Reactor vs Proactor

README.md

• Reactor vs Proactor (text): http://didawiki.cli.di.unipi.it/lib/exe/fetch.php/magistraleinformatica/tdp/tpd_reactor_proactor.pdf
• Reactor (video): https://www.youtube.com/watch?v=pmtrUcPs4GQ
• Proactor (video): https://www.youtube.com/watch?v=2rGOX8Oy7-Q

proactor.cpp

void proact(Proactor& proactor, Socket& socket) {
  proactor.recv(socket, [](char* buffer, int size) {
    // Call me when you've read the socket and give me what you read.
  });
}

class ReactorAsProactor : public Proactor {
public:
  ReactorAsProactor(private Reactor& reactor) {}
  
  template <typename Handler>
  void recv(Socket& socket, Handler const& handler) {
    this.reactor.recv(socket, [&]() {
      char buffer[256];
      int size;
      do {
        size = socket.read(buffer, 256);
        handler(buffer, size);
      } while (size == 256);
    });
  }
};

reactor.cpp

void react(Reactor& reactor, Socket& socket) {
  reactor.recv(socket, [&]() {
    // Call me when the socket is ready for reading.
    char buffer[256];
    int size;
    do {
      size = socket.read(buffer, 256);
    } while (size == 256);
  });
}

class ProactorAsReactor : public Reactor {
public:
  ProactorAsReactor(private Proactor& proactor) {} // C#/TypeScript-style shorthand
  
  template <typename Handler>
  void recv(Socket& socket, Handler const& handler) {
    this.proactor.recv(socket, [](char* buffer, int size) {
      socket.unread(buffer, size); // Socket is our own abstraction, so we can do this.
      handler();
    });
  }
};