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#pragma once
#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.
template <typename ElementType, 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_; }
};
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