Use ctypes in subprocess for bug #448858.

Isolate ctypes usage in a subprocess, in order to avoid potential
problems with stale cached libraries as described in bug #448858,
comment #14 (also see http://bugs.python.org/issue14597).

1 files changed, 53 insertions, 0 deletions

diff --git a/pym/portage/dbapi/_SyncfsProcess.py b/pym/portage/dbapi/_SyncfsProcess.py
new file mode 100644
index 000000000..7518214ec
--- /dev/null
+++ b/pym/portage/dbapi/_SyncfsProcess.py
@@ -0,0 +1,53 @@
+# Copyright 2012 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+from portage import os
+from portage.util._ctypes import find_library, LoadLibrary
+from portage.util._async.ForkProcess import ForkProcess
+
+class SyncfsProcess(ForkProcess):
+	"""
+	Isolate ctypes usage in a subprocess, in order to avoid
+	potential problems with stale cached libraries as
+	described in bug #448858, comment #14 (also see
+	http://bugs.python.org/issue14597).
+	"""
+
+	__slots__ = ('paths',)
+
+	@staticmethod
+	def _get_syncfs():
+
+		filename = find_library("c")
+		if filename is not None:
+			library = LoadLibrary(filename)
+			if library is not None:
+				try:
+					return library.syncfs
+				except AttributeError:
+					pass
+
+		return None
+
+	def _run(self):
+
+		syncfs_failed = False
+		syncfs = self._get_syncfs()
+
+		if syncfs is not None:
+			for path in self.paths:
+				try:
+					fd = os.open(path, os.O_RDONLY)
+				except OSError:
+					pass
+				else:
+					try:
+						if syncfs(fd) != 0:
+							# Happens with PyPy (bug #446610)
+							syncfs_failed = True
+					finally:
+						os.close(fd)
+
+		if syncfs is None or syncfs_failed:
+			return 1
+		return os.EX_OK