[heap] Fix address space leak in Unmapper

src/heap/spaces.h

Index: src/heap/spaces.h
diff --git a/src/heap/spaces.h b/src/heap/spaces.h
index 066bbfa7cdbff723921007e7dd0f2f47fb216613..1dbcbd93da72774e1fbca3597aa06e0fb6690ec8 100644
--- a/src/heap/spaces.h
+++ b/src/heap/spaces.h
@@ -1097,7 +1097,7 @@ class SkipList {
 // 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.
@@ -1149,6 +1149,11 @@ class MemoryAllocator {
       kNumberOfChunkQueues,
     };
 
+    enum class FreeMode {
+      kUncommitPooled,
+      kReleasePooled,
+    };
+
     template <ChunkQueueType type>
     void AddMemoryChunkSafe(MemoryChunk* chunk) {
       base::LockGuard<base::Mutex> guard(&mutex_);
@@ -1170,6 +1175,7 @@ class MemoryAllocator {
     }
 
     void ReconsiderDelayedChunks();
+    template <FreeMode mode>
     void PerformFreeMemoryOnQueuedChunks();
 
     base::Mutex mutex_;
@@ -1192,6 +1198,7 @@ class MemoryAllocator {
 
   enum FreeMode {
     kFull,
+    kAlreadyPooled,
     kPreFreeAndQueue,
     kPooledAndQueue,
   };
@@ -1381,6 +1388,15 @@ class MemoryAllocator {
   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
@@ -1648,7 +1664,7 @@ class AllocationStats BASE_EMBEDDED {
 //   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.
@@ -1885,7 +1901,7 @@ class LocalAllocationBuffer {
   AllocationInfo allocation_info_;
 };
 
-class PagedSpace : public Space {
+class V8_EXPORT_PRIVATE PagedSpace : NON_EXPORTED_BASE(public Space) {
  public:
   typedef PageIterator iterator;