L3 RRC/NAS developments

src/utils/light_sync.cpp

+//
+// This file is a part of UERANSIM open source project.
+// Copyright (c) 2021 ALİ GÜNGÖR.
+//
+// The software and all associated files are licensed under GPL-3.0
+// and subject to the terms and conditions defined in LICENSE file.
+//
+
+#include "light_sync.hpp"

src/utils/light_sync.hpp

+//
+// This file is a part of UERANSIM open source project.
+// Copyright (c) 2021 ALİ GÜNGÖR.
+//
+// The software and all associated files are licensed under GPL-3.0
+// and subject to the terms and conditions defined in LICENSE file.
+//
+
+#include "common.hpp"
+
+#include <atomic>
+#include <memory>
+#include <stdexcept>
+
+template <typename TInput, typename TOutput>
+class LightSync
+{
+    const int m_validForMs;
+    const int64_t m_validUntil;
+    const std::unique_ptr<TInput> m_input;
+    std::atomic_bool m_processed;
+    std::shared_ptr<TOutput> m_output;
+
+  public:
+    LightSync(int validForMs, std::unique_ptr<TInput> &&input)
+        : m_validForMs{validForMs}, m_validUntil{utils::CurrentTimeMillis() + static_cast<int64_t>(validForMs)},
+          m_input{std::move(input)}, m_processed{}, m_output{}
+    {
+        if (validForMs >= 2000)
+            throw std::runtime_error("LightSync timeout is too large");
+    }
+
+    const TInput &getInput()
+    {
+        return *m_input;
+    }
+
+    bool isValid()
+    {
+        return utils::CurrentTimeMillis() <= m_validUntil;
+    }
+
+    // Only producer can call at most once
+    void notifyProcessed(std::unique_ptr<TOutput> &&output)
+    {
+        if (m_processed)
+            throw std::runtime_error("LightSync processed more than once");
+        m_output = std::move(output);
+        m_processed = true;
+    }
+
+    // Only consumer can call at most once
+    std::shared_ptr<TOutput> waitForProcess()
+    {
+        while (true)
+        {
+            if (!isValid())
+                return nullptr;
+
+            if (m_processed)
+                return m_output;
+        }
+    }
+};
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