| // Copyright 2016 The SwiftShader Authors. All Rights Reserved. |
| // |
| // 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 "Resource.hpp" |
| |
| #include "Memory.hpp" |
| #include "Debug.hpp" |
| |
| namespace sw |
| { |
| Resource::Resource(size_t bytes) : size(bytes) |
| { |
| buffer = allocate(bytes); |
| } |
| |
| Resource::~Resource() |
| { |
| deallocate(buffer); |
| } |
| |
| void *Resource::lock(Accessor claimer) |
| { |
| std::unique_lock<std::mutex> lock(mutex); |
| return acquire(lock, claimer); |
| } |
| |
| void *Resource::lock(Accessor relinquisher, Accessor claimer) |
| { |
| std::unique_lock<std::mutex> lock(mutex); |
| |
| // Release |
| if (count > 0 && accessor == relinquisher) |
| { |
| release(lock); |
| } |
| |
| // Acquire |
| acquire(lock, claimer); |
| |
| return buffer; |
| } |
| |
| void Resource::unlock() |
| { |
| std::unique_lock<std::mutex> lock(mutex); |
| release(lock); |
| } |
| |
| void *Resource::acquire(std::unique_lock<std::mutex> &lock, Accessor claimer) |
| { |
| while (count > 0 && accessor != claimer) |
| { |
| blocked++; |
| released.wait(lock, [&] { return count == 0 || accessor == claimer; }); |
| blocked--; |
| } |
| |
| accessor = claimer; |
| count++; |
| return buffer; |
| } |
| |
| void Resource::release(std::unique_lock<std::mutex> &lock) |
| { |
| ASSERT(count > 0); |
| |
| count--; |
| |
| if(count == 0) |
| { |
| if(orphaned) |
| { |
| lock.unlock(); |
| delete this; |
| return; |
| } |
| released.notify_one(); |
| } |
| } |
| |
| void Resource::destruct() |
| { |
| std::unique_lock<std::mutex> lock(mutex); |
| if(count == 0 && blocked == 0) |
| { |
| lock.unlock(); |
| delete this; |
| return; |
| } |
| orphaned = true; |
| } |
| |
| const void *Resource::data() const |
| { |
| return buffer; |
| } |
| } |