Disk cache: Remove all non essential synchronization from the cache destructor.

net/disk_cache/entry_impl.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
 #ifndef NET_DISK_CACHE_ENTRY_IMPL_H_
 #define NET_DISK_CACHE_ENTRY_IMPL_H_
 #pragma once
 
 #include "base/memory/scoped_ptr.h"
 #include "net/base/net_log.h"
 #include "net/disk_cache/disk_cache.h"
 #include "net/disk_cache/storage_block.h"
 #include "net/disk_cache/storage_block-inl.h"
 
 namespace disk_cache {
 
 class BackendImpl;
+class InFlightBackendIO;
 class SparseControl;
 
 // This class implements the Entry interface. An object of this
 // class represents a single entry on the cache.
 class NET_EXPORT_PRIVATE EntryImpl
     : public Entry,
       public base::RefCounted<EntryImpl> {
   friend class base::RefCounted<EntryImpl>;
   friend class SparseControl;
  public:
   enum Operation {
     kRead,
     kWrite,
     kSparseRead,
     kSparseWrite,
     kAsyncIO,
     kReadAsync1,
     kWriteAsync1
   };
 
   EntryImpl(BackendImpl* backend, Addr address, bool read_only);
 
   // Background implementation of the Entry interface.
   void DoomImpl();
-  int ReadDataImpl(int index, int offset, net::IOBuffer* buf, int buf_len,
-                   const net::CompletionCallback& callback);
-  int WriteDataImpl(int index, int offset, net::IOBuffer* buf, int buf_len,
-                    const net::CompletionCallback& callback, bool truncate);
-  int ReadSparseDataImpl(int64 offset, net::IOBuffer* buf, int buf_len,
-                         const net::CompletionCallback& callback);
-  int WriteSparseDataImpl(int64 offset, net::IOBuffer* buf, int buf_len,
-                          const net::CompletionCallback& callback);
+  int ReadDataImpl(int index, int offset, IOBuffer* buf, int buf_len,
+                   const CompletionCallback& callback);
+  int WriteDataImpl(int index, int offset, IOBuffer* buf, int buf_len,
+                    const CompletionCallback& callback, bool truncate);
+  int ReadSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len,
+                         const CompletionCallback& callback);
+  int WriteSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len,
+                          const CompletionCallback& callback);
   int GetAvailableRangeImpl(int64 offset, int len, int64* start);
   void CancelSparseIOImpl();
-  int ReadyForSparseIOImpl(const net::CompletionCallback& callback);
+  int ReadyForSparseIOImpl(const CompletionCallback& callback);
 
   inline CacheEntryBlock* entry() {
     return &entry_;
   }
 
   inline CacheRankingsBlock* rankings() {
     return &node_;
   }
 
   uint32 GetHash();
@@ skipping 51 matching lines @@
   bool SanityCheck();
   bool DataSanityCheck();
 
   // Attempts to make this entry reachable though the key.
   void FixForDelete();
 
   // Handle the pending asynchronous IO count.
   void IncrementIoCount();
   void DecrementIoCount();
 
+  // This entry is being returned to the user. It is always called from the
+  // primary thread (not the dedicated cache thread).
+  void OnEntryCreated(BackendImpl* backend);
+
   // Set the access times for this entry. This method provides support for
   // the upgrade tool.
   void SetTimes(base::Time last_used, base::Time last_modified);
 
   // Generates a histogram for the time spent working on this operation.
   void ReportIOTime(Operation op, const base::TimeTicks& start);
 
   // Logs a begin event and enables logging for the EntryImpl.  Will also cause
   // an end event to be logged on destruction.  The EntryImpl must have its key
   // initialized before this is called.  |created| is true if the Entry was
   // created rather than opened.
   void BeginLogging(net::NetLog* net_log, bool created);
 
   const net::BoundNetLog& net_log() const;
 
   // Returns the number of blocks needed to store an EntryStore.
   static int NumBlocksForEntry(int key_size);
 
   // Entry interface.
   virtual void Doom() OVERRIDE;
   virtual void Close() OVERRIDE;
   virtual std::string GetKey() const OVERRIDE;
   virtual base::Time GetLastUsed() const OVERRIDE;
   virtual base::Time GetLastModified() const OVERRIDE;
   virtual int32 GetDataSize(int index) const OVERRIDE;
-  virtual int ReadData(
-      int index, int offset, net::IOBuffer* buf, int buf_len,
-      const net::CompletionCallback& callback) OVERRIDE;
-  virtual int WriteData(int index, int offset, net::IOBuffer* buf, int buf_len,
-                        const net::CompletionCallback& callback,
+  virtual int ReadData(int index, int offset, IOBuffer* buf, int buf_len,
+                       const CompletionCallback& callback) OVERRIDE;
+  virtual int WriteData(int index, int offset, IOBuffer* buf, int buf_len,
+                        const CompletionCallback& callback,
                         bool truncate) OVERRIDE;
-  virtual int ReadSparseData(
-      int64 offset, net::IOBuffer* buf, int buf_len,
-      const net::CompletionCallback& callback) OVERRIDE;
-  virtual int WriteSparseData(
-      int64 offset, net::IOBuffer* buf, int buf_len,
-      const net::CompletionCallback& callback) OVERRIDE;
-  virtual int GetAvailableRange(
-      int64 offset, int len, int64* start,
-      const net::CompletionCallback& callback) OVERRIDE;
+  virtual int ReadSparseData(int64 offset, IOBuffer* buf, int buf_len,
+                             const CompletionCallback& callback) OVERRIDE;
+  virtual int WriteSparseData(int64 offset, IOBuffer* buf, int buf_len,
+                              const CompletionCallback& callback) OVERRIDE;
+  virtual int GetAvailableRange(int64 offset, int len, int64* start,
+                                const CompletionCallback& callback) OVERRIDE;
   virtual bool CouldBeSparse() const OVERRIDE;
   virtual void CancelSparseIO() OVERRIDE;
-  virtual int ReadyForSparseIO(
-      const net::CompletionCallback& callback) OVERRIDE;
+  virtual int ReadyForSparseIO(const CompletionCallback& callback) OVERRIDE;
 
  private:
   enum {
      kNumStreams = 3
   };
   class UserBuffer;
 
   virtual ~EntryImpl();
 
   // Do all the work for ReadDataImpl and WriteDataImpl.  Implemented as
   // separate functions to make logging of results simpler.
-  int InternalReadData(int index, int offset, net::IOBuffer* buf,
-                       int buf_len, const net::CompletionCallback& callback);
-  int InternalWriteData(int index, int offset, net::IOBuffer* buf, int buf_len,
-                        const net::CompletionCallback& callback, bool truncate);
+  int InternalReadData(int index, int offset, IOBuffer* buf,
+                       int buf_len, const CompletionCallback& callback);
+  int InternalWriteData(int index, int offset, IOBuffer* buf, int buf_len,
+                        const CompletionCallback& callback, bool truncate);
 
   // Initializes the storage for an internal or external data block.
   bool CreateDataBlock(int index, int size);
 
   // Initializes the storage for an internal or external generic block.
   bool CreateBlock(int size, Addr* address);
 
   // Deletes the data pointed by address, maybe backed by files_[index].
   // Note that most likely the caller should delete (and store) the reference to
   // |address| *before* calling this method because we don't want to have an
@@ skipping 54 matching lines @@
   // responsible for deleting the block (or file) from the backing store at some
   // point; there is no need to report any storage-size change, only to do the
   // actual cleanup.
   void GetData(int index, char** buffer, Addr* address);
 
   // Logs this entry to the internal trace buffer.
   void Log(const char* msg);
 
   CacheEntryBlock entry_;     // Key related information for this entry.
   CacheRankingsBlock node_;   // Rankings related information for this entry.
-  BackendImpl* backend_;      // Back pointer to the cache.
+  base::WeakPtr<BackendImpl> backend_;  // Back pointer to the cache.
+  base::WeakPtr<InFlightBackendIO> background_queue_;  // In-progress queue.
   scoped_ptr<UserBuffer> user_buffers_[kNumStreams];  // Stores user data.
   // Files to store external user data and key.
   scoped_refptr<File> files_[kNumStreams + 1];
   mutable std::string key_;           // Copy of the key.
   int unreported_size_[kNumStreams];  // Bytes not reported yet to the backend.
   bool doomed_;               // True if this entry was removed from the cache.
   bool read_only_;            // True if not yet writing.
   bool dirty_;                // True if we detected that this is a dirty entry.
   scoped_ptr<SparseControl> sparse_;  // Support for sparse entries.
 
   net::BoundNetLog net_log_;
 
   DISALLOW_COPY_AND_ASSIGN(EntryImpl);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_ENTRY_IMPL_H_