chrome/browser/importer/firefox_profile_lock.h

   1 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_IMPORTER_FIREFOX_PROFILE_LOCK_H__
   6 #define CHROME_BROWSER_IMPORTER_FIREFOX_PROFILE_LOCK_H__
   7
   8 #include "build/build_config.h"
   9
  10 #if defined(OS_WIN)
  11 #include <windows.h>
  12 #endif
  13
  14 #include "base/basictypes.h"
  15 #include "base/files/file_path.h"
  16 #include "base/gtest_prod_util.h"
  17
  18 // Firefox is designed to allow only one application to access its
  19 // profile at the same time.
  20 // Reference:
  21 //   http://kb.mozillazine.org/Profile_in_use
  22 //
  23 // This class is based on Firefox code in:
  24 //   profile/dirserviceprovider/src/nsProfileLock.cpp
  25 // The license block is:
  26
  27 /* ***** BEGIN LICENSE BLOCK *****
  28 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  29 *
  30 * The contents of this file are subject to the Mozilla Public License Version
  31 * 1.1 (the "License"); you may not use this file except in compliance with
  32 * the License. You may obtain a copy of the License at
  33 * http://www.mozilla.org/MPL/
  34 *
  35 * Software distributed under the License is distributed on an "AS IS" basis,
  36 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  37 * for the specific language governing rights and limitations under the
  38 * License.
  39 *
  40 * The Original Code is mozilla.org code.
  41 *
  42 * The Initial Developer of the Original Code is
  43 * Netscape Communications Corporation.
  44 * Portions created by the Initial Developer are Copyright (C) 2002
  45 * the Initial Developer. All Rights Reserved.
  46 *
  47 * Contributor(s):
  48 *   Conrad Carlen <ccarlen@netscape.com>
  49 *   Brendan Eich <brendan@mozilla.org>
  50 *   Colin Blake <colin@theblakes.com>
  51 *   Javier Pedemonte <pedemont@us.ibm.com>
  52 *   Mats Palmgren <mats.palmgren@bredband.net>
  53 *
  54 * Alternatively, the contents of this file may be used under the terms of
  55 * either the GNU General Public License Version 2 or later (the "GPL"), or
  56 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  57 * in which case the provisions of the GPL or the LGPL are applicable instead
  58 * of those above. If you wish to allow use of your version of this file only
  59 * under the terms of either the GPL or the LGPL, and not to allow others to
  60 * use your version of this file under the terms of the MPL, indicate your
  61 * decision by deleting the provisions above and replace them with the notice
  62 * and other provisions required by the GPL or the LGPL. If you do not delete
  63 * the provisions above, a recipient may use your version of this file under
  64 * the terms of any one of the MPL, the GPL or the LGPL.
  65 *
  66 * ***** END LICENSE BLOCK ***** */
  67
  68 class FirefoxProfileLock {
  69  public:
  70   explicit FirefoxProfileLock(const base::FilePath& path);
  71   ~FirefoxProfileLock();
  72
  73   // Locks and releases the profile.
  74   void Lock();
  75   void Unlock();
  76
  77   // Returns true if we lock the profile successfully.
  78   bool HasAcquired();
  79
  80  private:
  81   FRIEND_TEST_ALL_PREFIXES(FirefoxProfileLockTest, ProfileLock);
  82   FRIEND_TEST_ALL_PREFIXES(FirefoxProfileLockTest, ProfileLockOrphaned);
  83
  84   static const base::FilePath::CharType* kLockFileName;
  85   static const base::FilePath::CharType* kOldLockFileName;
  86
  87   void Init();
  88
  89   // Full path of the lock file in the profile folder.
  90   base::FilePath lock_file_;
  91
  92   // The handle of the lock file.
  93 #if defined(OS_WIN)
  94   HANDLE lock_handle_;
  95 #elif defined(OS_POSIX)
  96   int lock_fd_;
  97
  98   // On Posix systems Firefox apparently first tries to put a fcntl lock
  99   // on a file and if that fails, it does a regular exculsive open on another
 100   // file. This variable contains the location of this other file.
 101   base::FilePath old_lock_file_;
 102
 103   // Method that tries to put a fcntl lock on file specified by |lock_file_|.
 104   // Returns false if lock is already held by another process. true in all
 105   // other cases.
 106   bool LockWithFcntl();
 107 #endif
 108
 109   DISALLOW_COPY_AND_ASSIGN(FirefoxProfileLock);
 110 };
 111
 112 #endif  // CHROME_BROWSER_IMPORTER_FIREFOX_PROFILE_LOCK_H__