blob: 623aa7f42f7fa58e7de77cc2f816b7b33ddf4484 [file] [log] [blame]
// 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 "chrome/browser/process_singleton.h"
#include <shellapi.h>
#include "base/base_paths.h"
#include "base/bind.h"
#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/process/process.h"
#include "base/process/process_info.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "base/time/time.h"
#include "base/win/metro.h"
#include "base/win/registry.h"
#include "base/win/scoped_handle.h"
#include "base/win/windows_version.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/browser_process_platform_part.h"
#include "chrome/browser/chrome_process_finder_win.h"
#include "chrome/browser/metro_utils/metro_chrome_win.h"
#include "chrome/browser/shell_integration.h"
#include "chrome/browser/ui/simple_message_box.h"
#include "chrome/common/chrome_constants.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_paths_internal.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/grit/chromium_strings.h"
#include "chrome/installer/util/wmi.h"
#include "content/public/common/result_codes.h"
#include "net/base/escape.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/gfx/win/hwnd_util.h"
namespace {
const char kLockfile[] = "lockfile";
const int kMetroChromeActivationTimeoutMs = 3000;
// A helper class that acquires the given |mutex| while the AutoLockMutex is in
// scope.
class AutoLockMutex {
explicit AutoLockMutex(HANDLE mutex) : mutex_(mutex) {
DWORD result = ::WaitForSingleObject(mutex_, INFINITE);
DPCHECK(result == WAIT_OBJECT_0) << "Result = " << result;
~AutoLockMutex() {
BOOL released = ::ReleaseMutex(mutex_);
HANDLE mutex_;
// A helper class that releases the given |mutex| while the AutoUnlockMutex is
// in scope and immediately re-acquires it when going out of scope.
class AutoUnlockMutex {
explicit AutoUnlockMutex(HANDLE mutex) : mutex_(mutex) {
BOOL released = ::ReleaseMutex(mutex_);
~AutoUnlockMutex() {
DWORD result = ::WaitForSingleObject(mutex_, INFINITE);
DPCHECK(result == WAIT_OBJECT_0) << "Result = " << result;
HANDLE mutex_;
// Checks the visibility of the enumerated window and signals once a visible
// window has been found.
BOOL CALLBACK BrowserWindowEnumeration(HWND window, LPARAM param) {
bool* result = reinterpret_cast<bool*>(param);
*result = ::IsWindowVisible(window) != 0;
// Stops enumeration if a visible window has been found.
return !*result;
bool ParseCommandLine(const COPYDATASTRUCT* cds,
base::CommandLine* parsed_command_line,
base::FilePath* current_directory) {
// We should have enough room for the shortest command (min_message_size)
// and also be a multiple of wchar_t bytes. The shortest command
// possible is L"START\0\0" (empty current directory and command line).
static const int min_message_size = 7;
if (cds->cbData < min_message_size * sizeof(wchar_t) ||
cds->cbData % sizeof(wchar_t) != 0) {
LOG(WARNING) << "Invalid WM_COPYDATA, length = " << cds->cbData;
return false;
// We split the string into 4 parts on NULLs.
const std::wstring msg(static_cast<wchar_t*>(cds->lpData),
cds->cbData / sizeof(wchar_t));
const std::wstring::size_type first_null = msg.find_first_of(L'\0');
if (first_null == 0 || first_null == std::wstring::npos) {
// no NULL byte, don't know what to do
LOG(WARNING) << "Invalid WM_COPYDATA, length = " << msg.length() <<
", first null = " << first_null;
return false;
// Decode the command, which is everything until the first NULL.
if (msg.substr(0, first_null) == L"START") {
// Another instance is starting parse the command line & do what it would
// have done.
VLOG(1) << "Handling STARTUP request from another process";
const std::wstring::size_type second_null =
msg.find_first_of(L'\0', first_null + 1);
if (second_null == std::wstring::npos ||
first_null == msg.length() - 1 || second_null == msg.length()) {
LOG(WARNING) << "Invalid format for start command, we need a string in 4 "
"parts separated by NULLs";
return false;
// Get current directory.
*current_directory = base::FilePath(msg.substr(first_null + 1,
second_null - first_null));
const std::wstring::size_type third_null =
msg.find_first_of(L'\0', second_null + 1);
if (third_null == std::wstring::npos ||
third_null == msg.length()) {
LOG(WARNING) << "Invalid format for start command, we need a string in 4 "
"parts separated by NULLs";
// Get command line.
const std::wstring cmd_line =
msg.substr(second_null + 1, third_null - second_null);
*parsed_command_line = base::CommandLine::FromString(cmd_line);
return true;
return false;
bool ProcessLaunchNotification(
const ProcessSingleton::NotificationCallback& notification_callback,
UINT message,
WPARAM wparam,
LPARAM lparam,
LRESULT* result) {
if (message != WM_COPYDATA)
return false;
// Handle the WM_COPYDATA message from another process.
const COPYDATASTRUCT* cds = reinterpret_cast<COPYDATASTRUCT*>(lparam);
base::CommandLine parsed_command_line(base::CommandLine::NO_PROGRAM);
base::FilePath current_directory;
if (!ParseCommandLine(cds, &parsed_command_line, &current_directory)) {
*result = TRUE;
return true;
*result = notification_callback.Run(parsed_command_line, current_directory) ?
return true;
// Returns true if Chrome needs to be relaunched into Windows 8 immersive mode.
// Following conditions apply:-
// 1. Windows 8 or greater.
// 2. Not in Windows 8 immersive mode.
// 3. Chrome is default browser.
// 4. Process integrity level is not high.
// 5. The profile data directory is the default directory.
// 6. Last used mode was immersive/machine is a tablet.
// TODO(ananta)
// Move this function to a common place as the Windows 8 delegate_execute
// handler can possibly use this.
bool ShouldLaunchInWindows8ImmersiveMode(const base::FilePath& user_data_dir) {
// Returning false from this function doesn't mean we don't launch immersive
// mode in Aura. This function is specifically called in case when we need
// to relaunch desktop launched chrome into immersive mode through 'relaunch'
// menu. In case of Aura, we will use delegate_execute to do the relaunch.
return false;
bool DisplayShouldKillMessageBox() {
return chrome::ShowMessageBox(
NULL, l10n_util::GetStringUTF16(IDS_PRODUCT_NAME),
} // namespace
// Microsoft's Softricity virtualization breaks the sandbox processes.
// So, if we detect the Softricity DLL we use WMI Win32_Process.Create to
// break out of the virtualization environment.
bool ProcessSingleton::EscapeVirtualization(
const base::FilePath& user_data_dir) {
if (::GetModuleHandle(L"sftldr_wow64.dll") ||
::GetModuleHandle(L"sftldr.dll")) {
int process_id;
if (!installer::WMIProcess::Launch(::GetCommandLineW(), &process_id))
return false;
is_virtualized_ = true;
// The new window was spawned from WMI, and won't be in the foreground.
// So, first we sleep while the new chrome.exe instance starts (because
// WaitForInputIdle doesn't work here). Then we poll for up to two more
// seconds and make the window foreground if we find it (or we give up).
HWND hwnd = 0;
for (int tries = 200; tries; --tries) {
hwnd = chrome::FindRunningChromeWindow(user_data_dir);
if (hwnd) {
return true;
return false;
const base::FilePath& user_data_dir,
const NotificationCallback& notification_callback)
: notification_callback_(notification_callback),
base::Bind(&DisplayShouldKillMessageBox)) {
ProcessSingleton::~ProcessSingleton() {
if (lock_file_ != INVALID_HANDLE_VALUE)
// Code roughly based on Mozilla.
ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcess() {
if (is_virtualized_)
return PROCESS_NOTIFIED; // We already spawned the process in this case.
if (lock_file_ == INVALID_HANDLE_VALUE && !remote_window_) {
return LOCK_ERROR;
} else if (!remote_window_) {
switch (chrome::AttemptToNotifyRunningChrome(remote_window_, false)) {
case chrome::NOTIFY_SUCCESS:
case chrome::NOTIFY_FAILED:
remote_window_ = NULL;
case chrome::NOTIFY_WINDOW_HUNG:
// Fall through and potentially terminate the hung browser.
DWORD process_id = 0;
DWORD thread_id = ::GetWindowThreadProcessId(remote_window_, &process_id);
if (!thread_id || !process_id) {
remote_window_ = NULL;
base::Process process = base::Process::Open(process_id);
// The window is hung. Scan for every window to find a visible one.
bool visible_window = false;
// If there is a visible browser window, ask the user before killing it.
if (visible_window && !should_kill_remote_process_callback_.Run()) {
// The user denied. Quit silently.
// Time to take action. Kill the browser process.
process.Terminate(content::RESULT_CODE_HUNG, true);
remote_window_ = NULL;
ProcessSingleton::NotifyOtherProcessOrCreate() {
ProcessSingleton::NotifyResult result = PROCESS_NONE;
if (!Create()) {
result = NotifyOtherProcess();
if (result == PROCESS_NONE)
result = PROFILE_IN_USE;
} else {
return result;
// Look for a Chrome instance that uses the same profile directory. If there
// isn't one, create a message window with its title set to the profile
// directory path.
bool ProcessSingleton::Create() {
static const wchar_t kMutexName[] = L"Local\\ChromeProcessSingletonStartup!";
static const wchar_t kMetroActivationEventName[] =
remote_window_ = chrome::FindRunningChromeWindow(user_data_dir_);
if (!remote_window_ && !EscapeVirtualization(user_data_dir_)) {
// Make sure we will be the one and only process creating the window.
// We use a named Mutex since we are protecting against multi-process
// access. As documented, it's clearer to NOT request ownership on creation
// since it isn't guaranteed we will get it. It is better to create it
// without ownership and explicitly get the ownership afterward.
base::win::ScopedHandle only_me(::CreateMutex(NULL, FALSE, kMutexName));
if (!only_me.IsValid()) {
DPLOG(FATAL) << "CreateMutex failed";
return false;
AutoLockMutex auto_lock_only_me(only_me.Get());
// We now own the mutex so we are the only process that can create the
// window at this time, but we must still check if someone created it
// between the time where we looked for it above and the time the mutex
// was given to us.
remote_window_ = chrome::FindRunningChromeWindow(user_data_dir_);
// In Win8+, a new Chrome process launched in Desktop mode may need to be
// transmuted into Metro Chrome (see ShouldLaunchInWindows8ImmersiveMode for
// heuristics). To accomplish this, the current Chrome activates Metro
// Chrome, releases the startup mutex, and waits for metro Chrome to take
// the singleton. From that point onward, the command line for this Chrome
// process will be sent to Metro Chrome by the usual channels.
if (!remote_window_ && base::win::GetVersion() >= base::win::VERSION_WIN8 &&
!base::win::IsMetroProcess()) {
// |metro_activation_event| is created right before activating a Metro
// Chrome (note that there can only be one Metro Chrome process; by OS
// design); all following Desktop processes will then wait for this event
// to be signaled by Metro Chrome which will do so as soon as it grabs
// this singleton (should any of the waiting processes timeout waiting for
// the signal they will try to grab the singleton for themselves which
// will result in a forced Desktop Chrome launch in the worst case).
base::win::ScopedHandle metro_activation_event(
::OpenEvent(SYNCHRONIZE, FALSE, kMetroActivationEventName));
if (!metro_activation_event.IsValid() &&
ShouldLaunchInWindows8ImmersiveMode(user_data_dir_)) {
// No Metro activation is under way, but the desire is to launch in
// Metro mode: activate and rendez-vous with the activated process.
::CreateEvent(NULL, TRUE, FALSE, kMetroActivationEventName));
if (!chrome::ActivateMetroChrome()) {
// Failed to launch immersive Chrome, default to launching on Desktop.
LOG(ERROR) << "Failed to launch immersive chrome";
if (metro_activation_event.IsValid()) {
// Release |only_me| (to let Metro Chrome grab this singleton) and wait
// until the event is signaled (i.e. Metro Chrome was successfully
// activated). Ignore timeout waiting for |metro_activation_event|.
AutoUnlockMutex auto_unlock_only_me(only_me.Get());
DWORD result = ::WaitForSingleObject(metro_activation_event.Get(),
DPCHECK(result == WAIT_OBJECT_0 || result == WAIT_TIMEOUT)
<< "Result = " << result;
// Check if this singleton was successfully grabbed by another process
// (hopefully Metro Chrome). Failing to do so, this process will grab
// the singleton and launch in Desktop mode.
remote_window_ = chrome::FindRunningChromeWindow(user_data_dir_);
if (!remote_window_) {
// We have to make sure there is no Chrome instance running on another
// machine that uses the same profile.
base::FilePath lock_file_path = user_data_dir_.AppendASCII(kLockfile);
lock_file_ = ::CreateFile(lock_file_path.value().c_str(),
DWORD error = ::GetLastError();
error == ERROR_ALREADY_EXISTS) << "Lock file exists but is writable.";
<< "Lock file can not be created! Error code: " << error;
if (lock_file_ != INVALID_HANDLE_VALUE) {
// Set the window's title to the path of our user data directory so
// other Chrome instances can decide if they should forward to us.
bool result = window_.CreateNamed(
base::Bind(&ProcessLaunchNotification, notification_callback_),
CHECK(result && window_.hwnd());
if (base::win::GetVersion() >= base::win::VERSION_WIN8) {
// Make sure no one is still waiting on Metro activation whether it
// succeeded (i.e., this is the Metro process) or failed.
base::win::ScopedHandle metro_activation_event(
::OpenEvent(EVENT_MODIFY_STATE, FALSE, kMetroActivationEventName));
if (metro_activation_event.IsValid())
return window_.hwnd() != NULL;
void ProcessSingleton::Cleanup() {
void ProcessSingleton::OverrideShouldKillRemoteProcessCallbackForTesting(
const ShouldKillRemoteProcessCallback& display_dialog_callback) {
should_kill_remote_process_callback_ = display_dialog_callback;