The BBN Advanced Computers subsidiary of Bolt Beranek & Newman Inc, Cambridge, Massachusetts is one of the handful of companies pulling out all the stops to create means to make parallel processors less daunting to program and to use, and the company’s latest offering is the Xtra integrated programming environment for its Butterfly GP1000 parallel processor. Xtra stands for X Tools for Runtime Analysis: based on the X Window System, it is claimed to be the first commercially available set of software tools to enable programmers to understand easily and to deal with the complexities inherent in multiprocessor systems. It makes full use of X Window’s multiple windows, mouse-driven inputs and pop-up menus so that the programmer can see a full picture of the program in real time, and so spot what is going wrong. Xtra includes a TotalView source-level multiprocess debugger to enable the programmer to watch the effects of many processes running simultaneously, and by having a group of related processes to share a single breakpoint via a single menu command, TotalView causes all related processes to stop so that the programmer can examine the state of any or all of them. Xtra will also integrate the company’s existing Gist graphics-oriented event display utility that enables programmers to analyse dynamic program behaviour, and by displaying a user-definable time sequence of events for each processor, it identifies performance bottlenecks. And BBN has added a graphical state display function and an event histogram utility so programmers can compare activity on different processors and ascertain program timing variability. TotalView is $5,000 and is available now for the Butterfly GP1000. Gist is bundled with the Butterfly and is planned to be an integrated Xtra module late this year, and additional modules will appear early next year.
