Active Messages: simple, fast, and flexible communication
				   
			   David E. Culler
		  Computer Science Division --- EECS
	     University of California, Berkeley, CA 94720
			culler@cs.Berkeley.edu
				   
Active Messages is a simple communication primitive that makes the
full capabilities of modern MPP communication hardware available to
user-level parallel programming system.  The implementation on the
CM-5 and nCUBE/2 exhibits an order of magnitude less overhead than the
send/receive model for which the machines were designed.  Its
flexibility has been demonstrated by realizations of shared memory,
message passing, dataflow and various hybrid models on the same
machine.  The simplicity of Active Messages comes about by separating
complex storage management and scheduling from basic communication.
The higher level programming system or communication library can layer
the additional functionality that it requires or it can seek to
exploit frequently occurring simple cases.  We are currently developing
Active Messages on other platforms and less robust networks.