37 lines
953 B
C++
37 lines
953 B
C++
#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_; }
|
|
};
|