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- // 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 COMPONENTS_KEEP_ALIVE_REGISTRY_KEEP_ALIVE_REGISTRY_H_
- #define COMPONENTS_KEEP_ALIVE_REGISTRY_KEEP_ALIVE_REGISTRY_H_
- #include <unordered_map>
- #include <vector>
- #include "base/memory/singleton.h"
- #include "base/observer_list.h"
- enum class KeepAliveOrigin;
- enum class KeepAliveRestartOption;
- class KeepAliveStateObserver;
- // Centralized registry that objects in the browser can use to
- // express their requirements wrt the lifetime of the browser.
- // Observers registered with it can then react as those requirements
- // change.
- // In particular, this is how the browser process knows when to stop
- // or stay alive.
- // Note: BrowserProcessImpl registers to react on changes.
- // TestingBrowserProcess does not do it, meaning that the shutdown
- // sequence does not happen during unit tests.
- class KeepAliveRegistry {
- public:
- static KeepAliveRegistry* GetInstance();
- KeepAliveRegistry(const KeepAliveRegistry&) = delete;
- KeepAliveRegistry& operator=(const KeepAliveRegistry&) = delete;
- // Methods to query the state of the registry.
- bool IsKeepingAlive() const;
- bool IsKeepingAliveOnlyByBrowserOrigin() const;
- bool IsRestartAllowed() const;
- bool IsOriginRegistered(KeepAliveOrigin origin) const;
- void AddObserver(KeepAliveStateObserver* observer);
- void RemoveObserver(KeepAliveStateObserver* observer);
- // Returns whether restart would be allowed if all the keep alives for the
- // provided |origins| were not registered.
- bool WouldRestartWithout(const std::vector<KeepAliveOrigin>& origins) const;
- // True if shutdown is in progress. No new KeepAlive should be registered
- // while shutting down.
- bool IsShuttingDown() const;
- // Call when shutting down to ensure registering a new KeepAlive CHECKs.
- void SetIsShuttingDown(bool value = true);
- // True if restarting is in progress.
- bool IsRestarting() const;
- // Called when restarting is triggered.
- void SetRestarting();
- private:
- friend struct base::DefaultSingletonTraits<KeepAliveRegistry>;
- // Friend to be able to use Register/Unregister
- friend class ScopedKeepAlive;
- friend std::ostream& operator<<(std::ostream& out,
- const KeepAliveRegistry& registry);
- // TODO(dgn): Remove this when std::hash supports enums directly (c++14)
- // http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2148
- struct EnumClassHash {
- std::size_t operator()(KeepAliveOrigin origin) const {
- return static_cast<int>(origin);
- }
- };
- using OriginMap = std::unordered_map<KeepAliveOrigin, int, EnumClassHash>;
- KeepAliveRegistry();
- ~KeepAliveRegistry();
- // Add/Remove entries. Do not use directly, use ScopedKeepAlive instead.
- void Register(KeepAliveOrigin origin, KeepAliveRestartOption restart);
- void Unregister(KeepAliveOrigin origin, KeepAliveRestartOption restart);
- // Methods called when a specific aspect of the state of the registry changes.
- void OnKeepAliveStateChanged(bool new_keeping_alive);
- void OnRestartAllowedChanged(bool new_restart_allowed);
- // Unregisters one occurrence of the provided |origin| from |keep_alive_map|
- void DecrementCount(KeepAliveOrigin origin, OriginMap* keep_alive_map);
- // Tracks the registered KeepAlives, storing the origin and the number of
- // registered KeepAlives for each.
- OriginMap registered_keep_alives_;
- // Tracks the registered KeepAlives that had KeepAliveRestartOption::ENABLED
- // set, storing the origin and the number of restart allowed KeepAlives for
- // each origin.
- OriginMap restart_allowed_keep_alives_;
- // Total number of registered KeepAlives
- int registered_count_;
- // Number of registered keep alives that have KeepAliveRestartOption::ENABLED.
- int restart_allowed_count_;
- // Used to guard against registering during shutdown.
- bool is_shutting_down_ = false;
- // Used to handle KeepAliveRestartOption::ENABLED.
- bool is_restarting_ = false;
- base::ObserverList<KeepAliveStateObserver>::Unchecked observers_;
- };
- #endif // COMPONENTS_KEEP_ALIVE_REGISTRY_KEEP_ALIVE_REGISTRY_H_
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