1 /* 2 * Copyright (c) 2021 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 #ifndef ECMASCRIPT_VM_THREAD_CONTROL_H 17 #define ECMASCRIPT_VM_THREAD_CONTROL_H 18 19 #include "libpandabase/utils/bit_field.h" 20 #include "os/mutex.h" 21 22 namespace panda::ecmascript { 23 class VmThreadControl { 24 public: 25 using VMNeedSuspensionBit = BitField<bool, 0, 1>; 26 using VMHasSuspendedBit = VMNeedSuspensionBit::NextFlag; 27 SetVMNeedSuspension(bool flag)28 void SetVMNeedSuspension(bool flag) 29 { 30 uint64_t newVal = VMNeedSuspensionBit::Update(threadStateBitField_, flag); 31 threadStateBitField_ = newVal; 32 } 33 VMNeedSuspension()34 bool VMNeedSuspension() 35 { 36 return VMNeedSuspensionBit::Decode(threadStateBitField_); 37 } 38 39 bool CheckSafepoint(); 40 41 void SuspendVM(); 42 43 void ResumeVM(); 44 45 bool NotifyVMThreadSuspension(); 46 SetVMSuspended(bool flag)47 void SetVMSuspended(bool flag) 48 { 49 uint64_t newVal = VMHasSuspendedBit::Update(threadStateBitField_, flag); 50 threadStateBitField_ = newVal; 51 } 52 IsSuspended()53 bool IsSuspended() 54 { 55 return VMHasSuspendedBit::Decode(threadStateBitField_); 56 } 57 58 private: 59 std::atomic<uint8_t> threadStateBitField_ {0}; 60 os::memory::Mutex vmThreadSuspensionMutex_; 61 os::memory::ConditionVariable vmThreadNeedSuspensionCV_; 62 os::memory::ConditionVariable vmThreadHasSuspendedCV_; 63 }; 64 } // namespace panda::ecmascript 65 #endif // ECMASCRIPT_VM_THREAD_CONTROL_H