[heap] Move to page lookups for SemiSpace, NewSpace, and Heap containment methods

src/heap/spaces.h

 // Copyright 2011 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_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
 #include "src/allocation.h"
 #include "src/atomic-utils.h"
 #include "src/base/atomicops.h"
@@ skipping 1923 matching lines @@
   // addresses is not big enough to contain a single page-aligned page, a
   // fresh chunk will be allocated.
   bool SetUp();
 
   // Returns true if the space has been successfully set up and not
   // subsequently torn down.
   bool HasBeenSetUp();
 
   // Checks whether an object/address is in this space.
   inline bool Contains(Address a);
-  inline bool Contains(HeapObject* o);
-  // Unlike Contains() methods it is safe to call this one even for addresses
-  // of unmapped memory.
-  bool ContainsSafe(Address addr);
+  inline bool Contains(Object* o);
+  bool ContainsSlow(Address addr);
 
   // Given an address occupied by a live object, return that object if it is
   // in this space, or a Smi if it is not.  The implementation iterates over
   // objects in the page containing the address, the cost is linear in the
   // number of objects in the page.  It may be slow.
   Object* FindObject(Address addr);
 
   // During boot the free_space_map is created, and afterwards we may need
   // to write it into the free list nodes that were already created.
   void RepairFreeListsAfterDeserialization();
@@ skipping 356 matching lines @@
  public:
   static void Swap(SemiSpace* from, SemiSpace* to);
 
   SemiSpace(Heap* heap, SemiSpaceId semispace)
       : Space(heap, NEW_SPACE, NOT_EXECUTABLE),
         current_capacity_(0),
         maximum_capacity_(0),
         minimum_capacity_(0),
         start_(nullptr),
         age_mark_(nullptr),
-        address_mask_(0),
-        object_mask_(0),
-        object_expected_(0),
         committed_(false),
         id_(semispace),
         anchor_(this),
         current_page_(nullptr) {}
 
+  inline bool Contains(HeapObject* o);
+  inline bool Contains(Object* o);
+  inline bool ContainsSlow(Address a);
+
   // Creates a space in the young generation. The constructor does not
-  // allocate memory from the OS.  A SemiSpace is given a contiguous chunk of
-  // memory of size {initial_capacity} when set up.
+  // allocate memory from the OS.
   void SetUp(Address start, int initial_capacity, int maximum_capacity);
 
   // Tear down the space.  Heap memory was not allocated by the space, so it
   // is not deallocated here.
   void TearDown();
 
   // True if the space has been set up but not torn down.
   bool HasBeenSetUp() { return start_ != nullptr; }
 
   // Grow the semispace to the new capacity.  The new capacity
@@ skipping 28 matching lines @@
     return true;
   }
 
   // Resets the space to using the first page.
   void Reset();
 
   // Age mark accessors.
   Address age_mark() { return age_mark_; }
   void set_age_mark(Address mark);
 
-  // True if the address is in the address range of this semispace (not
-  // necessarily below the allocation pointer).
-  bool Contains(Address a) {
-    return (reinterpret_cast<uintptr_t>(a) & address_mask_) ==
-           reinterpret_cast<uintptr_t>(start_);
-  }
-
-  // True if the object is a heap object in the address range of this
-  // semispace (not necessarily below the allocation pointer).
-  bool Contains(Object* o) {
-    return (reinterpret_cast<uintptr_t>(o) & object_mask_) == object_expected_;
-  }
-
   bool is_committed() { return committed_; }
   bool Commit();
   bool Uncommit();
 
   NewSpacePage* first_page() { return anchor_.next_page(); }
   NewSpacePage* current_page() { return current_page_; }
 
   // Returns the current total capacity of the semispace.
   int current_capacity() { return current_capacity_; }
 
@@ skipping 38 matching lines @@
   virtual void Verify();
 #endif
 
  private:
   NewSpacePage* anchor() { return &anchor_; }
 
   void set_current_capacity(int new_capacity) {
     current_capacity_ = new_capacity;
   }
 
-  // Flips the semispace between being from-space and to-space. Copies the flags
-  // into the masked positions on all pages in the space.
-  void FlipPages(intptr_t flags, intptr_t flag_mask);
+  // Copies the flags into the masked positions on all pages in the space.
+  void FixPagesFlags(intptr_t flags, intptr_t flag_mask);
 
   // The currently committed space capacity.
   int current_capacity_;
 
   // The maximum capacity that can be used by this space.
   int maximum_capacity_;
 
   // The mimnimum capacity for the space. A space cannot shrink below this size.
   int minimum_capacity_;
 
   // The start address of the space.
   Address start_;
   // Used to govern object promotion during mark-compact collection.
   Address age_mark_;
 
-  // Masks and comparison values to test for containment in this semispace.
-  uintptr_t address_mask_;
-  uintptr_t object_mask_;
-  uintptr_t object_expected_;
-
   bool committed_;
   SemiSpaceId id_;
 
   NewSpacePage anchor_;
   NewSpacePage* current_page_;
 
   friend class SemiSpaceIterator;
   friend class NewSpacePageIterator;
 };
 
@@ skipping 61 matching lines @@
  public:
   // Constructor.
   explicit NewSpace(Heap* heap)
       : Space(heap, NEW_SPACE, NOT_EXECUTABLE),
         to_space_(heap, kToSpace),
         from_space_(heap, kFromSpace),
         reservation_(),
         top_on_previous_step_(0),
         inline_allocation_observers_paused_(false) {}
 
+  inline bool Contains(HeapObject* o);
+  inline bool ContainsSlow(Address a);
+  inline bool Contains(Object* o);
+
   // Sets up the new space using the given chunk.
   bool SetUp(int reserved_semispace_size_, int max_semi_space_size);
 
   // Tears down the space.  Heap memory was not allocated by the space, so it
   // is not deallocated here.
   void TearDown();
 
   // True if the space has been set up but not torn down.
   bool HasBeenSetUp() {
     return to_space_.HasBeenSetUp() && from_space_.HasBeenSetUp();
   }
 
   // Flip the pair of spaces.
   void Flip();
 
   // Grow the capacity of the semispaces.  Assumes that they are not at
   // their maximum capacity.
   void Grow();
 
   // Shrink the capacity of the semispaces.
   void Shrink();
 
-  // True if the address or object lies in the address range of either
-  // semispace (not necessarily below the allocation pointer).
-  bool Contains(Address a) {
-    return (reinterpret_cast<uintptr_t>(a) & address_mask_) ==
-           reinterpret_cast<uintptr_t>(start_);
-  }
-
-  bool Contains(Object* o) {
-    Address a = reinterpret_cast<Address>(o);
-    return (reinterpret_cast<uintptr_t>(a) & object_mask_) == object_expected_;
-  }
-
   // Return the allocated bytes in the active semispace.
   intptr_t Size() override {
     return pages_used_ * NewSpacePage::kAreaSize +
            static_cast<int>(top() - to_space_.page_low());
   }
 
   // The same, but returning an int.  We have to have the one that returns
   // intptr_t because it is inherited, but if we know we are dealing with the
   // new space, which can't get as big as the other spaces then this is useful:
   int SizeAsInt() { return static_cast<int>(Size()); }
@@ skipping 78 matching lines @@
   Address bottom() { return to_space_.space_start(); }
 
   // Get the age mark of the inactive semispace.
   Address age_mark() { return from_space_.age_mark(); }
   // Set the age mark in the active semispace.
   void set_age_mark(Address mark) { to_space_.set_age_mark(mark); }
 
   // The start address of the space and a bit mask. Anding an address in the
   // new space with the mask will result in the start address.
   Address start() { return start_; }
-  uintptr_t mask() { return address_mask_; }
-
-  INLINE(uint32_t AddressToMarkbitIndex(Address addr)) {
-    DCHECK(Contains(addr));
-    DCHECK(IsAligned(OffsetFrom(addr), kPointerSize) ||
-           IsAligned(OffsetFrom(addr) - 1, kPointerSize));
-    return static_cast<uint32_t>(addr - start_) >> kPointerSizeLog2;
-  }
-
-  INLINE(Address MarkbitIndexToAddress(uint32_t index)) {
-    return reinterpret_cast<Address>(index << kPointerSizeLog2);
-  }
 
   // The allocation top and limit address.
   Address* allocation_top_address() { return allocation_info_.top_address(); }
 
   // The allocation limit address.
   Address* allocation_limit_address() {
     return allocation_info_.limit_address();
   }
 
   MUST_USE_RESULT INLINE(AllocationResult AllocateRawAligned(
@@ skipping 32 matching lines @@
   // same page, so FromSpaceStart() might be above FromSpaceEnd().
   Address FromSpacePageLow() { return from_space_.page_low(); }
   Address FromSpacePageHigh() { return from_space_.page_high(); }
   Address FromSpaceStart() { return from_space_.space_start(); }
   Address FromSpaceEnd() { return from_space_.space_end(); }
 
   // Get the extent of the active semispace's pages' memory.
   Address ToSpaceStart() { return to_space_.space_start(); }
   Address ToSpaceEnd() { return to_space_.space_end(); }
 
-  inline bool ToSpaceContains(Address address) {
-    return to_space_.Contains(address);
-  }
-  inline bool FromSpaceContains(Address address) {
-    return from_space_.Contains(address);
-  }
-
-  // True if the object is a heap object in the address range of the
-  // respective semispace (not necessarily below the allocation pointer of the
-  // semispace).
-  inline bool ToSpaceContains(Object* o) { return to_space_.Contains(o); }
-  inline bool FromSpaceContains(Object* o) { return from_space_.Contains(o); }
+  inline bool ToSpaceContainsSlow(Address a);
+  inline bool FromSpaceContainsSlow(Address a);
+  inline bool ToSpaceContains(Object* o);
+  inline bool FromSpaceContains(Object* o);
 
   // Try to switch the active semispace to a new, empty, page.
   // Returns false if this isn't possible or reasonable (i.e., there
   // are no pages, or the current page is already empty), or true
   // if successful.
   bool AddFreshPage();
   bool AddFreshPageSynchronized();
 
 #ifdef VERIFY_HEAP
   // Verify the active semispace.
@@ skipping 43 matching lines @@
   uintptr_t chunk_size_;
 
   // The semispaces.
   SemiSpace to_space_;
   SemiSpace from_space_;
   base::VirtualMemory reservation_;
   int pages_used_;
 
   // Start address and bit mask for containment testing.
   Address start_;
-  uintptr_t address_mask_;
-  uintptr_t object_mask_;
-  uintptr_t object_expected_;
 
   // Allocation pointer and limit for normal allocation and allocation during
   // mark-compact collection.
   AllocationInfo allocation_info_;
 
   // When inline allocation stepping is active, either because of incremental
   // marking or because of idle scavenge, we 'interrupt' inline allocation every
   // once in a while. This is done by setting allocation_info_.limit to be lower
   // than the actual limit and and increasing it in steps to guarantee that the
   // observers are notified periodically.
@@ skipping 192 matching lines @@
   LargePage* FindPage(Address a);
 
   // Clears the marking state of live objects.
   void ClearMarkingStateOfLiveObjects();
 
   // Frees unmarked objects.
   void FreeUnmarkedObjects();
 
   // Checks whether a heap object is in this space; O(1).
   bool Contains(HeapObject* obj);
-  bool Contains(Address address);
+  // Checks whether an address is in the object area in this space. Iterates
+  // all objects in the space. May be slow.
+  bool ContainsSlow(Address addr) { return FindObject(addr)->IsHeapObject(); }
 
   // Checks whether the space is empty.
   bool IsEmpty() { return first_page_ == NULL; }
 
   LargePage* first_page() { return first_page_; }
 
 #ifdef VERIFY_HEAP
   virtual void Verify();
 #endif
 
 #ifdef DEBUG
   void Print() override;
   void ReportStatistics();
   void CollectCodeStatistics();
 #endif
-  // Checks whether an address is in the object area in this space.  It
-  // iterates all objects in the space. May be slow.
-  bool SlowContains(Address addr) { return FindObject(addr)->IsHeapObject(); }
 
  private:
   // The head of the linked list of large object chunks.
   LargePage* first_page_;
   intptr_t size_;          // allocated bytes
   int page_count_;         // number of chunks
   intptr_t objects_size_;  // size of objects
   // Map MemoryChunk::kAlignment-aligned chunks to large pages covering them
   HashMap chunk_map_;
 
@@ skipping 44 matching lines @@
     count = 0;
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_