1 /* 2 * Copyright (C) 2024 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 SRC_BIGTRACE_ORCHESTRATOR_RESIZABLE_TASK_POOL_H_ 18 #define SRC_BIGTRACE_ORCHESTRATOR_RESIZABLE_TASK_POOL_H_ 19 20 #include <functional> 21 #include <mutex> 22 #include <thread> 23 24 #include <grpcpp/client_context.h> 25 26 namespace perfetto::bigtrace { 27 28 // This struct maps a thread to a context in order to allow for the cancellation 29 // of the thread's current gRPC call through ClientContext's TryCancel 30 struct ThreadWithContext { ThreadWithContextThreadWithContext31 explicit ThreadWithContext(std::function<void(ThreadWithContext*)> fn) 32 : thread(fn, this) {} 33 34 // Cancels the gRPC call through ClientContext as well as signalling a stop to 35 // the thread CancelThreadWithContext36 void Cancel() { 37 client_context->TryCancel(); 38 std::lock_guard<std::mutex> lk(mutex); 39 is_thread_cancelled = true; 40 } 41 42 // Returns whether the thread has been cancelled IsCancelledThreadWithContext43 bool IsCancelled() { 44 std::lock_guard<std::mutex> lk(mutex); 45 return is_thread_cancelled; 46 } 47 48 std::mutex mutex; 49 std::unique_ptr<grpc::ClientContext> client_context; 50 std::thread thread; 51 bool is_thread_cancelled = false; 52 }; 53 54 // This pool manages a set of running tasks for a given query, and provides the 55 // ability to resize in order to fairly distribute an equal number of workers 56 // for each user through preemption 57 class ResizableTaskPool { 58 public: 59 explicit ResizableTaskPool(std::function<void(ThreadWithContext*)> fn); 60 void Resize(uint32_t new_size); 61 void JoinAll(); 62 63 private: 64 std::function<void(ThreadWithContext*)> fn_; 65 std::vector<std::unique_ptr<ThreadWithContext>> contextual_threads_; 66 }; 67 } // namespace perfetto::bigtrace 68 69 #endif // SRC_BIGTRACE_ORCHESTRATOR_RESIZABLE_TASK_POOL_H_ 70