On Mon, Sep 26, 2016 at 09:21:10PM +0200, Lars Schneider wrote: > On 25 Sep 2016, at 13:26, Jakub Narębski <jna...@gmail.com> wrote: > > > W dniu 20.09.2016 o 21:02, larsxschnei...@gmail.com pisze: > >> From: Lars Schneider <larsxschnei...@gmail.com> > >> ... > >> > >> +static int packet_write_gently(const int fd_out, const char *buf, size_t > >> size) > > > > I'm not sure what naming convention the rest of Git uses, but isn't > > it more like '*data' rather than '*buf' here? > > pkt-line seems to use 'buf' or 'buffer' for everything else.
I do not think we have definite rules, but I would generally expect to see "data" as an opaque thing (e.g., passing "void *data" to callbacks). "buf" or "buffer" makes sense here, but I don't think it really matters that much either way. > >> + static char packet_write_buffer[LARGE_PACKET_MAX]; > > > > I think there should be warning (as a comment before function > > declaration, or before function definition), that packet_write_gently() > > is not thread-safe (nor reentrant, but the latter does not matter here, > > I think). > > > > Thread-safe vs reentrant: http://stackoverflow.com/a/33445858/46058 > > > > This is not something terribly important; I guess git code has tons > > of functions not marked as thread-unsafe... > > I agree that the function is not thread-safe. However, I can't find > an example in the Git source that marks a function as not thread-safe. > Unless is it explicitly stated in the coding guidelines I would prefer > not to start way to mark functions. I'd agree. A large number of functions in git are not reentrant, and I would not want to give the impression that those missing a warning are safe to use. > >> + if (size > sizeof(packet_write_buffer) - 4) { > > > > First, wouldn't the following be more readable: > > > > + if (size + 4 > LARGE_PACKET_MAX) { > > Peff suggested that here: > http://public-inbox.org/git/20160810132814.gqnipsdwyzjmu...@sigill.intra.peff.net/ There is a good reason to do size checks as a subtraction from a known quantity: you can be sure that you are not introducing an overflow (e.g., Jakub's suggestion does the wrong thing when "size" is within 4 bytes of its maximum value). That's unlikely in this case, but then so is the size exceeding LARGE_PACKET_MAX in the first place (arguably this should be a die("BUG"), because it is the caller's responsibility to split their packets. -Peff
