On Feb 26, 2010, at 10:34 PM, Eric Veith1 wrote: > Dear list, > > I'm wrinting a perl program that works with different threads.
Your first sentence already has me worried. Threads are un-fun. > Those > threads depend on each other, not all in the same way. Some threads should > stop when others are finished with their work, and again others are to be > started afterwards. Now getting really complex. > I have six worker machines, M1 to M6, and a controller machine, M0. The > perl program runs on the controller machine. This program is basically a > dispatcher I control from a command line interface. A command causes two > threads to be started, say on M1 and M2. At this point, these are really processes. Threads are in the kernel, you are just starting a separate process on two different machines. > One thread on M1 produces work, > the other on M2 plots the network traffic. When M1 is finished, I want the > thread M0 that caused the workload to signal to the dispatcher that M1 is > finished. The dispatcher then shall signal M2 to stop monitoring. > Afterwards, I want the results from both M1 and M2, preferably in form of > a perl structure. These are all separate processes, not threads. Are you sure you need to use threads? In general a thread is something that runs _inside_ a process. http://en.wikipedia.org/wiki/Thread_(computer_science) > First of all, is that possible? Yes. Not that hard. You have exit values from your process so you can trap that and do something based on your exit value. > > I have already looked at threads, threads::shared and the traditional > fork(). With the standard IPC stuff, I'm able to signal and trap that in > the master process with a signal handler. But I cannot, however, get the > PID of the child that emitted the signal, thus I'm not able to send a > SIGTERM to another process. I'm also not sure how I could get my result > data. Well, why not just create something in a perl structure and just use something like the Storable module or YAML to dump it to disk and you can read it from your other machine. > > threads::shared allows me to share a perl structure I could fill, but I > don't know how to signal the master thread. Passing a subroutine reference > doesn't work, of other options I don't know. > > I'd very much appreciate any hints. I would avoid threads. I would have a program / process on machine 0 that fires off another program / process on machine 1. Then I guess you need to fire off your program on machine 2 to do network monitoring (?). When the program on 1 is finished, it dumps its data to disk and call machine 0 who in turn calls 2. Jeremiah -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
