5 files changed, 35 insertions, 26 deletions
diff --git a/pym/_emerge/EbuildProcess.py b/pym/_emerge/EbuildProcess.py
index ce97aff0f..333ad7bd0 100644
--- a/pym/_emerge/EbuildProcess.py
+++ b/pym/_emerge/EbuildProcess.py
@@ -1,4 +1,4 @@
-# Copyright 1999-2010 Gentoo Foundation
+# Copyright 1999-2013 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 from _emerge.AbstractEbuildProcess import AbstractEbuildProcess
@@ -17,5 +17,11 @@ class EbuildProcess(AbstractEbuildProcess):
 		if actionmap is None:
 			actionmap = _spawn_actionmap(self.settings)
 
-		return _doebuild_spawn(self.phase, self.settings,
-				actionmap=actionmap, **kwargs)
+		if self._dummy_pipe_fd is not None:
+			self.settings["PORTAGE_PIPE_FD"] = str(self._dummy_pipe_fd)
+
+		try:
+			return _doebuild_spawn(self.phase, self.settings,
+					actionmap=actionmap, **kwargs)
+		finally:
+			self.settings.pop("PORTAGE_PIPE_FD", None)
diff --git a/pym/_emerge/EbuildSpawnProcess.py b/pym/_emerge/EbuildSpawnProcess.py
index e1f682a66..26d26fc77 100644
--- a/pym/_emerge/EbuildSpawnProcess.py
+++ b/pym/_emerge/EbuildSpawnProcess.py
@@ -1,4 +1,4 @@
-# Copyright 2010 Gentoo Foundation
+# Copyright 2010-2013 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 from _emerge.AbstractEbuildProcess import AbstractEbuildProcess
@@ -13,4 +13,10 @@ class EbuildSpawnProcess(AbstractEbuildProcess):
 	__slots__ = ('fakeroot_state', 'spawn_func')
 
 	def _spawn(self, args, **kwargs):
-		return self.spawn_func(args, env=self.settings.environ(), **kwargs)
+
+		env = self.settings.environ()
+
+		if self._dummy_pipe_fd is not None:
+			env["PORTAGE_PIPE_FD"] = str(self._dummy_pipe_fd)
+
+		return self.spawn_func(args, env=env, **kwargs)
diff --git a/pym/_emerge/MiscFunctionsProcess.py b/pym/_emerge/MiscFunctionsProcess.py
index afa44fb2a..bada79d86 100644
--- a/pym/_emerge/MiscFunctionsProcess.py
+++ b/pym/_emerge/MiscFunctionsProcess.py
@@ -1,4 +1,4 @@
-# Copyright 1999-2011 Gentoo Foundation
+# Copyright 1999-2013 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 from _emerge.AbstractEbuildProcess import AbstractEbuildProcess
@@ -29,6 +29,10 @@ class MiscFunctionsProcess(AbstractEbuildProcess):
 		AbstractEbuildProcess._start(self)
 
 	def _spawn(self, args, **kwargs):
+
+		if self._dummy_pipe_fd is not None:
+			self.settings["PORTAGE_PIPE_FD"] = str(self._dummy_pipe_fd)
+
 		# Temporarily unset EBUILD_PHASE so that bashrc code doesn't
 		# think this is a real phase.
 		phase_backup = self.settings.pop("EBUILD_PHASE", None)
@@ -37,3 +41,4 @@ class MiscFunctionsProcess(AbstractEbuildProcess):
 		finally:
 			if phase_backup is not None:
 				self.settings["EBUILD_PHASE"] = phase_backup
+			self.settings.pop("PORTAGE_PIPE_FD", None)
diff --git a/pym/_emerge/SpawnProcess.py b/pym/_emerge/SpawnProcess.py
index 9c754add5..ebba7d3d4 100644
--- a/pym/_emerge/SpawnProcess.py
+++ b/pym/_emerge/SpawnProcess.py
@@ -70,23 +70,20 @@ class SpawnProcess(SubProcess):
 
 		fd_pipes_orig = fd_pipes.copy()
 
-		if log_file_path is not None:
+		if log_file_path is not None or self.background:
 			fd_pipes[1] = slave_fd
 			fd_pipes[2] = slave_fd
 
 		else:
-			# Create a dummy pipe so the scheduler can monitor
-			# the process from inside a poll() loop. Ensure that
-			# it doesn't interfere with a random fd that's already
-			# in fd_pipes though (as least FileDigester can pass
-			# in a random fd returned from os.pipe()).
-			unique_dummy_fd = self._dummy_pipe_fd
-			while unique_dummy_fd in fd_pipes:
-				unique_dummy_fd += 1
-			fd_pipes[unique_dummy_fd] = slave_fd
-			if self.background:
-				fd_pipes[1] = slave_fd
-				fd_pipes[2] = slave_fd
+			# Create a dummy pipe that PipeLogger uses to efficiently
+			# monitors for process exit by listening for the EOF event.
+			# Re-use of the allocated fd number for the key in fd_pipes
+			# guarantees that the keys will not collide for similarly
+			# allocated pipes which are used by callers such as
+			# FileDigester and MergeProcess. See the _setup_pipes
+			# docstring for more benefits of this allocation approach.
+			self._dummy_pipe_fd = slave_fd
+			fd_pipes[slave_fd] = slave_fd
 
 		kwargs = {}
 		for k in self._spawn_kwarg_names:
diff --git a/pym/_emerge/SubProcess.py b/pym/_emerge/SubProcess.py
index 92cbc27ab..4ccf9164f 100644
--- a/pym/_emerge/SubProcess.py
+++ b/pym/_emerge/SubProcess.py
@@ -1,4 +1,4 @@
-# Copyright 1999-2012 Gentoo Foundation
+# Copyright 1999-2013 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 from portage import os
@@ -9,12 +9,7 @@ import errno
 class SubProcess(AbstractPollTask):
 
 	__slots__ = ("pid",) + \
-		("_files", "_reg_id")
-
-	# A file descriptor is required for the scheduler to monitor changes from
-	# inside a poll() loop. When logging is not enabled, create a pipe just to
-	# serve this purpose alone.
-	_dummy_pipe_fd = 9
+		("_dummy_pipe_fd", "_files", "_reg_id")
 
 	# This is how much time we allow for waitpid to succeed after
 	# we've sent a kill signal to our subprocess.