Merge branch 'master' into debian-r

[dak.git] / daklib / daksubprocess.py

diff --git a/daklib/daksubprocess.py b/daklib/daksubprocess.py
new file mode 100644 (file)
index 0000000..ff1df77
--- /dev/null
+++ b/daklib/daksubprocess.py
@@ -0,0 +1,70 @@
+"""subprocess management for dak
+
+@copyright: 2013, Ansgar Burchardt <ansgar@debian.org>
+@license: GPL-2+
+"""
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+import signal
+import subprocess
+
+#
+def fix_signal_handlers():
+    """reset signal handlers to default action.
+
+    Python changes the signal handler to SIG_IGN for a few signals which
+    causes unexpected behaviour in child processes. This function resets
+    them to their default action.
+
+    Reference: http://bugs.python.org/issue1652
+    """
+    for signal_name in ('SIGPIPE', 'SIGXFZ', 'SIGXFSZ'):
+        try:
+            signal_number = getattr(signal, signal_name)
+            signal.signal(signal_number, signal.SIG_DFL)
+        except AttributeError:
+            pass
+
+def _generate_preexec_fn(other_preexec_fn=None):
+    def preexec_fn():
+        fix_signal_handlers()
+        if other_preexec_fn is not None:
+            other_preexec_fn()
+    return preexec_fn
+
+def call(*args, **kwargs):
+    """wrapper around subprocess.call that fixes signal handling"""
+    preexec_fn = _generate_preexec_fn(kwargs.get('preexec_fn'))
+    kwargs['preexec_fn'] = preexec_fn
+    return subprocess.call(*args, **kwargs)
+
+def check_call(*args, **kwargs):
+    """wrapper around subprocess.check_call that fixes signal handling"""
+    preexec_fn = _generate_preexec_fn(kwargs.get('preexec_fn'))
+    kwargs['preexec_fn'] = preexec_fn
+    return subprocess.check_call(*args, **kwargs)
+
+def check_output(*args, **kwargs):
+    """wrapper around subprocess.check_output that fixes signal handling"""
+    preexec_fn = _generate_preexec_fn(kwargs.get('preexec_fn'))
+    kwargs['preexec_fn'] = preexec_fn
+    return subprocess.check_output(*args, **kwargs)
+
+def Popen(*args, **kwargs):
+    """wrapper around subprocess.Popen that fixes signal handling"""
+    preexec_fn = _generate_preexec_fn(kwargs.get('preexec_fn'))
+    kwargs['preexec_fn'] = preexec_fn
+    return subprocess.Popen(*args, **kwargs)