killdaemons: close pid file before killing processes With #serve enabled on Windows, I was getting occasional stacktraces like this: Errored test-hgweb-json.t: Traceback (most recent call last): File "./run-tests.py", line 724, in run self.tearDown() File "./run-tests.py", line 805, in tearDown killdaemons(entry) File "./run-tests.py", line 540, in killdaemons logfn=vlog) File "...\tests\killdaemons.py", line 94, in killdaemons os.unlink(pidfile) WindowsError: [Error 32] The process cannot access the file because it is being used by another process: '...\\hgtests.zmpqj3\\child80\\daemon.pids' Adrian suggested using util.posixfile, which works. However, the 'mercurial' package isn't in sys.path when invoking run-tests.py, and it isn't clear that hacking[1] it in is a good thing (especially for test-run-tests.t, which uses an installation in a temp folder). I tried using ProcessMonitor to figure out what the other process is, but that monitoring slows things down to such a degree that the issue doesn't occur. I was ready to blame the virus scanner, but it happens without that too. Looking at the code, I don't see anything that would have the pid file open. But I was able to get through about 20 full test runs without an issue with this minor change, whereas before it was pretty certain to hit this at least once in two or three runs. [1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-May/097907.html

--- a/tests/killdaemons.py	Sun May 21 18:58:51 2017 -0400
+++ b/tests/killdaemons.py	Mon May 22 21:45:02 2017 -0400
@@ -78,18 +78,20 @@
         logfn = lambda s: s
     # Kill off any leftover daemon processes
     try:
-        fp = open(pidfile)
-        for line in fp:
-            try:
-                pid = int(line)
-                if pid <= 0:
-                    raise ValueError
-            except ValueError:
-                logfn('# Not killing daemon process %s - invalid pid'
-                      % line.rstrip())
-                continue
+        pids = []
+        with open(pidfile) as fp:
+            for line in fp:
+                try:
+                    pid = int(line)
+                    if pid <= 0:
+                        raise ValueError
+                except ValueError:
+                    logfn('# Not killing daemon process %s - invalid pid'
+                          % line.rstrip())
+                    continue
+                pids.append(pid)
+        for pid in pids:
             kill(pid, logfn, tryhard)
-        fp.close()
         if remove:
             os.unlink(pidfile)
     except IOError: