Keep only base/extractor.[cc|h].

base/single_instance.cc

-// Copyright 2003-2009 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-// ========================================================================
-//
-// Synchronization functions
-
-#include "omaha/base/single_instance.h"
-#include "omaha/base/constants.h"
-#include "omaha/base/debug.h"
-#include "omaha/base/logging.h"
-#include "omaha/base/scoped_any.h"
-#include "omaha/base/synchronized.h"
-#include "omaha/base/utils.h"
-
-namespace omaha {
-
-// Check to see whether an instance is already running across all sessions.
-// If not, enter single instance protection. The user must call Shutdown()
-// on that SingleInstance once single instance protection is no longer needed.
-bool SingleInstance::StartupSingleInstance(const TCHAR* id) {
-  ASSERT1(id);
-
-  bool already_running = false, already_running_in_different_session = false;
-  HRESULT hr = Startup(id,
-                       &already_running,
-                       &already_running_in_different_session);
-  ASSERT(SUCCEEDED(hr), (_T("")));
-
-  return already_running || already_running_in_different_session;
-}
-
-// Check to see whether an instance is already running in this session. If not,
-// enter session-only single instance protection. The user must call Shutdown()
-// on that SingleInstance once single instance protection is no longer needed.
-bool SingleInstance::StartupSingleSessionInstance(const TCHAR* id) {
-  ASSERT1(id);
-
-  bool already_running = false;
-  HRESULT hr = Startup(id, &already_running, NULL);
-  ASSERT(SUCCEEDED(hr), (_T("")));
-
-  return already_running;
-}
-
-// Startup a single instance protection. The user must call Shutdown() on
-// that SingleInstance once the single instance protection is no longer needed.
-//
-// Returns whether or not the process is already running
-// already_running means "already running in same session".
-// already_running_in_different_session means "already running on machine"
-HRESULT SingleInstance::Startup(const TCHAR* id,
-                                bool* already_running,
-                                bool* already_running_in_different_session) {
-  ASSERT1(id);
-  ASSERT1(already_running);
-
-  CString mutex_id;
-
-  // Use two mutexes: one to check for being the only instance in this
-  // session, and one for being the only instance in any terminal session.
-  // Only create (and check) the global mutex for one-per-machine check if
-  // the result is asked for.
-  // We don't actually obtain ownership of the mutex
-  // For information on the "Local" and "Global" namespace prefixes, see MSDN
-  // article "Kernel Object Namespaces".
-
-  // Create a user level mutex
-  CreateSyncId(id, SYNC_USER, &mutex_id);
-  RET_IF_FAILED(CreateInstanceMutex(mutex_id,
-                                    &user_mutex_handle_,
-                                    already_running));
-
-  // Create a global mutex
-  if (already_running_in_different_session) {
-    CreateSyncId(id, SYNC_GLOBAL, &mutex_id);
-    RET_IF_FAILED(CreateInstanceMutex(mutex_id,
-                                      &global_mutex_handle_,
-                                      already_running_in_different_session));
-  }
-
-  return S_OK;
-}
-
-// Create a mutex
-HRESULT SingleInstance::CreateInstanceMutex(const TCHAR* mutex_id,
-                                            HANDLE* mutex_handle,
-                                            bool* already_running) {
-  ASSERT1(mutex_id && *mutex_id);
-  ASSERT1(mutex_handle);
-  ASSERT1(already_running);
-
-  *already_running = false;
-
-  *mutex_handle = ::CreateMutex(NULL, false, mutex_id);
-  DWORD last_error = ::GetLastError();
-
-  // We check for both values because we sometimes see access
-  // denied.  We expect this to mean that the mutex was created by a
-  // different set of user credentials, which shouldn't happen under
-  // normal circumstances in our applications, but in fact we did
-  // see it happen.
-  if (last_error == ERROR_ALREADY_EXISTS || last_error == ERROR_ACCESS_DENIED) {
-    *already_running = true;
-    return S_OK;
-  }
-
-  if (*mutex_handle == NULL) {
-    HRESULT hr = HRESULT_FROM_WIN32(last_error);
-    ASSERT(false, (_T("[SingleInstance::CreateInstanceMutex]")
-                   _T("[failed to create mutex][%s][0x%x]"), mutex_id, hr));
-    return hr;
-  }
-
-  return S_OK;
-}
-
-// Shutdown a single instance protection
-HRESULT SingleInstance::Shutdown() {
-  if (user_mutex_handle_) {
-    VERIFY(::CloseHandle(user_mutex_handle_), (_T("")));
-    user_mutex_handle_ = NULL;
-  }
-
-  if (global_mutex_handle_) {
-    VERIFY(::CloseHandle(global_mutex_handle_), (_T("")));
-    global_mutex_handle_ = NULL;
-  }
-
-  return S_OK;
-}
-
-// Check to see whether an instance is already running
-HRESULT SingleInstance::CheckAlreadyRunning(
-    const TCHAR* id,
-    bool* already_running,
-    bool* already_running_in_different_session) {
-  ASSERT1(id);
-  ASSERT1(already_running);
-
-  CString mutex_id;
-
-  // Open a user level mutex
-  CreateSyncId(id, SYNC_USER, &mutex_id);
-  RET_IF_FAILED(OpenInstanceMutex(mutex_id, already_running));
-
-  // Open a global mutex
-  if (already_running_in_different_session) {
-    CreateSyncId(id, SYNC_GLOBAL, &mutex_id);
-    RET_IF_FAILED(OpenInstanceMutex(mutex_id,
-                                    already_running_in_different_session));
-  }
-
-  return S_OK;
-}
-
-// Open a mutex
-HRESULT SingleInstance::OpenInstanceMutex(const TCHAR* mutex_id,
-                                          bool* already_running) {
-  ASSERT1(mutex_id && *mutex_id);
-  ASSERT1(already_running);
-
-  *already_running = false;
-
-  scoped_handle mutex_handle(::OpenMutex(NULL, false, mutex_id));
-  DWORD last_error = ::GetLastError();
-
-  if (get(mutex_handle) || last_error == ERROR_ACCESS_DENIED) {
-    UTIL_LOG(L3, (_T("[SingleInstance::OpenInstanceMutex]")
-                  _T("[already running][0x%x]"), last_error));
-    *already_running = true;
-    return S_OK;
-  }
-
-  if (last_error != ERROR_FILE_NOT_FOUND) {
-    HRESULT hr = HRESULT_FROM_WIN32(last_error);
-    ASSERT(false, (_T("[SingleInstance::OpenInstanceMutex]")
-                   _T("[failed to open mutex][%s][0x%x]"), mutex_id, hr));
-    return hr;
-  }
-
-  return S_OK;
-}
-
-}  // namespace omaha
-