introduce sem_queue

2 files changed, 36 insertions, 0 deletions

diff --git a/src/utils/sem_queue.cpp b/src/utils/sem_queue.cpp
new file mode 100644
index 0000000..a3ca6e6
--- /dev/null
+++ b/src/utils/sem_queue.cpp
@@ -0,0 +1 @@
+#include "sem_queue.h"
diff --git a/src/utils/sem_queue.h b/src/utils/sem_queue.h
new file mode 100644
index 0000000..6987d88
--- /dev/null
+++ b/src/utils/sem_queue.h
@@ -0,0 +1,35 @@
+#pragma once
+
+#include <mutex>
+#include <queue>
+#include <semaphore>
+
+template<typename T, size_t S>
+class sem_queue
+{
+public:
+    inline void enqueue(const T &value)
+    {
+        m_free.acquire();
+        std::lock_guard l{m_mtx};
+        m_queue.push(value);
+        m_used.release();
+    }
+
+    inline T dequeue()
+    {
+        m_used.acquire();
+        std::lock_guard l{m_mtx};
+        const auto result = m_queue.front();
+        m_queue.pop();
+        m_free.release();
+
+        return result;
+    }
+
+private:
+    std::queue<T> m_queue;
+    std::mutex m_mtx;
+    std::counting_semaphore<S> m_free{S};
+    std::counting_semaphore<S> m_used{0};
+};