| // 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. |
| |
| #ifndef CHROME_INSTALLER_SETUP_SETUP_SINGLETON_H_ |
| #define CHROME_INSTALLER_SETUP_SETUP_SINGLETON_H_ |
| |
| #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 { |
| public: |
| // 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. |
| ~SetupSingleton(); |
| |
| // 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; |
| |
| private: |
| class ScopedHoldMutex { |
| public: |
| ScopedHoldMutex(); |
| ~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); |
| |
| private: |
| HANDLE mutex_ = INVALID_HANDLE_VALUE; |
| |
| DISALLOW_COPY_AND_ASSIGN(ScopedHoldMutex); |
| }; |
| |
| 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_; |
| |
| DISALLOW_COPY_AND_ASSIGN(SetupSingleton); |
| }; |
| |
| } // namespace installer |
| |
| #endif // CHROME_INSTALLER_SETUP_SETUP_SINGLETON_H_ |