Upgrade V8 to 3.7.0

1 files changed, 248 insertions, 0 deletions

diff --git a/deps/v8/src/store-buffer.h b/deps/v8/src/store-buffer.h
new file mode 100644
index 000000000..61b97d9e6
--- /dev/null
+++ b/deps/v8/src/store-buffer.h
@@ -0,0 +1,248 @@
+// Copyright 2011 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_STORE_BUFFER_H_
+#define V8_STORE_BUFFER_H_
+
+#include "allocation.h"
+#include "checks.h"
+#include "globals.h"
+#include "platform.h"
+#include "v8globals.h"
+
+namespace v8 {
+namespace internal {
+
+class StoreBuffer;
+
+typedef void (*ObjectSlotCallback)(HeapObject** from, HeapObject* to);
+
+typedef void (StoreBuffer::*RegionCallback)(
+    Address start, Address end, ObjectSlotCallback slot_callback);
+
+// Used to implement the write barrier by collecting addresses of pointers
+// between spaces.
+class StoreBuffer {
+ public:
+  explicit StoreBuffer(Heap* heap);
+
+  static void StoreBufferOverflow(Isolate* isolate);
+
+  inline Address TopAddress();
+
+  void Setup();
+  void TearDown();
+
+  // This is used by the mutator to enter addresses into the store buffer.
+  inline void Mark(Address addr);
+
+  // This is used by the heap traversal to enter the addresses into the store
+  // buffer that should still be in the store buffer after GC.  It enters
+  // addresses directly into the old buffer because the GC starts by wiping the
+  // old buffer and thereafter only visits each cell once so there is no need
+  // to attempt to remove any dupes.  During the first part of a GC we
+  // are using the store buffer to access the old spaces and at the same time
+  // we are rebuilding the store buffer using this function.  There is, however
+  // no issue of overwriting the buffer we are iterating over, because this
+  // stage of the scavenge can only reduce the number of addresses in the store
+  // buffer (some objects are promoted so pointers to them do not need to be in
+  // the store buffer).  The later parts of the GC scan the pages that are
+  // exempt from the store buffer and process the promotion queue.  These steps
+  // can overflow this buffer.  We check for this and on overflow we call the
+  // callback set up with the StoreBufferRebuildScope object.
+  inline void EnterDirectlyIntoStoreBuffer(Address addr);
+
+  // Iterates over all pointers that go from old space to new space.  It will
+  // delete the store buffer as it starts so the callback should reenter
+  // surviving old-to-new pointers into the store buffer to rebuild it.
+  void IteratePointersToNewSpace(ObjectSlotCallback callback);
+
+  static const int kStoreBufferOverflowBit = 1 << 16;
+  static const int kStoreBufferSize = kStoreBufferOverflowBit;
+  static const int kStoreBufferLength = kStoreBufferSize / sizeof(Address);
+  static const int kOldStoreBufferLength = kStoreBufferLength * 16;
+  static const int kHashMapLengthLog2 = 12;
+  static const int kHashMapLength = 1 << kHashMapLengthLog2;
+
+  void Compact();
+
+  void GCPrologue();
+  void GCEpilogue();
+
+  Object*** Limit() { return reinterpret_cast<Object***>(old_limit_); }
+  Object*** Start() { return reinterpret_cast<Object***>(old_start_); }
+  Object*** Top() { return reinterpret_cast<Object***>(old_top_); }
+  void SetTop(Object*** top) {
+    ASSERT(top >= Start());
+    ASSERT(top <= Limit());
+    old_top_ = reinterpret_cast<Address*>(top);
+  }
+
+  bool old_buffer_is_sorted() { return old_buffer_is_sorted_; }
+  bool old_buffer_is_filtered() { return old_buffer_is_filtered_; }
+
+  // Goes through the store buffer removing pointers to things that have
+  // been promoted.  Rebuilds the store buffer completely if it overflowed.
+  void SortUniq();
+
+  void HandleFullness();
+  void Verify();
+
+  bool PrepareForIteration();
+
+#ifdef DEBUG
+  void Clean();
+  // Slow, for asserts only.
+  bool CellIsInStoreBuffer(Address cell);
+#endif
+
+  void Filter(int flag);
+
+ private:
+  Heap* heap_;
+
+  // The store buffer is divided up into a new buffer that is constantly being
+  // filled by mutator activity and an old buffer that is filled with the data
+  // from the new buffer after compression.
+  Address* start_;
+  Address* limit_;
+
+  Address* old_start_;
+  Address* old_limit_;
+  Address* old_top_;
+
+  bool old_buffer_is_sorted_;
+  bool old_buffer_is_filtered_;
+  bool during_gc_;
+  // The garbage collector iterates over many pointers to new space that are not
+  // handled by the store buffer.  This flag indicates whether the pointers
+  // found by the callbacks should be added to the store buffer or not.
+  bool store_buffer_rebuilding_enabled_;
+  StoreBufferCallback callback_;
+  bool may_move_store_buffer_entries_;
+
+  VirtualMemory* virtual_memory_;
+  uintptr_t* hash_map_1_;
+  uintptr_t* hash_map_2_;
+
+  void CheckForFullBuffer();
+  void Uniq();
+  void ZapHashTables();
+  bool HashTablesAreZapped();
+  void ExemptPopularPages(int prime_sample_step, int threshold);
+
+  void FindPointersToNewSpaceInRegion(Address start,
+                                      Address end,
+                                      ObjectSlotCallback slot_callback);
+
+  // For each region of pointers on a page in use from an old space call
+  // visit_pointer_region callback.
+  // If either visit_pointer_region or callback can cause an allocation
+  // in old space and changes in allocation watermark then
+  // can_preallocate_during_iteration should be set to true.
+  void IteratePointersOnPage(
+      PagedSpace* space,
+      Page* page,
+      RegionCallback region_callback,
+      ObjectSlotCallback slot_callback);
+
+  void FindPointersToNewSpaceInMaps(
+    Address start,
+    Address end,
+    ObjectSlotCallback slot_callback);
+
+  void FindPointersToNewSpaceInMapsRegion(
+    Address start,
+    Address end,
+    ObjectSlotCallback slot_callback);
+
+  void FindPointersToNewSpaceOnPage(
+    PagedSpace* space,
+    Page* page,
+    RegionCallback region_callback,
+    ObjectSlotCallback slot_callback);
+
+  void IteratePointersInStoreBuffer(ObjectSlotCallback slot_callback);
+
+#ifdef DEBUG
+  void VerifyPointers(PagedSpace* space, RegionCallback region_callback);
+  void VerifyPointers(LargeObjectSpace* space);
+#endif
+
+  friend class StoreBufferRebuildScope;
+  friend class DontMoveStoreBufferEntriesScope;
+};
+
+
+class StoreBufferRebuildScope {
+ public:
+  explicit StoreBufferRebuildScope(Heap* heap,
+                                   StoreBuffer* store_buffer,
+                                   StoreBufferCallback callback)
+      : heap_(heap),
+        store_buffer_(store_buffer),
+        stored_state_(store_buffer->store_buffer_rebuilding_enabled_),
+        stored_callback_(store_buffer->callback_) {
+    store_buffer_->store_buffer_rebuilding_enabled_ = true;
+    store_buffer_->callback_ = callback;
+    (*callback)(heap, NULL, kStoreBufferStartScanningPagesEvent);
+  }
+
+  ~StoreBufferRebuildScope() {
+    store_buffer_->callback_ = stored_callback_;
+    store_buffer_->store_buffer_rebuilding_enabled_ = stored_state_;
+    store_buffer_->CheckForFullBuffer();
+  }
+
+ private:
+  Heap* heap_;
+  StoreBuffer* store_buffer_;
+  bool stored_state_;
+  StoreBufferCallback stored_callback_;
+};
+
+
+class DontMoveStoreBufferEntriesScope {
+ public:
+  explicit DontMoveStoreBufferEntriesScope(StoreBuffer* store_buffer)
+      : store_buffer_(store_buffer),
+        stored_state_(store_buffer->may_move_store_buffer_entries_) {
+    store_buffer_->may_move_store_buffer_entries_ = false;
+  }
+
+  ~DontMoveStoreBufferEntriesScope() {
+    store_buffer_->may_move_store_buffer_entries_ = stored_state_;
+  }
+
+ private:
+  StoreBuffer* store_buffer_;
+  bool stored_state_;
+};
+
+} }  // namespace v8::internal
+
+#endif  // V8_STORE_BUFFER_H_