1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef INCLUDE_PERFETTO_TRACING_CORE_SHARED_MEMORY_H_ 18 #define INCLUDE_PERFETTO_TRACING_CORE_SHARED_MEMORY_H_ 19 20 #include <stddef.h> 21 22 #include <memory> 23 24 #include "perfetto/base/export.h" 25 26 namespace perfetto { 27 28 // An abstract interface that models the shared memory region shared between 29 // Service and Producer. The concrete implementation of this is up to the 30 // transport layer. This can be as simple as a malloc()-ed buffer, if both 31 // Producer and Service are hosted in the same process, or some posix shared 32 // memory for the out-of-process case (see src/unix_rpc). 33 // Both this class and the Factory are subclassed by the transport layer, which 34 // will attach platform specific fields to it (e.g., a unix file descriptor). 35 class PERFETTO_EXPORT SharedMemory { 36 public: 37 class Factory { 38 public: 39 virtual ~Factory(); 40 virtual std::unique_ptr<SharedMemory> CreateSharedMemory(size_t) = 0; 41 }; 42 43 // The transport layer is expected to tear down the resource associated to 44 // this object region when destroyed. 45 virtual ~SharedMemory(); 46 47 virtual void* start() const = 0; 48 virtual size_t size() const = 0; 49 }; 50 51 } // namespace perfetto 52 53 #endif // INCLUDE_PERFETTO_TRACING_CORE_SHARED_MEMORY_H_ 54
