From: Zac Medico <zmedico@gentoo.org>
Date: Sat, 14 May 2011 23:53:35 +0000 (-0700)
Subject: counter_tick_core: don't lock if parallel-install
X-Git-Tag: v2.2.0_alpha34~48
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=461564ae94ff936918eeaa18493bc1da3846796f;p=portage.git

counter_tick_core: don't lock if parallel-install

Hopefully this avoids the following exception:

  File "/usr/lib/portage/pym/portage/locks.py", line 138, in lockfile
    fcntl.lockf(myfd, fcntl.LOCK_EX)
IOError: [Errno 35] Resource deadlock avoided
---

diff --git a/pym/portage/dbapi/vartree.py b/pym/portage/dbapi/vartree.py
index fca590a0b..802253afc 100644
--- a/pym/portage/dbapi/vartree.py
+++ b/pym/portage/dbapi/vartree.py
@@ -789,7 +789,15 @@ class vardbapi(dbapi):
 		"""
 		myroot = None
 		mycpv = None
-		self.lock()
+		locked_vdb = False
+		if "parallel-install" not in self.settings.features:
+			# If parallel-install is enabled, it's unsafe to
+			# lock the vdb here since the portage.locks module
+			# does not behave as desired if we try to lock the
+			# same file multiple times concurrently from the
+			# same process.
+			self.lock()
+			locked_vdb = True
 		try:
 			counter = self.get_counter_tick_core() - 1
 			if self._cached_counter != counter:
@@ -803,7 +811,8 @@ class vardbapi(dbapi):
 					write_atomic(self._counter_path, str(counter))
 				self._cached_counter = counter
 		finally:
-			self.unlock()
+			if locked_vdb:
+				self.unlock()
 
 		return counter