| // Copyright (c) 2019 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 PLATFORM_IMPL_PLATFORM_CLIENT_POSIX_H_ |
| #define PLATFORM_IMPL_PLATFORM_CLIENT_POSIX_H_ |
| |
| #include <atomic> |
| #include <memory> |
| #include <mutex> |
| #include <thread> |
| |
| #include "absl/types/optional.h" |
| #include "platform/api/time.h" |
| #include "platform/base/macros.h" |
| #include "platform/impl/socket_handle_waiter_posix.h" |
| #include "platform/impl/task_runner.h" |
| #include "platform/impl/tls_data_router_posix.h" |
| #include "util/operation_loop.h" |
| |
| namespace openscreen { |
| |
| class UdpSocketReaderPosix; |
| |
| // Creates and provides access to singletons used by the default platform |
| // implementation. An instance must be created before an application uses any |
| // public modules in the Open Screen Library. |
| // |
| // ShutDown() should be called to destroy the PlatformClientPosix's singletons |
| // and TaskRunner to save resources when library APIs are not in use. |
| // ShutDown() calls TaskRunner::RunUntilStopped() to run any pending cleanup |
| // tasks. |
| // |
| // Create and ShutDown must be called in the same sequence. |
| // |
| // FIXME: Remove Create and Shutdown and use the ctor/dtor directly. |
| class PlatformClientPosix { |
| public: |
| // Initializes the platform implementation. |
| // |
| // |networking_loop_interval| sets the minimum amount of time that should pass |
| // between iterations of the loop used to handle networking operations. Higher |
| // values will result in less time being spent on these operations, but also |
| // potentially less performant networking operations. |
| // |
| // |networking_operation_timeout| sets how much time may be spent on a |
| // single networking operation type. |
| // |
| // |task_runner| is a client-provided TaskRunner implementation. |
| static void Create(Clock::duration networking_operation_timeout, |
| Clock::duration networking_loop_interval, |
| std::unique_ptr<TaskRunnerImpl> task_runner); |
| |
| // Initializes the platform implementation and creates a new TaskRunner (which |
| // starts a new thread). |
| static void Create(Clock::duration networking_operation_timeout, |
| Clock::duration networking_loop_interval); |
| |
| // Shuts down and deletes the PlatformClient instance currently stored as a |
| // singleton. This method is expected to be called before program exit. After |
| // calling this method, if the client wishes to continue using the platform |
| // library, Create() must be called again. |
| static void ShutDown(); |
| |
| static PlatformClientPosix* GetInstance() { return instance_; } |
| |
| // This method is thread-safe. |
| // FIXME: Rename to GetTlsDataRouter() |
| TlsDataRouterPosix* tls_data_router(); |
| |
| // This method is thread-safe. |
| // FIXME: Rename to GetUdpSocketReader() |
| UdpSocketReaderPosix* udp_socket_reader(); |
| |
| // Returns the TaskRunner associated with this PlatformClient. |
| // NOTE: This method is expected to be thread safe. |
| TaskRunner* GetTaskRunner(); |
| |
| protected: |
| // Called by ShutDown(). |
| ~PlatformClientPosix(); |
| |
| static void SetInstance(PlatformClientPosix* client); |
| |
| private: |
| PlatformClientPosix(Clock::duration networking_operation_timeout, |
| Clock::duration networking_loop_interval); |
| |
| PlatformClientPosix(Clock::duration networking_operation_timeout, |
| Clock::duration networking_loop_interval, |
| std::unique_ptr<TaskRunnerImpl> task_runner); |
| |
| // This method is thread-safe. |
| SocketHandleWaiterPosix* socket_handle_waiter(); |
| |
| // Helper functions to use when creating and calling the OperationLoop used |
| // for the networking thread. |
| void PerformSocketHandleWaiterActions(Clock::duration timeout); |
| void PerformTlsDataRouterActions(Clock::duration timeout); |
| std::vector<std::function<void(Clock::duration)>> networking_operations(); |
| |
| // Instance objects with threads are created at object-creation time. |
| // NOTE: Delayed instantiation of networking_loop_ may be useful in future. |
| OperationLoop networking_loop_; |
| |
| std::unique_ptr<TaskRunnerImpl> task_runner_; |
| |
| // Track whether the associated instance variable has been created yet. |
| std::atomic_bool waiter_created_{false}; |
| std::atomic_bool tls_data_router_created_{false}; |
| |
| // Flags used to ensure that initialization of below instance objects occurs |
| // only once across all threads. |
| std::once_flag waiter_initialization_; |
| std::once_flag udp_socket_reader_initialization_; |
| std::once_flag tls_data_router_initialization_; |
| |
| // Instance objects are created at runtime when they are first needed. |
| std::unique_ptr<SocketHandleWaiterPosix> waiter_; |
| std::unique_ptr<UdpSocketReaderPosix> udp_socket_reader_; |
| std::unique_ptr<TlsDataRouterPosix> tls_data_router_; |
| |
| // Threads for running TaskRunner and OperationLoop instances. |
| // NOTE: These must be declared last to avoid nondterministic failures. |
| std::thread networking_loop_thread_; |
| absl::optional<std::thread> task_runner_thread_; |
| |
| static PlatformClientPosix* instance_; |
| |
| OSP_DISALLOW_COPY_AND_ASSIGN(PlatformClientPosix); |
| }; |
| |
| } // namespace openscreen |
| |
| #endif // PLATFORM_IMPL_PLATFORM_CLIENT_POSIX_H_ |