// 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 MOJO_CORE_BROKER_H_ #define MOJO_CORE_BROKER_H_ #include "base/memory/ref_counted.h" #include "base/memory/writable_shared_memory_region.h" #include "base/synchronization/lock.h" #include "mojo/public/cpp/platform/platform_channel_endpoint.h" #include "mojo/public/cpp/platform/platform_handle.h" namespace mojo { namespace core { // The Broker is a channel to the broker process, which allows synchronous IPCs // to fulfill shared memory allocation requests on some platforms. class Broker { public: // Note: If |wait_for_channel_handle| is |true|, this constructor blocks the // calling thread until it reads first message from |handle|, which must // contain another PlatformHandle for a NodeChannel. // // Otherwise, no initialization message is expected and this will not wait for // one. Broker(PlatformHandle handle, bool wait_for_channel_handle); Broker(const Broker&) = delete; Broker& operator=(const Broker&) = delete; ~Broker(); // Returns the platform handle that should be used to establish a NodeChannel // to the process which is inviting us to join its network. This is the first // handle read off the Broker channel upon construction. PlatformChannelEndpoint GetInviterEndpoint(); // Request a shared buffer from the broker process. Blocks the current thread. base::WritableSharedMemoryRegion GetWritableSharedMemoryRegion( size_t num_bytes); private: // Handle to the broker process, used for synchronous IPCs. PlatformHandle sync_channel_; // Channel endpoint connected to the inviter process. Received in the // first message over |sync_channel_|. PlatformChannelEndpoint inviter_endpoint_; // Lock to only allow one sync message at a time. This avoids having to deal // with message ordering since we can only have one request at a time // in-flight. base::Lock lock_; }; } // namespace core } // namespace mojo #endif // MOJO_CORE_BROKER_H_