1 /* 2 * Copyright (C) 2020 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 _UI_INPUT_INPUTDISPATCHER_ANRTRACKER_H 18 #define _UI_INPUT_INPUTDISPATCHER_ANRTRACKER_H 19 20 #include <binder/IBinder.h> 21 #include <utils/Timers.h> 22 #include <set> 23 24 namespace android::inputdispatcher { 25 26 /** 27 * Keeps track of the times when each connection is going to ANR. 28 * Provides the ability to quickly find the connection that is going to cause ANR next. 29 */ 30 class AnrTracker { 31 public: 32 void insert(nsecs_t timeoutTime, sp<IBinder> token); 33 void erase(nsecs_t timeoutTime, const sp<IBinder>& token); 34 void eraseToken(const sp<IBinder>& token); 35 void clear(); 36 37 bool empty() const; 38 // If empty() is false, return the time at which the next connection should cause an ANR 39 // If empty() is true, return LONG_LONG_MAX 40 nsecs_t firstTimeout() const; 41 // Return the token of the next connection that should cause an ANR. 42 // Do not call this unless empty() is false, you will encounter undefined behaviour. 43 const sp<IBinder>& firstToken() const; 44 45 private: 46 // Optimization: use a multiset to keep track of the event timeouts. When an event is sent 47 // to the InputConsumer, we add an entry to this structure. We look at the smallest value to 48 // determine if any of the connections is unresponsive, and to determine when we should wake 49 // next for the future ANR check. 50 // Using a multiset helps quickly look up the next timeout due. 51 // 52 // We must use a multi-set, because it is plausible (although highly unlikely) to have entries 53 // from the same connection and same timestamp, but different sequence numbers. 54 // We are not tracking sequence numbers, and just allow duplicates to exist. 55 std::multiset<std::pair<nsecs_t /*timeoutTime*/, sp<IBinder> /*connectionToken*/>> mAnrTimeouts; 56 }; 57 58 } // namespace android::inputdispatcher 59 60 #endif // _UI_INPUT_INPUTDISPATCHER_ANRTRACKER_H 61