Method and apparatus for synchronized message passing using shared resources

This invention relates generally to communications in a computer system and more particularly to performing synchronized message passing in a computer system using shared resources. Techniques used in communicating messages between processes are described using a shared message buffer pool and incoming message lists associated with each process. Associated with each process is message management information. Using the message management information, incoming messages to a process are retrieved, outgoing messages to another process are sent, and message buffers are allocated as needed from a free message buffer list. The free message buffer list is a shared resource from which processes obtain a free message buffer to send a message to another process. Access to the shared free message buffer list and process message lists is synchronized through discipline imposed upon updating and accessing various fields of the data structure without requiring a global locking mechanism for synchronization of shared resources.