From: Eric Wong Date: Tue, 17 May 2016 12:08:15 GMT Subject: Re: [RFD PATCH 0/3] Free all the memory! Message-ID: <20160517120815.GA15546@dcvr.yhbt.net> In-Reply-To: Eric Sunshine wrote: > On Mon, May 16, 2016 at 11:22 PM, Stefan Beller wrote: > > When using automated tools to find memory leaks, it is hard to distinguish > > between actual leaks and intentional non-cleanups at the end of the program, > > such that the actual leaks hide in the noise. > > Considering the signal-to-noise ratio mentioned above, the goal seems > reasonable, but why pollute the code with #ifdef's all over the place > by making the cleanup conditional? If you're going though the effort > of plugging all these leaks, it probably makes sense to do them > unconditionally. I haven't checked for git, but I suspect we get speedups by not calling free(). I've never needed to profile git, but free() at exit has been a measurable bottleneck in other projects I've worked on. Often, free() was more expensive than *alloc(). In any case, I like constant conditionals in C or inline wrappers macros over CPP #ifdefs littered inside functions: /* in git-compat-util.h */ #ifdef FREE_ALL_MEMORY static inline void optional_free(void *ptr) {} #else # define FREE_ALL_MEMORY (0) # define optional_free(ptr) free(ptr) #endif /* inside any function: */ if (FREE_ALL_MEMORY) big_function_which_calls_multiple_frees(); Also Valgrind has suppression files, so code modifications may not be necessary at all.