# HG changeset patch
# User Yuya Nishihara <yuya@tcha.org>
# Date 1479383829 -32400
# Node ID 03f7aa2bd0e3129f4cb05de09b25e726dc252a4c
# Parent  f2d13eb8519886f86a312467ca411e47f6998497
worker: discard waited pid by anyone who noticed it first

This makes sure all waited pids are removed before calling killworkers()
even if waitpid()-pids.discard() sequence is interrupted by another SIGCHLD.

diff -r f2d13eb85198 -r 03f7aa2bd0e3 mercurial/worker.py
--- a/mercurial/worker.py	Thu Nov 17 21:08:58 2016 +0900
+++ b/mercurial/worker.py	Thu Nov 17 20:57:09 2016 +0900
@@ -111,11 +111,14 @@
                     if e.errno == errno.EINTR:
                         continue
                     elif e.errno == errno.ECHILD:
-                        break # ignore ECHILD
+                        # child would already be reaped, but pids yet been
+                        # updated (maybe interrupted just after waitpid)
+                        pids.discard(pid)
+                        break
                     else:
                         raise
             if p:
-                pids.remove(p)
+                pids.discard(p)
                 st = _exitstatus(st)
             if st and not problem[0]:
                 problem[0] = st