1 // Copyright 2016 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MOJO_EDK_SYSTEM_BROKER_H_ 6 #define MOJO_EDK_SYSTEM_BROKER_H_ 7 8 #include "base/macros.h" 9 #include "base/memory/ref_counted.h" 10 #include "base/synchronization/lock.h" 11 #include "mojo/edk/embedder/scoped_platform_handle.h" 12 13 namespace mojo { 14 namespace edk { 15 16 class PlatformSharedBuffer; 17 18 // The Broker is a channel to the parent process, which allows synchronous IPCs. 19 class Broker { 20 public: 21 // Note: This is blocking, and will wait for the first message over 22 // |platform_handle|. 23 explicit Broker(ScopedPlatformHandle platform_handle); 24 ~Broker(); 25 26 // Returns the platform handle that should be used to establish a NodeChannel 27 // to the parent process. 28 ScopedPlatformHandle GetParentPlatformHandle(); 29 30 // Request a shared buffer from the parent process. Blocks the current thread. 31 scoped_refptr<PlatformSharedBuffer> GetSharedBuffer(size_t num_bytes); 32 33 private: 34 // Handle to the parent process, used for synchronous IPCs. 35 ScopedPlatformHandle sync_channel_; 36 37 // Handle to the parent process which is recieved in the first first message 38 // over |sync_channel_|. 39 ScopedPlatformHandle parent_channel_; 40 41 // Lock to only allow one sync message at a time. This avoids having to deal 42 // with message ordering since we can only have one request at a time 43 // in-flight. 44 base::Lock lock_; 45 46 DISALLOW_COPY_AND_ASSIGN(Broker); 47 }; 48 49 } // namespace edk 50 } // namespace mojo 51 52 #endif // MOJO_EDK_SYSTEM_BROKER_H_ 53
