chore: import upstream snapshot with attribution

kt-kernel/cpu_backend/shared_mem_buffer.h

@@ -0,0 +1,63 @@
+/**
+ * @Description  :
+ * @Author       : chenht2022
+ * @Date         : 2024-08-05 04:49:08
+ * @Version      : 1.0.0
+ * @LastEditors  : chenht2022
+ * @LastEditTime : 2024-08-05 06:36:41
+ * @Copyright (c) 2024 by KVCache.AI, All Rights Reserved.
+ **/
+
+#ifndef CPUINFER_SHAREDMEMBUFFER_H
+#define CPUINFER_SHAREDMEMBUFFER_H
+
+#include <cstdint>
+#include <cstdlib>
+#include <functional>
+#include <map>
+#include <memory>
+#include <mutex>
+#include <variant>
+#include <vector>
+
+struct MemoryRequest {
+  std::vector<std::function<void(void*)>> funcs;
+  std::vector<size_t> sizes;
+
+  size_t total_size();
+  void update_base_ptr(void* base);
+
+  template <typename T>
+  void append_pointer(T** ptr, size_t size) {
+    append_function([ptr](void* base) { *ptr = reinterpret_cast<T*>(base); }, size);
+  }
+  void append_function(std::function<void(void*)> func, size_t size);
+};
+
+class SharedMemBuffer {
+ public:
+  SharedMemBuffer();
+  ~SharedMemBuffer();
+
+  void alloc(void* object, MemoryRequest requests);
+
+ private:
+  void* buffer;
+  uint64_t size;
+  std::vector<MemoryRequest> object_requests;
+};
+
+static SharedMemBuffer shared_mem_buffer;
+static SharedMemBuffer shared_mem_buffer_for_decoder_layer;
+
+class SharedMemBufferNuma {
+  std::mutex lock;
+  std::map<size_t, std::unique_ptr<SharedMemBuffer>> numa_mem;
+
+ public:
+  void alloc(int numa, void* object, MemoryRequest requests);
+};
+
+static SharedMemBufferNuma shared_mem_buffer_numa;
+
+#endif