On 06/04/2013 02:23 PM, Alon Levy wrote: > Used by the followin patch. s/followin/following/
> > +int qemu_pipe_non_block(int pipefd[2]) > +{ > + int ret; > + > + ret = qemu_pipe(pipefd); qemu_pipe() already uses pipe2() when available; it seems like it would be nicer to use pipe2's O_NONBLOCK option directly in one syscall (where supported) instead of having to make additional syscalls after the fact. Would it just be smarter to change the signature of qemu_pipe() to add a bool block parameter, and then change the 5 existing callers to pass false with your later patch in the series passing true, and do it without creating a new wrapper? > + if (ret) { > + return ret; > + } > + if (fcntl(card->pipe[0], F_SETFL, O_NONBLOCK) == -1) { > + return -errno; > + } > + if (fcntl(card->pipe[1], F_SETFL, O_NONBLOCK) == -1) { > + return -errno; Leaks fds. If you're going to report error, then you must close the fds already created. > + } > + if (fcntl(card->pipe[0], F_SETOWN, getpid()) == -1) { > + return -errno; Same comment about fd leaks. This part seems like a useful change, IF you plan on using SIGIO and SIGURG signals; and it is something which pipe2() cannot optimize, so I can see why you are adding a new function instead of changing qemu_pipe() and adjust all its callers to pass an additional parameter. But are you really planning on using SIGIO/SIGURG? Furthermore, this is undefined behavior. According to POSIX, use of F_SETOWN is only portable on sockets, not pipes. It may work on Linux, but you'll need to be aware of what it does on other platforms. http://pubs.opengroup.org/onlinepubs/9699919799/functions/fcntl.html -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
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