// Copyright 2014 The Android Open Source Project // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. #include "anbox/common/message_channel.h" namespace anbox { namespace common { MessageChannelBase::MessageChannelBase(size_t capacity) : pos_(0U), count_(0U), capacity_(capacity), lock_(), can_read_(), can_write_() {} MessageChannelBase::~MessageChannelBase() {} size_t MessageChannelBase::before_write() { std::unique_lock l(lock_, std::defer_lock); lock_.lock(); while (count_ >= capacity_) can_write_.wait(l); size_t result = pos_ + count_; if (result >= capacity_) result -= capacity_; return result; } void MessageChannelBase::after_write() { count_++; can_read_.notify_one(); lock_.unlock(); } size_t MessageChannelBase::before_read() { std::unique_lock l(lock_, std::defer_lock); lock_.lock(); while (count_ == 0) can_read_.wait(l); return pos_; } void MessageChannelBase::after_read() { if (++pos_ == capacity_) pos_ = 0U; count_--; can_write_.notify_one(); lock_.unlock(); } } // namespace common } // namespace anbox