Add some pieces of an IPC framework that will eventually allow ebuild

processes can to communicate with portage's main python process.

Here are a few possible uses:

1) Robust subshell/subprocess die support. This allows the ebuild
   environment to reliably die without having to rely on signal IPC.

2) Delegation of portageq calls to the main python process, eliminating
   performance and userpriv permission issues.

3) Reliable ebuild termination in cases when the ebuild has accidentally
   left orphan processes running in the backgraound (as in bug 278895).

1 files changed, 71 insertions, 0 deletions

diff --git a/bin/ebuild-ipc.py b/bin/ebuild-ipc.py
new file mode 100755
index 000000000..43a526582
--- /dev/null
+++ b/bin/ebuild-ipc.py
@@ -0,0 +1,71 @@
+#!/usr/bin/python
+# Copyright 2010 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+#
+# This is a helper which which ebuild processes can use
+# to communicate with portage's main python process.
+
+import os
+import pickle
+import select
+import sys
+
+# Avoid sandbox violations after python upgrade.
+pym_path = os.path.join(os.path.dirname(
+	os.path.dirname(os.path.realpath(__file__))), "pym")
+if os.environ.get("SANDBOX_ON") == "1":
+	sandbox_write = os.environ.get("SANDBOX_WRITE", "").split(":")
+	if pym_path not in sandbox_write:
+		sandbox_write.append(pym_path)
+		os.environ["SANDBOX_WRITE"] = \
+			":".join(filter(None, sandbox_write))
+
+import portage
+
+class EbuildIpc(object):
+
+	def __init__(self):
+		self.fifo_dir = os.environ['PORTAGE_BUILDDIR']
+		self.ipc_in_fifo = os.path.join(self.fifo_dir, '.ipc_in')
+		self.ipc_out_fifo = os.path.join(self.fifo_dir, '.ipc_out')
+		self.ipc_lock_file = os.path.join(self.fifo_dir, '.ipc_lock')
+
+	def communicate(self, args):
+		lock_obj = portage.locks.lockfile(self.ipc_lock_file, unlinkfile=True)
+		try:
+			return self._communicate(args)
+		finally:
+			portage.locks.unlockfile(lock_obj)
+
+	def _communicate(self, args):
+		fifo_dir = os.environ['PORTAGE_BUILDDIR']
+		ipc_in_fifo = os.path.join(fifo_dir, '.ipc_in')
+		ipc_out_fifo = os.path.join(fifo_dir, '.ipc_out')
+		input_fd = os.open(ipc_out_fifo, os.O_RDONLY|os.O_NONBLOCK)
+		input_file = os.fdopen(input_fd, 'rb')
+		output_file = open(ipc_in_fifo, 'wb')
+		pickle.dump(args, output_file)
+		output_file.flush()
+
+		events = select.select([input_file], [], [])
+		if input_file in events[0]:
+			reply = pickle.load(input_file)
+		else:
+			reply = None
+
+		output_file.close()
+		input_file.close()
+
+		if reply == 'OK':
+			rval = os.EX_OK
+		else:
+			rval = 1
+
+		return rval
+
+def ebuild_ipc_main(args):
+	ebuild_ipc = EbuildIpc()
+	return ebuild_ipc.communicate(args)
+
+if __name__ == '__main__':
+	sys.exit(ebuild_ipc_main(sys.argv[1:]))