process_singleton_win.cc revision 4a5e2dc747d50c653511c68ccb2cfbfb740bd5a7 
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#include "chrome/browser/process_singleton.h"
6
7#include "app/l10n_util.h"
8#include "app/win_util.h"
9#include "base/base_paths.h"
10#include "base/command_line.h"
11#include "base/file_path.h"
12#include "base/path_service.h"
13#include "base/process_util.h"
14#include "base/scoped_handle.h"
15#include "base/win_util.h"
16#include "chrome/browser/browser_process.h"
17#include "chrome/browser/extensions/extensions_startup.h"
18#include "chrome/browser/platform_util.h"
19#include "chrome/browser/profile.h"
20#include "chrome/browser/profile_manager.h"
21#include "chrome/browser/ui/browser_init.h"
22#include "chrome/common/chrome_constants.h"
23#include "chrome/common/chrome_paths.h"
24#include "chrome/common/chrome_switches.h"
25#include "chrome/common/result_codes.h"
26#include "chrome/installer/util/browser_distribution.h"
27#include "grit/chromium_strings.h"
28#include "grit/generated_resources.h"
29
30namespace {
31
32// Checks the visibility of the enumerated window and signals once a visible
33// window has been found.
34BOOL CALLBACK BrowserWindowEnumeration(HWND window, LPARAM param) {
35  bool* result = reinterpret_cast<bool*>(param);
36  *result = IsWindowVisible(window) != 0;
37  // Stops enumeration if a visible window has been found.
38  return !*result;
39}
40
41}  // namespace
42
43// Look for a Chrome instance that uses the same profile directory.
44ProcessSingleton::ProcessSingleton(const FilePath& user_data_dir)
45    : window_(NULL), locked_(false), foreground_window_(NULL) {
46  std::wstring user_data_dir_str(user_data_dir.ToWStringHack());
47  remote_window_ = FindWindowEx(HWND_MESSAGE, NULL,
48                                chrome::kMessageWindowClass,
49                                user_data_dir_str.c_str());
50  if (!remote_window_) {
51    // Make sure we will be the one and only process creating the window.
52    // We use a named Mutex since we are protecting against multi-process
53    // access. As documented, it's clearer to NOT request ownership on creation
54    // since it isn't guaranteed we will get it. It is better to create it
55    // without ownership and explicitly get the ownership afterward.
56    std::wstring mutex_name(L"Local\\ProcessSingletonStartup!");
57    mutex_name += BrowserDistribution::GetDistribution()->GetAppGuid();
58    ScopedHandle only_me(CreateMutex(NULL, FALSE, mutex_name.c_str()));
59    DCHECK(only_me.Get() != NULL) << "GetLastError = " << GetLastError();
60
61    // This is how we acquire the mutex (as opposed to the initial ownership).
62    DWORD result = WaitForSingleObject(only_me, INFINITE);
63    DCHECK(result == WAIT_OBJECT_0) << "Result = " << result <<
64        "GetLastError = " << GetLastError();
65
66    // We now own the mutex so we are the only process that can create the
67    // window at this time, but we must still check if someone created it
68    // between the time where we looked for it above and the time the mutex
69    // was given to us.
70    remote_window_ = FindWindowEx(HWND_MESSAGE, NULL,
71                                  chrome::kMessageWindowClass,
72                                  user_data_dir_str.c_str());
73    if (!remote_window_)
74      Create();
75    BOOL success = ReleaseMutex(only_me);
76    DCHECK(success) << "GetLastError = " << GetLastError();
77  }
78}
79
80ProcessSingleton::~ProcessSingleton() {
81  if (window_) {
82    DestroyWindow(window_);
83    UnregisterClass(chrome::kMessageWindowClass, GetModuleHandle(NULL));
84  }
85}
86
87ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcess() {
88  if (!remote_window_)
89    return PROCESS_NONE;
90
91  // Found another window, send our command line to it
92  // format is "START\0<<<current directory>>>\0<<<commandline>>>".
93  std::wstring to_send(L"START\0", 6);  // want the NULL in the string.
94  std::wstring cur_dir;
95  if (!PathService::Get(base::DIR_CURRENT, &cur_dir))
96    return PROCESS_NONE;
97  to_send.append(cur_dir);
98  to_send.append(L"\0", 1);  // Null separator.
99  to_send.append(GetCommandLineW());
100  to_send.append(L"\0", 1);  // Null separator.
101
102  // Allow the current running browser window making itself the foreground
103  // window (otherwise it will just flash in the taskbar).
104  DWORD process_id = 0;
105  DWORD thread_id = GetWindowThreadProcessId(remote_window_, &process_id);
106  // It is possible that the process owning this window may have died by now.
107  if (!thread_id || !process_id) {
108    remote_window_ = NULL;
109    return PROCESS_NONE;
110  }
111
112  AllowSetForegroundWindow(process_id);
113
114  COPYDATASTRUCT cds;
115  cds.dwData = 0;
116  cds.cbData = static_cast<DWORD>((to_send.length() + 1) * sizeof(wchar_t));
117  cds.lpData = const_cast<wchar_t*>(to_send.c_str());
118  DWORD_PTR result = 0;
119  if (SendMessageTimeout(remote_window_,
120                         WM_COPYDATA,
121                         NULL,
122                         reinterpret_cast<LPARAM>(&cds),
123                         SMTO_ABORTIFHUNG,
124                         kTimeoutInSeconds * 1000,
125                         &result)) {
126    // It is possible that the process owning this window may have died by now.
127    if (!result) {
128      remote_window_ = NULL;
129      return PROCESS_NONE;
130    }
131    return PROCESS_NOTIFIED;
132  }
133
134  // It is possible that the process owning this window may have died by now.
135  if (!IsWindow(remote_window_)) {
136    remote_window_ = NULL;
137    return PROCESS_NONE;
138  }
139
140  // The window is hung. Scan for every window to find a visible one.
141  bool visible_window = false;
142  EnumThreadWindows(thread_id,
143                    &BrowserWindowEnumeration,
144                    reinterpret_cast<LPARAM>(&visible_window));
145
146  // If there is a visible browser window, ask the user before killing it.
147  if (visible_window) {
148    std::wstring text = l10n_util::GetString(IDS_BROWSER_HUNGBROWSER_MESSAGE);
149    std::wstring caption = l10n_util::GetString(IDS_PRODUCT_NAME);
150    if (!platform_util::SimpleYesNoBox(NULL, caption, text)) {
151      // The user denied. Quit silently.
152      return PROCESS_NOTIFIED;
153    }
154  }
155
156  // Time to take action. Kill the browser process.
157  base::KillProcessById(process_id, ResultCodes::HUNG, true);
158  remote_window_ = NULL;
159  return PROCESS_NONE;
160}
161
162ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessOrCreate() {
163  NotifyResult result = NotifyOtherProcess();
164  if (result != PROCESS_NONE)
165    return result;
166  return Create() ? PROCESS_NONE : PROFILE_IN_USE;
167}
168
169// For windows, there is no need to call Create() since the call is made in
170// the constructor but to avoid having more platform specific code in
171// browser_main.cc we tolerate a second call which will do nothing.
172bool ProcessSingleton::Create() {
173  DCHECK(!remote_window_);
174  if (window_)
175    return true;
176
177  HINSTANCE hinst = GetModuleHandle(NULL);
178
179  WNDCLASSEX wc = {0};
180  wc.cbSize = sizeof(wc);
181  wc.lpfnWndProc = ProcessSingleton::WndProcStatic;
182  wc.hInstance = hinst;
183  wc.lpszClassName = chrome::kMessageWindowClass;
184  ATOM clazz = RegisterClassEx(&wc);
185  DCHECK(clazz);
186
187  FilePath user_data_dir;
188  PathService::Get(chrome::DIR_USER_DATA, &user_data_dir);
189
190  // Set the window's title to the path of our user data directory so other
191  // Chrome instances can decide if they should forward to us or not.
192  window_ = CreateWindow(chrome::kMessageWindowClass,
193                         user_data_dir.value().c_str(),
194                         0, 0, 0, 0, 0, HWND_MESSAGE, 0, hinst, 0);
195  DCHECK(window_);
196
197  win_util::SetWindowUserData(window_, this);
198  return true;
199}
200
201void ProcessSingleton::Cleanup() {
202}
203
204LRESULT ProcessSingleton::OnCopyData(HWND hwnd, const COPYDATASTRUCT* cds) {
205  // If locked, it means we are not ready to process this message because
206  // we are probably in a first run critical phase.
207  if (locked_) {
208    // Attempt to place ourselves in the foreground / flash the task bar.
209    if (IsWindow(foreground_window_))
210      SetForegroundWindow(foreground_window_);
211    return TRUE;
212  }
213
214  // Ignore the request if the browser process is already in shutdown path.
215  if (!g_browser_process || g_browser_process->IsShuttingDown()) {
216    LOG(WARNING) << "Not handling WM_COPYDATA as browser is shutting down";
217    return FALSE;
218  }
219
220  // We should have enough room for the shortest command (min_message_size)
221  // and also be a multiple of wchar_t bytes. The shortest command
222  // possible is L"START\0\0" (empty current directory and command line).
223  static const int min_message_size = 7;
224  if (cds->cbData < min_message_size * sizeof(wchar_t) ||
225      cds->cbData % sizeof(wchar_t) != 0) {
226    LOG(WARNING) << "Invalid WM_COPYDATA, length = " << cds->cbData;
227    return TRUE;
228  }
229
230  // We split the string into 4 parts on NULLs.
231  DCHECK(cds->lpData);
232  const std::wstring msg(static_cast<wchar_t*>(cds->lpData),
233                         cds->cbData / sizeof(wchar_t));
234  const std::wstring::size_type first_null = msg.find_first_of(L'\0');
235  if (first_null == 0 || first_null == std::wstring::npos) {
236    // no NULL byte, don't know what to do
237    LOG(WARNING) << "Invalid WM_COPYDATA, length = " << msg.length() <<
238      ", first null = " << first_null;
239    return TRUE;
240  }
241
242  // Decode the command, which is everything until the first NULL.
243  if (msg.substr(0, first_null) == L"START") {
244    // Another instance is starting parse the command line & do what it would
245    // have done.
246    VLOG(1) << "Handling STARTUP request from another process";
247    const std::wstring::size_type second_null =
248      msg.find_first_of(L'\0', first_null + 1);
249    if (second_null == std::wstring::npos ||
250        first_null == msg.length() - 1 || second_null == msg.length()) {
251      LOG(WARNING) << "Invalid format for start command, we need a string in 4 "
252        "parts separated by NULLs";
253      return TRUE;
254    }
255
256    // Get current directory.
257    const FilePath cur_dir(msg.substr(first_null + 1,
258                                      second_null - first_null));
259
260    const std::wstring::size_type third_null =
261        msg.find_first_of(L'\0', second_null + 1);
262    if (third_null == std::wstring::npos ||
263        third_null == msg.length()) {
264      LOG(WARNING) << "Invalid format for start command, we need a string in 4 "
265        "parts separated by NULLs";
266    }
267
268    // Get command line.
269    const std::wstring cmd_line =
270      msg.substr(second_null + 1, third_null - second_null);
271
272    CommandLine parsed_command_line = CommandLine::FromString(cmd_line);
273    PrefService* prefs = g_browser_process->local_state();
274    DCHECK(prefs);
275
276    Profile* profile = ProfileManager::GetDefaultProfile();
277    if (!profile) {
278      // We should only be able to get here if the profile already exists and
279      // has been created.
280      NOTREACHED();
281      return TRUE;
282    }
283
284    // Handle the --uninstall-extension startup action. This needs to done here
285    // in the process that is running with the target profile, otherwise the
286    // uninstall will fail to unload and remove all components.
287    if (parsed_command_line.HasSwitch(switches::kUninstallExtension)) {
288      extensions_startup::HandleUninstallExtension(parsed_command_line,
289                                                   profile);
290      return TRUE;
291    }
292
293    // Run the browser startup sequence again, with the command line of the
294    // signalling process.
295    BrowserInit::ProcessCommandLine(parsed_command_line, cur_dir, false,
296                                    profile, NULL);
297    return TRUE;
298  }
299  return TRUE;
300}
301
302LRESULT CALLBACK ProcessSingleton::WndProc(HWND hwnd, UINT message,
303                                           WPARAM wparam, LPARAM lparam) {
304  switch (message) {
305    case WM_COPYDATA:
306      return OnCopyData(reinterpret_cast<HWND>(wparam),
307                        reinterpret_cast<COPYDATASTRUCT*>(lparam));
308    default:
309      break;
310  }
311
312  return ::DefWindowProc(hwnd, message, wparam, lparam);
313}
314