content: Cancel all DeletedDiscardableSharedMemory callbacks in dtor.

content/child/child_discardable_shared_memory_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/child/child_discardable_shared_memory_manager.h"
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
 #include "base/debug/crash_logging.h"
 #include "base/memory/discardable_shared_memory.h"
@@ skipping 35 matching lines @@
     return reinterpret_cast<void*>(span_->start() * base::GetPageSize());
   }
 
  private:
   ChildDiscardableSharedMemoryManager* manager_;
   scoped_ptr<DiscardableSharedMemoryHeap::Span> span_;
 
   DISALLOW_COPY_AND_ASSIGN(DiscardableMemoryShmemChunkImpl);
 };
 
-void DeletedDiscardableSharedMemory(scoped_refptr<ThreadSafeSender> sender,
-                                    DiscardableSharedMemoryId id) {
-  sender->Send(new ChildProcessHostMsg_DeletedDiscardableSharedMemory(id));
-}
-
 }  // namespace
 
 ChildDiscardableSharedMemoryManager::ChildDiscardableSharedMemoryManager(
     ThreadSafeSender* sender)
-    : heap_(base::GetPageSize()), sender_(sender) {
+    : heap_(base::GetPageSize()), sender_(sender), weak_ptr_factory_(this) {
 }
 
 ChildDiscardableSharedMemoryManager::~ChildDiscardableSharedMemoryManager() {
+  // Cancel all DeletedDiscardableSharedMemory callbacks.
+  weak_ptr_factory_.InvalidateWeakPtrs();
+
   // TODO(reveman): Determine if this DCHECK can be enabled. crbug.com/430533
   // DCHECK_EQ(heap_.GetSize(), heap_.GetSizeOfFreeLists());
   if (heap_.GetSize())
     MemoryUsageChanged(0, 0);
 }
 
 scoped_ptr<base::DiscardableMemoryShmemChunk>
 ChildDiscardableSharedMemoryManager::AllocateLockedDiscardableMemory(
     size_t size) {
   base::AutoLock lock(lock_);
@@ skipping 64 matching lines @@
   size_t allocation_size_in_bytes = pages_to_allocate * base::GetPageSize();
 
   DiscardableSharedMemoryId new_id =
       g_next_discardable_shared_memory_id.GetNext();
 
   // Ask parent process to allocate a new discardable shared memory segment.
   scoped_ptr<base::DiscardableSharedMemory> shared_memory(
       AllocateLockedDiscardableSharedMemory(allocation_size_in_bytes, new_id));
 
   // Create span for allocated memory.
-  scoped_ptr<DiscardableSharedMemoryHeap::Span> new_span(
-      heap_.Grow(shared_memory.Pass(), allocation_size_in_bytes,
-                 base::Bind(&DeletedDiscardableSharedMemory, sender_, new_id)));
+  scoped_ptr<DiscardableSharedMemoryHeap::Span> new_span(heap_.Grow(
+      shared_memory.Pass(), allocation_size_in_bytes,
+      base::Bind(
+          &ChildDiscardableSharedMemoryManager::DeletedDiscardableSharedMemory,
+          weak_ptr_factory_.GetWeakPtr(), new_id)));
 
   // Unlock and insert any left over memory into free lists.
   if (pages < pages_to_allocate) {
     scoped_ptr<DiscardableSharedMemoryHeap::Span> leftover =
         heap_.Split(new_span.get(), pages);
     leftover->shared_memory()->Unlock(
         leftover->start() * base::GetPageSize() -
             reinterpret_cast<size_t>(leftover->shared_memory()->memory()),
         leftover->length() * base::GetPageSize());
     heap_.MergeIntoFreeLists(leftover.Pass());
@@ skipping 82 matching lines @@
   sender_->Send(
       new ChildProcessHostMsg_SyncAllocateLockedDiscardableSharedMemory(
           size, id, &handle));
   CHECK(base::SharedMemory::IsHandleValid(handle));
   scoped_ptr<base::DiscardableSharedMemory> memory(
       new base::DiscardableSharedMemory(handle));
   CHECK(memory->Map(size));
   return memory.Pass();
 }
 
+void ChildDiscardableSharedMemoryManager::DeletedDiscardableSharedMemory(
+    DiscardableSharedMemoryId id) {
+  sender_->Send(new ChildProcessHostMsg_DeletedDiscardableSharedMemory(id));
+}
+
 void ChildDiscardableSharedMemoryManager::MemoryUsageChanged(
     size_t new_bytes_total,
     size_t new_bytes_free) const {
   TRACE_COUNTER2("renderer", "DiscardableMemoryUsage", "allocated",
                  new_bytes_total - new_bytes_free, "free", new_bytes_free);
 
   static const char kDiscardableMemoryUsageKey[] = "dm-usage";
   base::debug::SetCrashKeyValue(kDiscardableMemoryUsageKey,
                                 base::Uint64ToString(new_bytes_total));
 
   static const char kDiscardableMemoryUsageFreeKey[] = "dm-usage-free";
   base::debug::SetCrashKeyValue(kDiscardableMemoryUsageFreeKey,
                                 base::Uint64ToString(new_bytes_free));
 }
 
 }  // namespace content