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c [2015/12/31 09:32]
admin [Use goto]
c [2015/12/31 09:35]
admin [Single return point]
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 I've been writing c for over 30 years, but it can still be a nightmare - the problems are well documented elsewhere. The discipline of writing device drivers for Linux/Solaris/HP-UX/AIX etc etc and crypto code for RSA (thanks, Michael for the excellent code-reviews - I learned so much) have led to a few points that help make code clearer, easier to maintain and less likely to contain memory leaks and other faults. I've been writing c for over 30 years, but it can still be a nightmare - the problems are well documented elsewhere. The discipline of writing device drivers for Linux/Solaris/HP-UX/AIX etc etc and crypto code for RSA (thanks, Michael for the excellent code-reviews - I learned so much) have led to a few points that help make code clearer, easier to maintain and less likely to contain memory leaks and other faults.
 ====Single return point==== ====Single return point====
-Every routine should have a single return point. All possible execution paths go through this point and therefore have the chance to have resources released. The main thing, of course, is to free resources that are no longer needed eg memory that has been malloc()'ed, file/socket descriptors and in device drivers, to release DMA and interrupt resources.+Every routine should have a single return point. All possible execution paths go through this point and therefore have the chance to have resources released. The main thing, of course, is to free resources that are no longer needed eg memory that has been malloc()'ed, file/socket descriptors and in device drivers, to release DMA and interrupt resources. See the following example.
 ====Error responses should be close to the failing statement==== ====Error responses should be close to the failing statement====
 and not dangling at the end of some huge }}}} block ten pages away!!! Deal with it _now_, to hell with making the Happy Path clearer - the Happy Path is easy, it's the errors that make the thing beastly. and not dangling at the end of some huge }}}} block ten pages away!!! Deal with it _now_, to hell with making the Happy Path clearer - the Happy Path is easy, it's the errors that make the thing beastly.
c.txt · Last modified: 2020/10/17 09:05 by 114.119.151.1