Hi Chris: For a bit of background information for my response to your comment below note that my counts show that 62 per cent of current plexit calls are associated with memory allocation errors, but I believe that fraction will quickly exceed 90 per cent once we become rigourous about checking for memory allocation issues. So what we do with the memory allocation errors potentially could matter a lot in terms of implementation/maintenance costs for our error report system.
On 2016-02-27 10:02-0500 Chris Marshall wrote: > The problem with immediate exit on memory errors > is that they cannot be caught. For example, trying to > make a perl binding to plplot would essentially crash > perl if the plplot did an exit. Understood. Memory allocation fails only because there are PLplot bugs in the size of memory requested or because the system is out of memory. Out of memory is clearly an emergency situation where the operating system is likely shutting down various programs arbitrarily in any case to try to claw back some memory. So under these emergency conditions an immediate exit from PLplot (and the calling environment like perl) is not a particularly bad tactic. And such out-of-memory emergency conditions are quite rare in any case. On the other hand, if we do make memory allocation errors part of our error report system, it does give at least some chance (if the OS does not kill the perl session first) for the user to save work in an out-of-memory emergency and if the issue is due to a PLplot size bug, it gives them (and us) a chance to replicate the issue and debug it further. So my conclusion is there is a modest benefit to making memory allocation errors part of the error report system, but that benefit has to be weighed against the implementation/maintenance costs. >From what Phil has said, if we can get the C setjmp/longjmp exception handling method of error reporting to work then including memory allocation errors as part of that report system would be fairly trivial so it would be a no-brainer to do that. But if we decide to use the return code method of error reporting the costs of including memory allocation errors in the system would be significantly higher (significantly more independent caller paths would have to be dealt with) so we would have to weigh those costs against the modest (in my view) benefit discussed above. Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); the Time Ephemerides project (timeephem.sf.net); PLplot scientific plotting software package (plplot.sf.net); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
