Greg -- Since IO is implementation dependent, standard MUMPS does not say anything that I am aware of about supporting or not supporting named pipes (FIFOs).
Note that GT.M does support IO to FIFOs and does have a means for an M process to handle an asynchronous interrupt (SIGUSR1), and it's all done with M code. One of the benefits of deploying a server under [x]inetd is that the process goes away when the client disconnects, and nothing needs to be done to shut it down, either by having it poll for a message or handle an asynchronous signal. -- Bhaskar On Fri, 2005-07-29 at 12:27 -0500, Greg Woodhouse wrote: > Also, bear in mind that starting and stopping background processes in > VistA is not instantaneous. Unfortunately, standard MUMPS doesn't > providwe support for mechanisms like FIFOs or even signals. > Unfortunately, this means that it is necessary for background > processes > to implement some kind of polling technique to determine if they > should > stop. But this is problematic, too. for one thing, it is all too easy > to write a process that spends a significant amount of its time > actually polling globals for a "stop flag" or something similar. If > this is done thoughtlessly, it can bring a system to its knees, and > any > practical implementation is going to have to throttle this process > back > enough so that it consumes only a small percentage of processing time > (and, potentially, direct I/O). > > Now, asynchronous delivery of signals (a perfect job for SSVNs, IMO) > is > a much more efficient (and typical) way of solving the same problem. > Certainly, if I were to code a solution to this problem in C, I would > not rely on a mechanism so primitive as a polling loop. > <soapbox>This is yet another reason I continue to argue that the > language standard needs to be updated.</soapbox> ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ Hardhats-members mailing list Hardhats-members@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hardhats-members
