OnMoveEvent(HeapObject* target,
+                          HeapObject* source,
+                          int size_in_bytes);
+
  protected:
   // Methods made available to tests.
 
   // Allocates a JS Map in the heap.
   MUST_USE_RESULT AllocationResult AllocateMap(
       InstanceType instance_type,
       int instance_size,
       ElementsKind elements_kind = TERMINAL_FAST_ELEMENTS_KIND);
 
   // Allocates and initializes a new JavaScript object based on a
@@ skipping 95 matching lines @@
   CellSpace* cell_space_;
   PropertyCellSpace* property_cell_space_;
   LargeObjectSpace* lo_space_;
   HeapState gc_state_;
   int gc_post_processing_depth_;
   Address new_space_top_after_last_gc_;
 
   // Returns the amount of external memory registered since last global gc.
   int64_t PromotedExternalMemorySize();
 
-  unsigned int ms_count_;  // how many mark-sweep collections happened
-  unsigned int gc_count_;  // how many gc happened
+  // How many "runtime allocations" happened.
+  uint32_t allocations_count_;
+
+  // Running hash over allocations performed.
+  uint32_t raw_allocations_hash_;
+
+  // Countdown counter, dumps allocation hash when 0.
+  uint32_t dump_allocations_hash_countdown_;
+
+  // How many mark-sweep collections happened.
+  unsigned int ms_count_;
+
+  // How many gc happened.
+  unsigned int gc_count_;
 
   // For post mortem debugging.
   static const int kRememberedUnmappedPages = 128;
   int remembered_unmapped_pages_index_;
   Address remembered_unmapped_pages_[kRememberedUnmappedPages];
 
   // Total length of the strings we failed to flatten since the last GC.
   int unflattened_strings_length_;
 
 #define ROOT_ACCESSOR(type, name, camel_name)                                  \
@@ skipping 513 matching lines @@
 
   void set_weak_object_to_code_table(Object* value) {
     ASSERT(!InNewSpace(value));
     weak_object_to_code_table_ = value;
   }
 
   Object** weak_object_to_code_table_address() {
     return &weak_object_to_code_table_;
   }
 
+  inline void UpdateAllocationsHash(HeapObject* object);
+  inline void UpdateAllocationsHash(uint32_t value);
+  inline void PrintAlloctionsHash();
+
   static const int kInitialStringTableSize = 2048;
   static const int kInitialEvalCacheSize = 64;
   static const int kInitialNumberStringCacheSize = 256;
 
   // Object counts and used memory by InstanceType
   size_t object_counts_[OBJECT_STATS_COUNT];
   size_t object_counts_last_time_[OBJECT_STATS_COUNT];
   size_t object_sizes_[OBJECT_STATS_COUNT];
   size_t object_sizes_last_time_[OBJECT_STATS_COUNT];
 
@@ skipping 681 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_