blob: 4ec9722ee81bc4c39488279c626d95dc7eb06e71 [file] [log] [blame]
// Copyright 2016 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 <windows.h>
#include <memory>
#include "base/macros.h"
#include "base/strings/string16.h"
#include "base/synchronization/waitable_event.h"
#include "base/win/scoped_handle.h"
namespace base {
class CommandLine;
class TimeDelta;
namespace installer {
class InstallationState;
class InstallerState;
class MasterPreferences;
// Any modification to a Chrome installation should be done within the scope of
// a SetupSingleton. There can be only one active SetupSingleton per Chrome
// installation at a time.
class SetupSingleton {
// Returns a SetupSingleton which, throughout its lifetime, gives the current
// process the exclusive right to modify the Chrome installation described by
// |installer_state| (installation directory and associated registry keys).
// May block. |original_state| and |installer_state| are updated using
// |command_line| and |master_preferences| to reflect the new state of the
// installation after acquisition. Returns nullptr on failure.
static std::unique_ptr<SetupSingleton> Acquire(
const base::CommandLine& command_line,
const MasterPreferences& master_preferences,
InstallationState* original_state,
InstallerState* installer_state);
// Releases the exclusive right to modify the Chrome installation.
// Waits until |max_time| has passed or another process tries to acquire a
// SetupSingleton for the same Chrome installation. In the latter case, the
// method returns true and this SetupSingleton should be released as soon as
// possible to unblock the other process.
bool WaitForInterrupt(const base::TimeDelta& max_time) const;
class ScopedHoldMutex {
// Waits up to a certain amount of time to acquire |mutex|. Returns true on
// success. |mutex| will be released in the destructor.
bool Acquire(HANDLE mutex);
SetupSingleton(base::win::ScopedHandle setup_mutex,
base::win::ScopedHandle exit_event);
// A mutex that must be held to modify the Chrome installation directory.
base::win::ScopedHandle setup_mutex_;
// Holds |setup_mutex_| throughout the lifetime of this SetupSingleton.
ScopedHoldMutex scoped_hold_setup_mutex_;
// An event signaled to ask the owner of |setup_mutex_| to release it as soon
// as possible.
mutable base::WaitableEvent exit_event_;
} // namespace installer