On 07/20/2010 03:52 PM, Paul Eggert wrote: > On 07/20/10 14:47, Eric Blake wrote a bunch of good questions, > ending with: > >> And how does signal handling fit in with interrupting a child test? > > OK, you're right, a plain pipe is not going to work. How about > this much-smaller fix instead? It builds on your idea to make > sure that the 'read at_token' commands succeed. > > @@ -1410,7 +1410,9 @@ dnl kill -13 $$ > fi > shift # Consume one token. > if test $...@%:@] -gt 0; then :; else > - read at_token <&AT_JOB_FIFO_FD || break > + # The 'until' loop avoids a race condition if we happen to open > + # the fifo between the time a child outputs a token and it exits. > + until read at_token; do :; done <&AT_JOB_FIFO_FD
Hmm - IIUC, the '|| break' that you are deleting is there in case something kills off the child and it never gets around to writing a token, at which point we've now put the parent into an inf-loop waiting for a token that will never arrive. Are we sure we want to do this? -- Eric Blake ebl...@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org
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