On 11/28/2014 11:58 AM, Ian Campbell wrote: > On Thu, 2014-11-27 at 12:51 +0200, Razvan Cojocaru wrote: > > It's a good idea to CC the relevant maintainers if you want their input. > >> Hello, >> >> I know that xc_interface_open() can be safely called several times from >> the same process, and that several processes can each have a bunch of >> xc_interface handles open, and that I shouldn't use an xc_interface >> inherited from the parent in a child process, because xenctrl.h says so. >> >> Is it safe to assume that the same restrictions / conventions apply to >> xs_handles obtained via xs_open()? Xenstore.h is not explicit. Looking >> at the code, it would seem safe to assume that it can be used in a >> similar manner, but it would be nice to have this confirmed if possible. > > I think there's a pretty good chance that the same applies to xenstore > connections made over the device/shared-ring interface. > > I'm not really sure about the semantics of a Unix domain socket after a > fork, but I don't expect both parent and child could sanely make use of > it. > > So I think the answer is: > > * Connections made with xs_open(0) (which might be shared page or > socket based) are only guaranteed to work in the parent after > fork. > * Connections made with xs_open(XS_OPEN_SOCKETONLY) will be usable > in either the parent or the child after fork, but not both. > * xs_daemon_open*() and xs_domain_open() are deprecated synonyms > for xs_open(0) > * XS_OPEN_READONLY has not bearing on any of this. > > Ian, does that seem right? > > Razvan, assuming Ian concurs with the above (or corrects it) then could > you knock up a patch to document the result please.
Sure, I'll document whatever gets confirmed. Thanks, Razvan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
