EMUs: Eiffel Multi Users

The Parts

  • EMU-Protocol
  • EMU-Server
  • EMU-Client
  • ES integration

Developer Requirements


defines Client/Server communication with

  • client/server states
  • available messages
  • client/server actions

You can find our complete Protocol Specification here


  • stores and manages code-repository
  • synchronizes code of clients
  • manages Locking-System
  • Account-System
  • project update
  • add/create new code (classes)
  • change-logging
  • optional: Media-upload
  • optional: BackUp-System
  • optional: Release-versions
  • optional: Server-Admin-Tool


  • list of locked code
  • check if code (class) is locked
  • lock / unlock code (class)


  • broadcast code-changes
  • bring user code up to date


The server uses an account-system to organize its projects and users. Every project has its own users assigned.


  • project name
  • project-admin(s)
  • user lists
  • project status
  • editable / creatable with a project-admin-tool


  • usernames
  • used for logins
  • assign locked code & changes to users
  • online status


The Log helps the users to know what has changed during their last login. It is also used as a look-up table for synchronisation with the clients. Every lock/unlock action is logged with following data:

  • user name
  • date and time
  • type of action
  • code element (class name)

Additionally, it provides the possibility for the user to add comments (e.g what he changed, what doesn't work yet...).


  • interface for IDE and server
  • provides features to login and communicate with server on an abstract base
  • upload/download code elements to/from server
  • notify IDE of server-messages (code-updates)
  • modular / independent of IDE-integration
  • optional: upload media files


The client needs to notify the IDE of the new changes.

ES integration

  • minimal change to existing ES-classes and features.
  • modular integration: activatable and removable / hideable
  • only a few GUI changes

ES-GUI Enhancement

  • Emu-Toolbar [Upload,Download,Lock,Unlock and start external wizards]

Internal Dialogs

External Wizards

New EMU Project Wizard

The following states need to be reflected by the wizard:

  • emu-server hostname and port
  • project-name and project-password
  • add ES-libraries used
  • add users and user-passwords

User Requirements

  • easy to use
  • target is a small project group of up to 20 developers.
  • code synchronisation process mostly hidden from user
  • minimal extra work (less total work)
  • better efficiency