1 /* 2 * Copyright (C) 2012 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 ART_RUNTIME_BARRIER_H_ 18 #define ART_RUNTIME_BARRIER_H_ 19 20 #include "base/mutex.h" 21 #include "locks.h" 22 #include "UniquePtr.h" 23 24 namespace art { 25 26 class Barrier { 27 public: 28 explicit Barrier(int count); 29 virtual ~Barrier(); 30 31 // Pass through the barrier, decrements the count but does not block. 32 void Pass(Thread* self); 33 34 // Wait on the barrier, decrement the count. 35 void Wait(Thread* self); 36 37 // Set the count to a new value, if the value is 0 then everyone waiting on the condition 38 // variable is resumed. 39 void Init(Thread* self, int count); 40 41 // Increment the count by delta, wait on condition if count is non zero. 42 void Increment(Thread* self, int delta); 43 44 private: 45 void SetCountLocked(Thread* self, int count) EXCLUSIVE_LOCKS_REQUIRED(lock_); 46 47 // Counter, when this reaches 0 all people blocked on the barrier are signalled. 48 int count_ GUARDED_BY(lock_); 49 50 Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 51 ConditionVariable condition_ GUARDED_BY(lock_); 52 }; 53 54 } // namespace art 55 #endif // ART_RUNTIME_BARRIER_H_ 56