Definition and Implementation of a Flexible Communication Primitive for Distributed Programming

Distributed programming has to face problems due to asynchro-nism of underlying communication networks. If for some applications the only use of FIFO channels eliminates the undesired eeects due to asynchro-nism, this is generally not suucient. Total or causal order of deliveries of messages have been proposed to overcome such problems but in some cases these orders impose a too strong property that can reduce the potential parallelism of the application. This paper proposes a exible broadcast primitive that attaches a type (ordinary or causal) to each message; these types impose constraints on messages deliveries. In that way the programmer is able to exploit the potential parallelism of his application in order to get an eecient program. Une primitive de communication exible pour les applications r eparties R esum e : Cet article propose une primitive de communication r epartie, qui attache un type a tout message diius e. Ce type impose des contraintes sur la livraison du message auquel il est associ e. Ainsi un message causal ne peut ^ etre d elivr e que lorsque tous les messages diius es dans son pass e l'on et e, alors que la livraison d'un message ordinaire n'est a priori pas contrainte. Cette exibilit e permet au programmeur de mieux exploiter le parall elisme pr esent dans son application. La primitive propos ee peut ^ etre vue comme une extension de l'ordre causal et des ush-channels.