- Consolidate code into the old generation.

vm/pages.h

 // Copyright (c) 2011, 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 VM_PAGES_H_
 #define VM_PAGES_H_
 
 #include <map>
 
 #include "vm/freelist.h"
 #include "vm/globals.h"
 #include "vm/virtual_memory.h"
 
 namespace dart {
 
 // Forward declarations.
 class Heap;
 class ObjectPointerVisitor;
 
 // An aligned page containing old generation objects. Alignment is used to be
 // able to get to a HeapPage header quickly based on a pointer to an object.
 class HeapPage {
  public:
+  enum PageType {
+    kData = 0,
+    kExecutable,
+    kNumPageTypes
+  };
+
   HeapPage* next() const { return next_; }
   void set_next(HeapPage* next) { next_ = next; }
 
   bool Contains(uword addr) {
     return memory_->Contains(addr);
   }
 
   uword object_start() const {
-    return (reinterpret_cast<uword>(this) + sizeof(HeapPage));
+    return (reinterpret_cast<uword>(this) +
+            Utils::RoundUp(sizeof(HeapPage), kObjectAlignment));
   }
   uword object_end() const {
     return object_end_;
   }
 
   void set_used(uword used) { used_ = used; }
   uword used() const { return used_; }
   void AddUsed(uword size) {
     used_ += size;
   }
 
+  PageType type() const {
+    return executable_ ? kExecutable : kData;
+  }
+
   void VisitObjects(ObjectVisitor* visitor) const;
   void VisitObjectPointers(ObjectPointerVisitor* visitor) const;
 
   RawObject* FindObject(FindObjectVisitor* visitor) const;
 
   void WriteProtect(bool read_only);
 
  private:
   void set_object_end(uword val) {
     ASSERT((val & kObjectAlignmentMask) == kOldObjectAlignmentOffset);
     object_end_ = val;
   }
 
-  static HeapPage* Initialize(VirtualMemory* memory, bool is_executable);
-  static HeapPage* Allocate(intptr_t size, bool is_executable);
+  static HeapPage* Initialize(VirtualMemory* memory, PageType type);
+  static HeapPage* Allocate(intptr_t size, PageType type);
 
   // Deallocate the virtual memory backing this page. The page pointer to this
   // page becomes immediately inaccessible.
   void Deallocate();
 
   VirtualMemory* memory_;
   HeapPage* next_;
   uword used_;
   uword object_end_;
+  bool executable_;

[siva, 2012/10/25 22:29:52]

should this just be
PageType type_;

[Ivan Posva, 2012/10/25 23:45:41]

If it really is needed, then I will switch this to a bit field. Leaving it as is
for now.

 
   friend class PageSpace;
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(HeapPage);
 };
 
 
 // The history holds the timing information of the last garbage collection
 // runs.
@@ skipping 72 matching lines @@
  public:
   // TODO(iposva): Determine heap sizes and tune the page size accordingly.
   static const intptr_t kPageSize = 256 * KB;
   static const intptr_t kPageAlignment = kPageSize;
 
   enum GrowthPolicy {
     kControlGrowth,
     kForceGrowth
   };
 
-  PageSpace(Heap* heap, intptr_t max_capacity, bool is_executable = false);
+  PageSpace(Heap* heap, intptr_t max_capacity);
   ~PageSpace();
 
-  uword TryAllocate(intptr_t size);
-  uword TryAllocate(intptr_t size, GrowthPolicy growth_policy);
+  uword TryAllocate(intptr_t size,
+                    HeapPage::PageType type = HeapPage::kData,
+                    GrowthPolicy growth_policy = kControlGrowth);
 
   intptr_t in_use() const { return in_use_; }
   intptr_t capacity() const { return capacity_; }
 
   bool Contains(uword addr) const;
+  bool Contains(uword addr, HeapPage::PageType type) const;
   bool IsValidAddress(uword addr) const {
     return Contains(addr);
   }
   static bool IsPageAllocatableSize(intptr_t size) {
     return size <= kAllocatablePageSize;
   }
 
   void VisitObjects(ObjectVisitor* visitor) const;
   void VisitObjectPointers(ObjectPointerVisitor* visitor) const;
 
@@ skipping 21 matching lines @@
 
   void* GetPeer(RawObject* raw_obj);
 
   int64_t PeerCount() const;
 
   PeerTable* GetPeerTable() { return &peer_table_; }
 
  private:
   static const intptr_t kAllocatablePageSize = kPageSize - sizeof(HeapPage);
 
-  HeapPage* AllocatePage();
+  HeapPage* AllocatePage(HeapPage::PageType type);
   void FreePage(HeapPage* page, HeapPage* previous_page);
-  HeapPage* AllocateLargePage(intptr_t size);
+  HeapPage* AllocateLargePage(intptr_t size, HeapPage::PageType type);
   void FreeLargePage(HeapPage* page, HeapPage* previous_page);
   void FreePages(HeapPage* pages);
 
   static intptr_t LargePageSizeFor(intptr_t size);
 
   bool CanIncreaseCapacity(intptr_t increase) {
     ASSERT(capacity_ <= max_capacity_);
     return increase <= (max_capacity_ - capacity_);
   }
 
-  FreeList freelist_;
+  FreeList freelist_[HeapPage::kNumPageTypes];
 
   Heap* heap_;
 
   HeapPage* pages_;
   HeapPage* pages_tail_;
   HeapPage* large_pages_;
 
   PeerTable peer_table_;
 
   // Various sizes being tracked for this generation.
   intptr_t max_capacity_;
   intptr_t capacity_;
   intptr_t in_use_;
 
   // Old-gen GC cycle count.
   int count_;
 
-  bool is_executable_;
-
   // Keep track whether a MarkSweep is currently running.
   bool sweeping_;
 
   PageSpaceController page_space_controller_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PageSpace);
 };
 
 }  // namespace dart
 
 #endif  // VM_PAGES_H_