// 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.
#ifndef CHROME_BROWSER_PROCESS_SINGLETON_H_
#define CHROME_BROWSER_PROCESS_SINGLETON_H_
#include "build/build_config.h"
#if defined(OS_WIN)
#include <windows.h>
#endif // defined(OS_WIN)
#include <set>
#include <vector>
#include "base/basictypes.h"
#include "base/callback.h"
#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/memory/ref_counted.h"
#include "base/process/process.h"
#include "base/threading/non_thread_safe.h"
#include "ui/gfx/native_widget_types.h"
#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
#include "base/files/scoped_temp_dir.h"
#endif
#if defined(OS_WIN)
#include "base/win/message_window.h"
#endif // defined(OS_WIN)
namespace base {
class CommandLine;
}
// ProcessSingleton ----------------------------------------------------------
//
// This class allows different browser processes to communicate with
// each other. It is named according to the user data directory, so
// we can be sure that no more than one copy of the application can be
// running at once with a given data directory.
//
// Implementation notes:
// - the Windows implementation uses an invisible global message window;
// - the Linux implementation uses a Unix domain socket in the user data dir.
class ProcessSingleton : public base::NonThreadSafe {
public:
enum NotifyResult {
PROCESS_NONE,
PROCESS_NOTIFIED,
PROFILE_IN_USE,
LOCK_ERROR,
};
// Implement this callback to handle notifications from other processes. The
// callback will receive the command line and directory with which the other
// Chrome process was launched. Return true if the command line will be
// handled within the current browser instance or false if the remote process
// should handle it (i.e., because the current process is shutting down).
typedef base::Callback<bool(
const base::CommandLine& command_line,
const base::FilePath& current_directory)> NotificationCallback;
ProcessSingleton(const base::FilePath& user_data_dir,
const NotificationCallback& notification_callback);
~ProcessSingleton();
// Notify another process, if available. Otherwise sets ourselves as the
// singleton instance. Returns PROCESS_NONE if we became the singleton
// instance. Callers are guaranteed to either have notified an existing
// process or have grabbed the singleton (unless the profile is locked by an
// unreachable process).
// TODO(brettw): Make the implementation of this method non-platform-specific
// by making Linux re-use the Windows implementation.
NotifyResult NotifyOtherProcessOrCreate();
// Sets ourself up as the singleton instance. Returns true on success. If
// false is returned, we are not the singleton instance and the caller must
// exit.
// NOTE: Most callers should generally prefer NotifyOtherProcessOrCreate() to
// this method, only callers for whom failure is prefered to notifying another
// process should call this directly.
bool Create();
// Clear any lock state during shutdown.
void Cleanup();
#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
static void DisablePromptForTesting();
#endif
protected:
// Notify another process, if available.
// Returns true if another process was found and notified, false if we should
// continue with the current process.
// On Windows, Create() has to be called before this.
NotifyResult NotifyOtherProcess();
#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
// Exposed for testing. We use a timeout on Linux, and in tests we want
// this timeout to be short.
NotifyResult NotifyOtherProcessWithTimeout(
const base::CommandLine& command_line,
int timeout_seconds,
bool kill_unresponsive);
NotifyResult NotifyOtherProcessWithTimeoutOrCreate(
const base::CommandLine& command_line,
int timeout_seconds);
void OverrideCurrentPidForTesting(base::ProcessId pid);
void OverrideKillCallbackForTesting(
const base::Callback<void(int)>& callback);
#endif
private:
#if !defined(OS_MACOSX)
// Timeout for the current browser process to respond. 20 seconds should be
// enough. It's only used in Windows and Linux implementations.
static const int kTimeoutInSeconds = 20;
#endif
NotificationCallback notification_callback_; // Handler for notifications.
#if defined(OS_WIN)
bool EscapeVirtualization(const base::FilePath& user_data_dir);
HWND remote_window_; // The HWND_MESSAGE of another browser.
base::win::MessageWindow window_; // The message-only window.
bool is_virtualized_; // Stuck inside Microsoft Softricity VM environment.
HANDLE lock_file_;
base::FilePath user_data_dir_;
#elif defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
// Return true if the given pid is one of our child processes.
// Assumes that the current pid is the root of all pids of the current
// instance.
bool IsSameChromeInstance(pid_t pid);
// Extract the process's pid from a symbol link path and if it is on
// the same host, kill the process, unlink the lock file and return true.
// If the process is part of the same chrome instance, unlink the lock file
// and return true without killing it.
// If the process is on a different host, return false.
bool KillProcessByLockPath();
// Default function to kill a process, overridable by tests.
void KillProcess(int pid);
// Allow overriding for tests.
base::ProcessId current_pid_;
// Function to call when the other process is hung and needs to be killed.
// Allows overriding for tests.
base::Callback<void(int)> kill_callback_;
// Path in file system to the socket.
base::FilePath socket_path_;
// Path in file system to the lock.
base::FilePath lock_path_;
// Path in file system to the cookie file.
base::FilePath cookie_path_;
// Temporary directory to hold the socket.
base::ScopedTempDir socket_dir_;
// Helper class for linux specific messages. LinuxWatcher is ref counted
// because it posts messages between threads.
class LinuxWatcher;
scoped_refptr<LinuxWatcher> watcher_;
#elif defined(OS_MACOSX)
// Path in file system to the lock.
base::FilePath lock_path_;
// File descriptor associated with the lockfile, valid between
// |Create()| and |Cleanup()|. Two instances cannot have a lock on
// the same file at the same time.
int lock_fd_;
#endif
DISALLOW_COPY_AND_ASSIGN(ProcessSingleton);
};
#endif // CHROME_BROWSER_PROCESS_SINGLETON_H_