Hi Eric, On Aug 11 11:51, Erik Bray wrote: > [...] > > Existing implementations vary on the result of a kill() with pid indicating > > an inactive process (a > > terminated process that has not been waited for by its parent). Some > > indicate success on such a > > call (subject to permission checking), while others give an error of > > [ESRCH]. Since the definition > > of process lifetime in this volume of POSIX.1-2008 covers inactive > > processes, the [ESRCH] error > > as described is inappropriate in this case. In particular, this means that > > an application cannot > > have a parent process check for termination of a particular child with > > kill(). (Usually this is done > > with the null signal; this can be done reliably with waitpid().) > > In response to the originally issue, this was fixed *specifically* for > the case of kill(pid, 0). But my reading of the above is that kill() > should return 0 in this case regardless of the signal (modulo > permissions, etc.). On Linux, for example, when calling kill with pid > of a zombie process the kernel will happily deliver the signal to the > relevant task_struct; it will just never be acted on since the task > will never run again.
I'm not sure why cgf only fixed that for sig 0 at the time, since, as you noted, the text from POSIX-1.2008 does not state that this is *restricted* to sig 0. > The below (untested) patch demonstrates the change I'm suggesting, > though I don't know what other code, if any, might be involved in > this. The original patch laid the groundwork by making sure that there are two states, EXITED and REAPED. Removing the explicit check for 0 is the right thing to do, afaics, so I tested and applied your patch as is, see https://cygwin.com/git/?p=newlib-cygwin.git;a=commitdiff;h=86f79af827729f3968d8b3b8f860ac29d200da0d Thanks, Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat
signature.asc
Description: PGP signature
