Make synchronous methods on disk_cache::SimpleEntryImpl() reentrant.

net/disk_cache/simple/simple_entry_impl.cc

 // Copyright (c) 2013 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 "net/disk_cache/simple/simple_entry_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/location.h"
@@ skipping 92 matching lines @@
   // Entry::Close() is expected to release this entry. See disk_cache.h for
   // details.
   delete this;
 }
 
 std::string SimpleEntryImpl::GetKey() const {
   return key_;
 }
 
 Time SimpleEntryImpl::GetLastUsed() const {
-  if (synchronous_entry_in_use_by_worker_) {
-    NOTIMPLEMENTED();
-    CHECK(false);
-  }
-  return synchronous_entry_->last_used();
+  return last_used_;
 }
 
 Time SimpleEntryImpl::GetLastModified() const {
-  if (synchronous_entry_in_use_by_worker_) {
-    NOTIMPLEMENTED();
-    CHECK(false);
-  }
-  return synchronous_entry_->last_modified();
+  return last_modified_;
 }
 
 int32 SimpleEntryImpl::GetDataSize(int index) const {
-  if (synchronous_entry_in_use_by_worker_) {
-    NOTIMPLEMENTED();
-    CHECK(false);
-  }
-  return synchronous_entry_->data_size(index);
+  return data_size_[index];
 }
 
 int SimpleEntryImpl::ReadData(int index,
                               int offset,
                               net::IOBuffer* buf,
                               int buf_len,
                               const CompletionCallback& callback) {
   // TODO(gavinp): Add support for overlapping reads. The net::HttpCache does
   // make overlapping read requests when multiple transactions access the same
   // entry as read only.
@@ skipping 76 matching lines @@
 
 int SimpleEntryImpl::ReadyForSparseIO(const CompletionCallback& callback) {
   // TODO(gavinp): Determine if the simple backend should support sparse data.
   NOTIMPLEMENTED();
   return net::ERR_FAILED;
 }
 
 SimpleEntryImpl::SimpleEntryImpl(
     SimpleSynchronousEntry* synchronous_entry)
     : ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)),
+      path_(synchronous_entry->path()),
       key_(synchronous_entry->key()),
       synchronous_entry_(synchronous_entry),
       synchronous_entry_in_use_by_worker_(false),
       has_been_doomed_(false) {
   DCHECK(synchronous_entry);
+  SetSynchronousData();
 }
 
 SimpleEntryImpl::~SimpleEntryImpl() {
   DCHECK(!synchronous_entry_);
 }
 
 // static
 void SimpleEntryImpl::CreationOperationComplete(
     const CompletionCallback& completion_callback,
     Entry** out_entry,
     SimpleSynchronousEntry* sync_entry) {
   if (!sync_entry) {
     completion_callback.Run(net::ERR_FAILED);
     return;
   }
   *out_entry = new SimpleEntryImpl(sync_entry);
   completion_callback.Run(net::OK);
 }
 
 // static
 void SimpleEntryImpl::EntryOperationComplete(
     const CompletionCallback& completion_callback,
     base::WeakPtr<SimpleEntryImpl> entry,
     int result) {
   if (entry) {
     DCHECK(entry->synchronous_entry_in_use_by_worker_);
     entry->synchronous_entry_in_use_by_worker_ = false;
+    entry->SetSynchronousData();
   }
   completion_callback.Run(result);
 }
 
+void SimpleEntryImpl::SetSynchronousData() {
+  DCHECK(!synchronous_entry_in_use_by_worker_);
+
+  // TODO(felipeg): These copies to avoid data races are not optimal. While
+  // adding an IO thread index (for fast misses etc...), we can store this data
+  // in that structure. This also solves problems with last_used() on ext4
+  // filesystems not being accurate.
+
+  last_used_ = synchronous_entry_->last_used();
+  last_modified_ = synchronous_entry_->last_modified();
+  for (int i = 0; i < kSimpleEntryFileCount; ++i)
+    data_size_[i] = synchronous_entry_->data_size(i);
+}
+
 }  // namespace disk_cache