[gentoo-commits] gentoo-x86 commit in eclass: ChangeLog multibuild.eclass

[Michal Gorny (mgorny)]

mgorny      13/05/23 20:19:29

  Modified:             ChangeLog multibuild.eclass
  Log:
  Use portable locking code from Fabian Groffen. Bug #466554.

Revision  Changes    Path
1.836                eclass/ChangeLog

file : http://sources.gentoo.org/viewvc.cgi/gentoo-x86/eclass/ChangeLog?rev=1.836&view=markup
plain: http://sources.gentoo.org/viewvc.cgi/gentoo-x86/eclass/ChangeLog?rev=1.836&content-type=text/plain
diff : http://sources.gentoo.org/viewvc.cgi/gentoo-x86/eclass/ChangeLog?r1=1.835&r2=1.836

Index: ChangeLog
===================================================================
RCS file: /var/cvsroot/gentoo-x86/eclass/ChangeLog,v
retrieving revision 1.835
retrieving revision 1.836
diff -u -r1.835 -r1.836
--- ChangeLog	22 May 2013 05:10:29 -0000	1.835
+++ ChangeLog	23 May 2013 20:19:28 -0000	1.836
@@ -1,6 +1,9 @@
 # ChangeLog for eclass directory
 # Copyright 1999-2013 Gentoo Foundation; Distributed under the GPL v2
-# $Header: /var/cvsroot/gentoo-x86/eclass/ChangeLog,v 1.835 2013/05/22 05:10:29 mgorny Exp $
+# $Header: /var/cvsroot/gentoo-x86/eclass/ChangeLog,v 1.836 2013/05/23 20:19:28 mgorny Exp $
+
+  23 May 2013; Michał Górny <mgorny@g.o> multibuild.eclass:
+  Use portable locking code from Fabian Groffen. Bug #466554.
 
   22 May 2013; Michał Górny <mgorny@g.o> eutils.eclass:
   Fix the libtool check, bug #470938.



1.10                 eclass/multibuild.eclass

file : http://sources.gentoo.org/viewvc.cgi/gentoo-x86/eclass/multibuild.eclass?rev=1.10&view=markup
plain: http://sources.gentoo.org/viewvc.cgi/gentoo-x86/eclass/multibuild.eclass?rev=1.10&content-type=text/plain
diff : http://sources.gentoo.org/viewvc.cgi/gentoo-x86/eclass/multibuild.eclass?r1=1.9&r2=1.10

Index: multibuild.eclass
===================================================================
RCS file: /var/cvsroot/gentoo-x86/eclass/multibuild.eclass,v
retrieving revision 1.9
retrieving revision 1.10
diff -u -r1.9 -r1.10
--- multibuild.eclass	1 Apr 2013 09:17:53 -0000	1.9
+++ multibuild.eclass	23 May 2013 20:19:28 -0000	1.10
@@ -1,6 +1,6 @@
 # Copyright 1999-2013 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
-# $Header: /var/cvsroot/gentoo-x86/eclass/multibuild.eclass,v 1.9 2013/04/01 09:17:53 mgorny Exp $
+# $Header: /var/cvsroot/gentoo-x86/eclass/multibuild.eclass,v 1.10 2013/05/23 20:19:28 mgorny Exp $
 
 # @ECLASS: multibuild
 # @MAINTAINER:
@@ -251,38 +251,39 @@
 	local src=${1}
 	local dest=${2}
 
-	local lockfile=${T}/multibuild_merge_lock
+	local lockfile=${T}/.multibuild_merge_lock
+	local lockfile_l=${lockfile}.${$}
 	local ret
 
+	# Lock the install tree for merge. The touch+ln method ensures race
+	# condition-free locking with maximum portability.
+	touch "${lockfile_l}" || die
+	until ln "${lockfile_l}" "${lockfile}" &>/dev/null; do
+		sleep 1
+	done
+	rm "${lockfile_l}" || die
+
 	if use userland_BSD; then
-		# Locking is done by 'lockf' which can wrap a command.
 		# 'cp -a -n' is broken:
 		# http://www.freebsd.org/cgi/query-pr.cgi?pr=174489
 		# using tar instead which is universal but terribly slow.
 
 		tar -C "${src}" -f - -c . \
-			| lockf "${lockfile}" tar -x -f - -C "${dest}"
+			| tar -x -f - -C "${dest}"
 		[[ ${PIPESTATUS[*]} == '0 0' ]]
 		ret=${?}
 	elif use userland_GNU; then
-		# GNU has 'flock' which can't wrap commands but can lock
-		# a fd which is good enough for us.
-		# and cp works with '-a -n'.
-
-		local lock_fd
-		redirect_alloc_fd lock_fd "${lockfile}" '>>'
-		flock ${lock_fd}
+		# cp works with '-a -n'.
 
 		cp -a -l -n "${src}"/. "${dest}"/
 		ret=${?}
-
-		# Close the lock file when we are done with it.
-		# Prevents deadlock if we aren't in a subshell.
-		eval "exec ${lock_fd}>&-"
 	else
 		die "Unsupported userland (${USERLAND}), please report."
 	fi
 
+	# Remove the lock.
+	rm "${lockfile}" || die
+
 	if [[ ${ret} -ne 0 ]]; then
 		die "${MULTIBUILD_VARIANT:-(unknown)}: merging image failed."
 	fi