C#

static class HASPCLass
   {
     private static SerialPort m_port;
     private static bool m_initialized;
     private static int m_baudRate;
     static readonly object _syncObject = new object();
     public DoInitialization(int baudRate /*also could be other params*/)
     {
       lock(_syncObject)
       {
          if (!m_initialized)
          {
            Initialize(baudRate);
          }
       }
     }

     private Initialize(int baudrate /*also could have other params*/)
     {
        m_port.open(..);
        m_baudRate = baudRate;
        m_initialized = true;
     }

     private Uninitialize()
     {
        m_port.close();
        m_initialized = false;
     }



     public void Read(byte[] buff)
     {
       lock(_syncObject)
       {
         //Other custom read stuff
         m_port.Read(buff);
       }
     }

     public void Write(byte [] buff)
     {
       lock(_syncObject)
       {
         //Other write related code
         m_port.Write(buff);
       }
     }

     public void Close()
     {
       lock(_syncObject)
       {
          if (m_initialized)
          {
            Uninitialize();
          }
       }
     }
   }

public static void function1()
   {
    HASPClass.Read(...);

    // Some other code

    HASPClass.Write(...);
   }

   public static void function2()
   {
    HASPClass.Read(...);

    // Some other code

    HASPClass.Write(...);
   }

public static void function1()
  {
     lock(otherlock1)
     {
       HASPClass.Read(...);

       // Some other code

       HASPClass.Write(...);
      }
  }

  public static void function2()
  {
     lock(otherlock1)
     {
        HASPClass.Read(...);

        // Some other code

        HASPClass.Write(...);
      }
  }