add balance-serve, support concurrence

csrc/balance_serve/kvc2/src/utils/mutex_extend.hpp

@@ -0,0 +1,70 @@
+#ifndef __MUTEX_EXTEND_HPP_
+#define __MUTEX_EXTEND_HPP_
+
+#include <atomic>
+#include <chrono>
+#include <iostream>
+#include <thread>
+
+class non_recursive_mutex {
+ public:
+  non_recursive_mutex() = default;
+
+  // 使用 try_lock 实现非递归锁
+  bool try_lock() {
+    std::thread::id this_id = std::this_thread::get_id();
+
+    // 检查当前线程是否已经持有该锁
+    if (owner.load(std::memory_order_acquire) == this_id) {
+      return false;  // 如果是当前线程，返回失败
+    }
+
+    // 尝试加锁
+    if (mtx.try_lock()) {
+      owner.store(this_id, std::memory_order_release);  // 设置锁的拥有者
+      return true;
+    }
+
+    return false;
+  }
+
+  // lock 会阻塞，直到获得锁
+  void lock() {
+    std::thread::id this_id = std::this_thread::get_id();
+
+    while (true) {
+      // 检查当前线程是否已经持有该锁
+      if (owner.load(std::memory_order_acquire) == this_id) {
+        throw std::runtime_error("Thread is trying to lock a mutex it already holds");
+      }
+
+      // 尝试加锁
+      if (mtx.try_lock()) {
+        owner.store(this_id, std::memory_order_release);  // 设置锁的拥有者
+        return;
+      }
+
+      // 如果锁未获得，则稍微等待，防止忙等
+      std::this_thread::yield();
+    }
+  }
+
+  // 解锁
+  void unlock() {
+    std::thread::id this_id = std::this_thread::get_id();
+
+    // 确保只有持有锁的线程可以解锁
+    if (owner.load(std::memory_order_acquire) == this_id) {
+      owner.store(std::thread::id(), std::memory_order_release);  // 清除锁的拥有者
+      mtx.unlock();
+    } else {
+      throw std::runtime_error("Thread attempting to unlock a mutex it doesn't own");
+    }
+  }
+
+ private:
+  std::mutex mtx;                      // 实际的互斥量
+  std::atomic<std::thread::id> owner;  // 原子变量，记录当前锁的拥有者
+};
+
+#endif