SubProcess: use non-blocking waitpid

This ensures that the EventLoop will not stop due to a waitpid call
blocking forever.

diff --git a/pym/_emerge/SubProcess.py b/pym/_emerge/SubProcess.py
index 926efa72b2dcdc132eabba3367b3b3eeb2126e99..01004a874f36b6ca363bc610591058d3bfa4e207 100644 (file)
--- a/pym/_emerge/SubProcess.py
+++ b/pym/_emerge/SubProcess.py
@@ -20,6 +20,9 @@ class SubProcess(AbstractPollTask):
        # we've sent a kill signal to our subprocess.
        _cancel_timeout = 1000 # 1 second
 
+       # Poll interval for process exit status.
+       _waitpid_interval = 1000 # 1 second
+
        def _poll(self):
                if self.returncode is not None:
                        return self.returncode
@@ -77,7 +80,7 @@ class SubProcess(AbstractPollTask):
                                                self._orphan_process_warn()
                        else:
                                self._wait_loop()
-                       self._unregister()
+
                        if self.returncode is not None:
                                return self.returncode
 
@@ -87,6 +90,25 @@ class SubProcess(AbstractPollTask):
                                "%s: pid is non-integer: %s" %
                                (self.__class__.__name__, repr(self.pid)))
 
+               self._waitpid_loop()
+
+               return self.returncode
+
+       def _waitpid_loop(self):
+               if not self._waitpid_cb():
+                       return
+
+               timeout_id = self.scheduler.timeout_add(
+                       self._waitpid_interval, self._waitpid_cb)
+               try:
+                       while self.returncode is None:
+                               self.scheduler.iteration()
+               finally:
+                       self.scheduler.source_remove(timeout_id)
+
+       def _waitpid_cb(self):
+               if self.returncode is not None:
+                       return False
                try:
                        # With waitpid and WNOHANG, only check the
                        # first element of the tuple since the second
@@ -97,21 +119,13 @@ class SubProcess(AbstractPollTask):
                                raise
                        del e
                        self._set_returncode((self.pid, 1 << 8))
+                       return False
                else:
                        if wait_retval[0] != 0:
                                self._set_returncode(wait_retval)
-                       else:
-                               try:
-                                       wait_retval = os.waitpid(self.pid, 0)
-                               except OSError as e:
-                                       if e.errno != errno.ECHILD:
-                                               raise
-                                       del e
-                                       self._set_returncode((self.pid, 1 << 8))
-                               else:
-                                       self._set_returncode(wait_retval)
+                               return False
 
-               return self.returncode
+               return True
 
        def _orphan_process_warn(self):
                pass
@@ -141,6 +155,7 @@ class SubProcess(AbstractPollTask):
                subprocess.Popen.returncode: A negative value -N indicates
                that the child was terminated by signal N (Unix only).
                """
+               self._unregister()
 
                pid, status = wait_retval