On Wed, Jan 26, 2011 at 02:33:56PM +0000, Alexander Konovalov wrote: > Dear Georges, > > On 25 Jan 2011, at 08:59, bolbita wrote: > > > Dear GAP Forum, > > > > I have little experience with GAP, and I wonder how can we control the > > execution time of a function. > > I dream about a function like > > UnderTimeControl := function (f, arg, maxtime) > > which would run the function f with arguments arg and a timer in parallel, > > and would return the result of f(arg) whenever its execution time is less > > than maxtime and would return fail > > otherwise. > > The current version of GAP is single-threaded so it's not directly possible > to have exactly the scenario you've described.However, there are several > possible workarounds of various difficulty and flexibility:
If that may help, this is how I implemented something similar in PARI/GP (which is also single-threaded): 1) add a signal handler for SIGALRM 2) call the C function alarm(maxtime); 3) evaluate f(arg). 4) if the signal handler is called, stop the evaluation and return fail. 5) if 3) complete, call alarm(0) to disable the alarm. Cheers, Bill. _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
