An Efficient Shared Memory Layer for Distributed Memory Machines.
Daniel J. Scales, Monica S. Lam · 1994
This report describes a system called SAM that simplifies the task of programming machines with distributed address spaces by providing a shared name space and dynamic caching of remotely accessed data. SAM makes it possible to utilize the computational power available in networks of workstations and distributed memory machines, while getting the ease of programming associated with a single address space model. The global name space and caching are especially important for complex scientific applications with irregular communication and parallelism. SAM is based on the principle of tying synchronization with data accesses. Precedence constraints are expressed by accesses to single-assignment values, and mutual exclusion constraints are represented by access to data items called accumulators. Programmers easily express the communication and synchronization between processes using these operations; they can also use alternate paradigms that are built with the SAM primitives. Operations f...