integrating the existing state of TON Storage / TON Payments / CPS Fift development branches

storage/SharedState.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include <atomic>
+#include "td/utils/MovableValue.h"
+#include <memory>
+
+namespace td {
+template <class T>
+class SharedState {
+ public:
+  friend class Guard;
+  class Guard {
+   public:
+    Guard(Guard &&) = default;
+    Guard(SharedState<T> *self) : self(self) {
+      CHECK(!self->data_->is_locked.exchange(true));
+    }
+    ~Guard() {
+      if (self.get()) {
+        CHECK(self.get()->data_->is_locked.exchange(false));
+      }
+    }
+    T *get() {
+      return &self.get()->data_->data;
+    }
+    T *operator->() {
+      return get();
+    }
+
+   private:
+    td::MovableValue<SharedState<T> *> self;
+  };
+
+  auto lock() {
+    return Guard{this};
+  }
+  auto unsafe() {
+    return &data_->data;
+  }
+
+ private:
+  struct Data {
+    std::atomic<bool> is_locked{};
+    T data;
+  };
+  std::shared_ptr<Data> data_{std::make_shared<Data>()};
+};
+}  // namespace td