65 lines
2.1 KiB
C++
65 lines
2.1 KiB
C++
/*
|
|
* Copyright 2017 Discord, Inc.
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy of
|
|
* this software and associated documentation files (the "Software"), to deal in
|
|
* the Software without restriction, including without limitation the rights to
|
|
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
|
|
* of the Software, and to permit persons to whom the Software is furnished to do
|
|
* so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in all
|
|
* copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
* SOFTWARE.
|
|
*
|
|
*/
|
|
|
|
#ifndef DISCORD_MSG_QUEUE_H
|
|
#define DISCORD_MSG_QUEUE_H
|
|
|
|
#include <atomic>
|
|
|
|
// A simple queue. No locks, but only works with a single thread as producer and a single thread as
|
|
// a consumer. Mutex up as needed.
|
|
|
|
namespace discord_rpc {
|
|
|
|
template<typename ElementType, std::size_t QueueSize>
|
|
class MsgQueue {
|
|
ElementType queue_[QueueSize];
|
|
std::atomic_uint nextAdd_{ 0 };
|
|
std::atomic_uint nextSend_{ 0 };
|
|
std::atomic_uint pendingSends_{ 0 };
|
|
|
|
public:
|
|
MsgQueue() {}
|
|
|
|
ElementType *GetNextAddMessage() {
|
|
// if we are falling behind, bail
|
|
if (pendingSends_.load() >= QueueSize) {
|
|
return nullptr;
|
|
}
|
|
auto index = (nextAdd_++) % QueueSize;
|
|
return &queue_[index];
|
|
}
|
|
void CommitAdd() { ++pendingSends_; }
|
|
|
|
bool HavePendingSends() const { return pendingSends_.load() != 0; }
|
|
ElementType *GetNextSendMessage() {
|
|
auto index = (nextSend_++) % QueueSize;
|
|
return &queue_[index];
|
|
}
|
|
void CommitSend() { --pendingSends_; }
|
|
};
|
|
|
|
} // namespace discord_rpc
|
|
|
|
#endif // DISCORD_MSG_QUEUE_H
|