From e489dcef3fd91ecf4a0960bdd7ed1de0a992f72b Mon Sep 17 00:00:00 2001
From: Zac Medico <zmedico@gentoo.org>
Date: Fri, 4 Jan 2013 05:22:48 -0800
Subject: ebuild-ipc: add FifoWriter class

---
 bin/ebuild-ipc.py | 79 +++++++++++++++----------------------------------------
 1 file changed, 21 insertions(+), 58 deletions(-)

diff --git a/bin/ebuild-ipc.py b/bin/ebuild-ipc.py
index 4046d8d25..d351e9454 100755
--- a/bin/ebuild-ipc.py
+++ b/bin/ebuild-ipc.py
@@ -12,7 +12,6 @@ import platform
 import signal
 import sys
 import time
-import traceback
 
 def debug_signal(signum, frame):
 	import pdb
@@ -39,9 +38,20 @@ import portage
 portage._internal_caller = True
 portage._disable_legacy_globals()
 
+from portage.util._async.ForkProcess import ForkProcess
 from portage.util._eventloop.global_event_loop import global_event_loop
 from _emerge.PipeReader import PipeReader
 
+class FifoWriter(ForkProcess):
+
+	__slots__ = ('buf', 'fifo',)
+
+	def _run(self):
+		# Atomically write the whole buffer into the fifo.
+		with open(self.fifo, 'wb', 0) as f:
+			f.write(self.buf)
+		return os.EX_OK
+
 class EbuildIpc(object):
 
 	# Timeout for each individual communication attempt (we retry
@@ -90,7 +100,7 @@ class EbuildIpc(object):
 			'ebuild-ipc: daemon process not detected\n'),
 			level=logging.ERROR, noiselevel=-1)
 
-	def _wait(self, pid, pr, msg):
+	def _run_writer(self, fifo_writer, msg):
 		"""
 		Wait on pid and return an appropriate exit code. This
 		may return unsuccessfully due to timeout if the daemon
@@ -99,49 +109,24 @@ class EbuildIpc(object):
 
 		start_time = time.time()
 
-		pipe_reader = PipeReader(input_files={"pipe_read":pr},
-			scheduler=global_event_loop())
-		pipe_reader.start()
-
-		eof = pipe_reader.poll() is not None
+		fifo_writer.start()
+		eof = fifo_writer.poll() is not None
 
 		while not eof:
-			pipe_reader._wait_loop(timeout=self._COMMUNICATE_RETRY_TIMEOUT_MS)
+			fifo_writer._wait_loop(timeout=self._COMMUNICATE_RETRY_TIMEOUT_MS)
 
-			eof = pipe_reader.poll() is not None
+			eof = fifo_writer.poll() is not None
 			if eof:
 				break
 			elif self._daemon_is_alive():
 				self._timeout_retry_msg(start_time, msg)
 			else:
-				pipe_reader.cancel()
+				fifo_writer.cancel()
 				self._no_daemon_msg()
-				try:
-					os.kill(pid, signal.SIGKILL)
-					os.waitpid(pid, 0)
-				except OSError as e:
-					portage.util.writemsg_level(
-						"ebuild-ipc: %s\n" % (e,),
-						level=logging.ERROR, noiselevel=-1)
+				fifo_writer.wait()
 				return 2
 
-		try:
-			wait_retval = os.waitpid(pid, 0)
-		except OSError as e:
-			portage.util.writemsg_level(
-				"ebuild-ipc: %s: %s\n" % (msg, e),
-				level=logging.ERROR, noiselevel=-1)
-			return 2
-
-		if not os.WIFEXITED(wait_retval[1]):
-			portage.util.writemsg_level(
-				"ebuild-ipc: %s: %s\n" % (msg,
-				portage.localization._('subprocess failure: %s') % \
-				wait_retval[1]),
-				level=logging.ERROR, noiselevel=-1)
-			return 2
-
-		return os.WEXITSTATUS(wait_retval[1])
+		return fifo_writer.wait()
 
 	def _receive_reply(self, input_fd):
 
@@ -218,31 +203,9 @@ class EbuildIpc(object):
 		# un-interrupted, while the parent handles all timeout
 		# considerations. This helps to avoid possible race conditions
 		# from interference between timeouts and blocking IO operations.
-		pr, pw = os.pipe()
-		pid = os.fork()
-
-		if pid == 0:
-			retval = 2
-			try:
-				os.close(pr)
-
-				# File streams are in unbuffered mode since we do atomic
-				# read and write of whole pickles.
-				output_file = open(self.ipc_in_fifo, 'wb', 0)
-				output_file.write(pickle.dumps(args))
-				output_file.close()
-				retval = os.EX_OK
-			except SystemExit:
-				raise
-			except:
-				traceback.print_exc()
-			finally:
-				os._exit(retval)
-
-		os.close(pw)
-
 		msg = portage.localization._('during write')
-		retval = self._wait(pid, pr, msg)
+		retval = self._run_writer(FifoWriter(buf=pickle.dumps(args),
+			fifo=self.ipc_in_fifo, scheduler=global_event_loop()), msg)
 
 		if retval != os.EX_OK:
 			portage.util.writemsg_level(
-- 
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