Paper#: 09 Title: Object Synchronization Pattern Authors: Anto'nio Rito Silva, Joa~o Pereira and Jose' Alves Marques Contact: Anto'nio Rito Silva INESC/IST Technical University of Lisbon R. Alves Redol 9, 1000 Lisboa, PORTUGAL e-mail: Rito.Silva@inesc.pt Phone: +351-1-3100287, Fax: +351-1-3145843 This paper describes the Object Synchronization pattern which decouples object synchronization from object concurrency and object functionality (sequential part). This pattern supports several synchronization policies and their customization. This pattern is used when invocations to a shared object need to be controlled in order to preserve its consistency. The solution described by this pattern provides encapsulation, modularity, extensibility and reuse of synchronization policies.