On 2016-02-26 22:45-0500 Hazen Babcock wrote: > On 02/26/2016 05:18 PM, Alan W. Irwin wrote: [...] >> But I have to admit you [Phil] have >> already made a fairly convincing argument for error reporting via C >> exception handling, and if you look at the caller graphs I prepared >> there are some instances (even if we have immediate exit for memory >> emergencies) where the return value approach would be quite >> complicated. > > Such as?
Hi Hazen: To give you an immediate fairly complex example look at the call graph and caller graph of grline in <http://plplot.sourceforge.net/doxygen/html/plcore_8c.html>. The caller graph includes some 50 functions while its call graph includes calls to plexit and one of those calls in plsave_set_locale is not anything to do with memory allocation so there is no question we would have to deal with it in our error report system. So that is already a pretty complicated example, but I just discovered that is just scratching the surface because the large call/caller graphs generated by doxygen are partitioned (as indicated by the red box around some references) so a given caller graph being presented on a single plot is in complex cases a subset of the complete result. For example, the caller graph for plsave_set_locale (in <http://plplot.sourceforge.net/doxygen/html/plctrl_8c.html> this time) does not include all the complications of the grline caller graph. Instead, it summarizes that 50-function call graph as a red box around grline with no further details. So I think to get the full picture for either a large call graph or caller graph you have to click on all the red boxes. Anyhow, please browse and click on these graphs including the red boxes to draw your own conclusions about the complexity of the call graphs that the return code approach for error reporting would have to deal with. I will stop there because I don't have the technical expertise to answer the concerns you expressed about using C exception handling (implemented with setjmp/longjmp) as the complete basis of the error reporting system for PLplot that Phil apparently has in mind. However, I assume Phil will answer your concerns. 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
