[heap] Fix address space leak in Unmapper

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 <list>
 #include <memory>
 #include <unordered_set>
@@ skipping 1079 matching lines @@
   STATIC_ASSERT(Page::kPageSize % kRegionSize == 0);
 
   Address starts_[kSize];
 };
 
 
 // ----------------------------------------------------------------------------
 // A space acquires chunks of memory from the operating system. The memory
 // allocator allocates and deallocates pages for the paged heap spaces and large
 // pages for large object space.
-class MemoryAllocator {
+class V8_EXPORT_PRIVATE MemoryAllocator {
  public:
   // Unmapper takes care of concurrently unmapping and uncommitting memory
   // chunks.
   class Unmapper {
    public:
     class UnmapFreeMemoryTask;
 
     explicit Unmapper(MemoryAllocator* allocator)
         : allocator_(allocator),
           pending_unmapping_tasks_semaphore_(0),
@@ skipping 31 matching lines @@
 
    private:
     enum ChunkQueueType {
       kRegular,     // Pages of kPageSize that do not live in a CodeRange and
                     // can thus be used for stealing.
       kNonRegular,  // Large chunks and executable chunks.
       kPooled,      // Pooled chunks, already uncommited and ready for reuse.
       kNumberOfChunkQueues,
     };
 
+    enum class FreeMode {
+      kUncommitPooled,
+      kReleasePooled,
+    };
+
     template <ChunkQueueType type>
     void AddMemoryChunkSafe(MemoryChunk* chunk) {
       base::LockGuard<base::Mutex> guard(&mutex_);
       if (type != kRegular || allocator_->CanFreeMemoryChunk(chunk)) {
         chunks_[type].push_back(chunk);
       } else {
         DCHECK_EQ(type, kRegular);
         delayed_regular_chunks_.push_back(chunk);
       }
     }
 
     template <ChunkQueueType type>
     MemoryChunk* GetMemoryChunkSafe() {
       base::LockGuard<base::Mutex> guard(&mutex_);
       if (chunks_[type].empty()) return nullptr;
       MemoryChunk* chunk = chunks_[type].front();
       chunks_[type].pop_front();
       return chunk;
     }
 
     void ReconsiderDelayedChunks();
+    template <FreeMode mode>
     void PerformFreeMemoryOnQueuedChunks();
 
     base::Mutex mutex_;
     MemoryAllocator* allocator_;
     std::list<MemoryChunk*> chunks_[kNumberOfChunkQueues];
     // Delayed chunks cannot be processed in the current unmapping cycle because
     // of dependencies such as an active sweeper.
     // See MemoryAllocator::CanFreeMemoryChunk.
     std::list<MemoryChunk*> delayed_regular_chunks_;
     base::Semaphore pending_unmapping_tasks_semaphore_;
     intptr_t concurrent_unmapping_tasks_active_;
 
     friend class MemoryAllocator;
   };
 
   enum AllocationMode {
     kRegular,
     kPooled,
   };
 
   enum FreeMode {
     kFull,
+    kAlreadyPooled,
     kPreFreeAndQueue,
     kPooledAndQueue,
   };
 
   static size_t CodePageGuardStartOffset();
 
   static size_t CodePageGuardSize();
 
   static size_t CodePageAreaStartOffset();
 
@@ skipping 169 matching lines @@
   base::AtomicValue<void*> highest_ever_allocated_;
 
   base::VirtualMemory last_chunk_;
   Unmapper unmapper_;
 
   friend class TestCodeRangeScope;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(MemoryAllocator);
 };
 
+extern template Page*
+MemoryAllocator::AllocatePage<MemoryAllocator::kRegular, PagedSpace>(
+    size_t size, PagedSpace* owner, Executability executable);
+extern template Page*
+MemoryAllocator::AllocatePage<MemoryAllocator::kRegular, SemiSpace>(
+    size_t size, SemiSpace* owner, Executability executable);
+extern template Page*
+MemoryAllocator::AllocatePage<MemoryAllocator::kPooled, SemiSpace>(
+    size_t size, SemiSpace* owner, Executability executable);
 
 // -----------------------------------------------------------------------------
 // Interface for heap object iterator to be implemented by all object space
 // object iterators.
 //
 // NOTE: The space specific object iterators also implements the own next()
 //       method which is used to avoid using virtual functions
 //       iterating a specific space.
 
 class V8_EXPORT_PRIVATE ObjectIterator : public Malloced {
@@ skipping 247 matching lines @@
 // 11-31 words (tiny): The tiny blocks are only used for allocation, when
 //   categories >= small do not have entries anymore.
 // 32-255 words (small): Used for allocating free space between 1-31 words in
 //   size.
 // 256-2047 words (medium): Used for allocating free space between 32-255 words
 //   in size.
 // 1048-16383 words (large): Used for allocating free space between 256-2047
 //   words in size.
 // At least 16384 words (huge): This list is for objects of 2048 words or
 //   larger. Empty pages are also added to this list.
-class FreeList {
+class V8_EXPORT_PRIVATE FreeList {
  public:
   // This method returns how much memory can be allocated after freeing
   // maximum_freed memory.
   static inline size_t GuaranteedAllocatable(size_t maximum_freed) {
     if (maximum_freed <= kTiniestListMax) {
       // Since we are not iterating over all list entries, we cannot guarantee
       // that we can find the maximum freed block in that free list.
       return 0;
     } else if (maximum_freed <= kTinyListMax) {
       return kTinyAllocationMax;
@@ skipping 216 matching lines @@
 
  private:
   LocalAllocationBuffer(Heap* heap, AllocationInfo allocation_info);
 
   void Close();
 
   Heap* heap_;
   AllocationInfo allocation_info_;
 };
 
-class PagedSpace : public Space {
+class V8_EXPORT_PRIVATE PagedSpace : NON_EXPORTED_BASE(public Space) {
  public:
   typedef PageIterator iterator;
 
   static const intptr_t kCompactionMemoryWanted = 500 * KB;
 
   // Creates a space with an id.
   PagedSpace(Heap* heap, AllocationSpace id, Executability executable);
 
   ~PagedSpace() override { TearDown(); }
 
@@ skipping 998 matching lines @@
   PageIterator old_iterator_;
   PageIterator code_iterator_;
   PageIterator map_iterator_;
   LargePageIterator lo_iterator_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_