AppCache: Ensure inflight ActiveCalls are not destroyed

content/browser/appcache/appcache_disk_cache.cc

 // 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.
 
 #include "content/browser/appcache/appcache_disk_cache.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
+#include "base/memory/ref_counted.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "net/base/cache_type.h"
 #include "net/base/net_errors.h"
 
 namespace content {
 
 // A callback shim that provides storage for the 'backend_ptr' value
 // and will delete a resulting ptr if completion occurs after its
@@ skipping 86 matching lines @@
     if (owner_)
       owner_->RemoveOpenEntry(this);
   }
 
   disk_cache::Entry* disk_cache_entry_;
   AppCacheDiskCache* owner_;
 };
 
 // Separate object to hold state for each Create, Delete, or Doom call
 // while the call is in-flight and to produce an EntryImpl upon completion.
-class AppCacheDiskCache::ActiveCall {
+class AppCacheDiskCache::ActiveCall
+    : public base::RefCounted<AppCacheDiskCache::ActiveCall> {
  public:
-  explicit ActiveCall(AppCacheDiskCache* owner)
-      : entry_(NULL),
-        owner_(owner),
-        entry_ptr_(NULL) {
+  static int CreateEntry(const base::WeakPtr<AppCacheDiskCache>& owner,
+                         int64 key, Entry** entry,
+                         const net::CompletionCallback& callback) {
+    scoped_refptr<ActiveCall> active_call(
+        new ActiveCall(owner, entry, callback));
+    int rv = owner->disk_cache()->CreateEntry(
+        base::Int64ToString(key), &active_call->entry_ptr_,
+        base::Bind(&ActiveCall::OnAsyncCompletion, active_call));
+    return active_call->HandleImmediateReturnValue(rv);
   }
 
-  int CreateEntry(int64 key, Entry** entry,
-                  const net::CompletionCallback& callback) {
-    int rv = owner_->disk_cache()->CreateEntry(
-        base::Int64ToString(key), &entry_ptr_,
-        base::Bind(&ActiveCall::OnAsyncCompletion, base::Unretained(this)));
-    return HandleImmediateReturnValue(rv, entry, callback);
+  static int OpenEntry(const base::WeakPtr<AppCacheDiskCache>& owner,
+                       int64 key, Entry** entry,
+                       const net::CompletionCallback& callback) {
+    scoped_refptr<ActiveCall> active_call(
+        new ActiveCall(owner, entry, callback));
+    int rv = owner->disk_cache()->OpenEntry(
+        base::Int64ToString(key), &active_call->entry_ptr_,
+        base::Bind(&ActiveCall::OnAsyncCompletion, active_call));
+    return active_call->HandleImmediateReturnValue(rv);
   }
 
-  int OpenEntry(int64 key, Entry** entry,
-                const net::CompletionCallback& callback) {
-    int rv = owner_->disk_cache()->OpenEntry(
-        base::Int64ToString(key), &entry_ptr_,
-        base::Bind(&ActiveCall::OnAsyncCompletion, base::Unretained(this)));
-    return HandleImmediateReturnValue(rv, entry, callback);
-  }
-
-  int DoomEntry(int64 key, const net::CompletionCallback& callback) {
-    int rv = owner_->disk_cache()->DoomEntry(
+  static int DoomEntry(const base::WeakPtr<AppCacheDiskCache>& owner,
+                       int64 key, const net::CompletionCallback& callback) {
+    scoped_refptr<ActiveCall> active_call(
+        new ActiveCall(owner, nullptr, callback));
+    int rv = owner->disk_cache()->DoomEntry(
         base::Int64ToString(key),
-        base::Bind(&ActiveCall::OnAsyncCompletion, base::Unretained(this)));
-    return HandleImmediateReturnValue(rv, NULL, callback);
+        base::Bind(&ActiveCall::OnAsyncCompletion, active_call));
+    return active_call->HandleImmediateReturnValue(rv);
   }
 
  private:
-  int HandleImmediateReturnValue(int rv, Entry** entry,
-                                 const net::CompletionCallback& callback) {
+  friend class base::RefCounted<AppCacheDiskCache::ActiveCall>;
+
+  ActiveCall(const base::WeakPtr<AppCacheDiskCache>& owner,
+             Entry** entry,
+             const net::CompletionCallback& callback)
+      : owner_(owner),
+        entry_(entry),
+        callback_(callback),
+        entry_ptr_(nullptr) {
+    DCHECK(owner_);
+  }
+
+  ~ActiveCall() {}
+
+  int HandleImmediateReturnValue(int rv) {
     if (rv == net::ERR_IO_PENDING) {
       // OnAsyncCompletion will be called later.
-      callback_ = callback;
-      entry_ = entry;
-      owner_->AddActiveCall(this);
-      return net::ERR_IO_PENDING;
+      return rv;
     }
-    if (rv == net::OK && entry)
-      *entry = new EntryImpl(entry_ptr_, owner_);
-    delete this;
+
+    if (rv == net::OK && entry_) {
+      DCHECK(entry_ptr_);
+      *entry_ = new EntryImpl(entry_ptr_, owner_.get());
+    }
     return rv;
   }
 
   void OnAsyncCompletion(int rv) {
-    owner_->RemoveActiveCall(this);
-    if (rv == net::OK && entry_)
-      *entry_ = new EntryImpl(entry_ptr_, owner_);
+    if (rv == net::OK && entry_) {
+      DCHECK(entry_ptr_);
+      if (owner_) {
+        *entry_ = new EntryImpl(entry_ptr_, owner_.get());
+      } else {
+        entry_ptr_->Close();
+        rv = net::ERR_ABORTED;
+      }
+    }
     callback_.Run(rv);
-    callback_.Reset();
-    delete this;
   }
 
+  base::WeakPtr<AppCacheDiskCache> owner_;
   Entry** entry_;
   net::CompletionCallback callback_;
-  AppCacheDiskCache* owner_;
   disk_cache::Entry* entry_ptr_;
 };
 
 AppCacheDiskCache::AppCacheDiskCache()
-    : is_disabled_(false) {
+    : is_disabled_(false),
+      weak_factory_(this) {
 }
 
 AppCacheDiskCache::~AppCacheDiskCache() {
   Disable();
 }
 
 int AppCacheDiskCache::InitWithDiskBackend(
     const base::FilePath& disk_cache_directory,
     int disk_cache_size,
     bool force,
@@ skipping 27 matching lines @@
 
   // We need to close open file handles in order to reinitalize the
   // appcache system on the fly. File handles held in both entries and in
   // the main disk_cache::Backend class need to be released.
   for (OpenEntries::const_iterator iter = open_entries_.begin();
        iter != open_entries_.end(); ++iter) {
     (*iter)->Abandon();
   }
   open_entries_.clear();
   disk_cache_.reset();
-  STLDeleteElements(&active_calls_);
 }
 
 int AppCacheDiskCache::CreateEntry(int64 key, Entry** entry,
                                    const net::CompletionCallback& callback) {
   DCHECK(entry);
   DCHECK(!callback.is_null());
   if (is_disabled_)
     return net::ERR_ABORTED;
 
   if (is_initializing()) {
     pending_calls_.push_back(PendingCall(CREATE, key, entry, callback));
     return net::ERR_IO_PENDING;
   }
 
   if (!disk_cache_)
     return net::ERR_FAILED;
 
-  return (new ActiveCall(this))->CreateEntry(key, entry, callback);
+  return ActiveCall::CreateEntry(
+      weak_factory_.GetWeakPtr(), key, entry, callback);
 }
 
 int AppCacheDiskCache::OpenEntry(int64 key, Entry** entry,
                                  const net::CompletionCallback& callback) {
   DCHECK(entry);
   DCHECK(!callback.is_null());
   if (is_disabled_)
     return net::ERR_ABORTED;
 
   if (is_initializing()) {
     pending_calls_.push_back(PendingCall(OPEN, key, entry, callback));
     return net::ERR_IO_PENDING;
   }
 
   if (!disk_cache_)
     return net::ERR_FAILED;
 
-  return (new ActiveCall(this))->OpenEntry(key, entry, callback);
+  return ActiveCall::OpenEntry(
+      weak_factory_.GetWeakPtr(), key, entry, callback);
 }
 
 int AppCacheDiskCache::DoomEntry(int64 key,
                                  const net::CompletionCallback& callback) {
   DCHECK(!callback.is_null());
   if (is_disabled_)
     return net::ERR_ABORTED;
 
   if (is_initializing()) {
     pending_calls_.push_back(PendingCall(DOOM, key, NULL, callback));
     return net::ERR_IO_PENDING;
   }
 
   if (!disk_cache_)
     return net::ERR_FAILED;
 
-  return (new ActiveCall(this))->DoomEntry(key, callback);
+  return ActiveCall::DoomEntry(weak_factory_.GetWeakPtr(), key, callback);
 }
 
 AppCacheDiskCache::PendingCall::PendingCall()
     : call_type(CREATE),
       key(0),
       entry(NULL) {
 }
 
 AppCacheDiskCache::PendingCall::PendingCall(PendingCallType call_type,
     int64 key,
@@ skipping 71 matching lines @@
         NOTREACHED();
         break;
     }
     if (rv != net::ERR_IO_PENDING)
       iter->callback.Run(rv);
   }
   pending_calls_.clear();
 }
 
 }  // namespace content