Add FEATURES=parallel-install for finer locks.

4 files changed, 20 insertions, 3 deletions

diff --git a/man/make.conf.5 b/man/make.conf.5
index 389bab1db..067f7065a 100644
--- a/man/make.conf.5
+++ b/man/make.conf.5
@@ -267,7 +267,7 @@ when a problem arises (normally due to a crash or disconnect).
 .TP
 .B ebuild\-locks
 Use locks to ensure that unsandboxed ebuild phases never execute
-concurrently.
+concurrently. Also see \fIparallel\-install\fR.
 .TP
 .B fakeroot
 Enable fakeroot for the install and package phases when a non-root user runs
@@ -373,6 +373,11 @@ Fetch in the background while compiling. Run
 `tail \-f /var/log/emerge\-fetch.log` in a
 terminal to view parallel-fetch progress.
 .TP
+.B parallel\-install
+Use finer\-grained locks when installing packages, allowing for greater
+parallelization. For additional parallelization, disable
+\fIebuild\-locks\fR.
+.TP
 .B parse\-eapi\-ebuild\-head
 Parse \fBEAPI\fR from the head of the ebuild (first 30 lines). This feature
 is only intended for experimental purposes and should not be enabled under
diff --git a/pym/_emerge/Scheduler.py b/pym/_emerge/Scheduler.py
index fc69d48ae..182ad8771 100644
--- a/pym/_emerge/Scheduler.py
+++ b/pym/_emerge/Scheduler.py
@@ -387,7 +387,8 @@ class Scheduler(PollScheduler):
 	def _set_max_jobs(self, max_jobs):
 		self._max_jobs = max_jobs
 		self._task_queues.jobs.max_jobs = max_jobs
-		self._task_queues.merge.max_jobs = max_jobs
+		if "parallel-install" in self.settings.features:
+			self._task_queues.merge.max_jobs = max_jobs
 
 	def _background_mode(self):
 		"""
diff --git a/pym/portage/const.py b/pym/portage/const.py
index 0bd56b20f..98f3dac6d 100644
--- a/pym/portage/const.py
+++ b/pym/portage/const.py
@@ -93,7 +93,8 @@ SUPPORTED_FEATURES       = frozenset([
                            "installsources", "keeptemp", "keepwork", "fixlafiles", "lmirror",
                            "metadata-transfer", "mirror", "multilib-strict", "news",
                            "noauto", "noclean", "nodoc", "noinfo", "noman",
-                           "nostrip", "notitles", "parallel-fetch", "parse-eapi-ebuild-head",
+                           "nostrip", "notitles", "parallel-fetch", "parallel-install",
+                           "parse-eapi-ebuild-head",
                            "prelink-checksums", "preserve-libs",
                            "protect-owned", "python-trace", "sandbox",
                            "selinux", "sesandbox", "severe", "sfperms",
diff --git a/pym/portage/dbapi/vartree.py b/pym/portage/dbapi/vartree.py
index 2708e4307..92c467d43 100644
--- a/pym/portage/dbapi/vartree.py
+++ b/pym/portage/dbapi/vartree.py
@@ -3914,6 +3914,9 @@ class dblink(object):
 		"""
 		myroot = None
 		retval = -1
+		parallel_install = "parallel-install" in self.settings.features
+		if not parallel_install:
+			self.lockdb()
 		self.vartree.dbapi._bump_mtime(self.mycpv)
 		try:
 			retval = self.treewalk(mergeroot, myroot, inforoot, myebuild,
@@ -3966,6 +3969,8 @@ class dblink(object):
 			else:
 				self.vartree.dbapi._linkmap._clear_cache()
 			self.vartree.dbapi._bump_mtime(self.mycpv)
+			if not parallel_install:
+				self.unlockdb()
 		return retval
 
 	def getstring(self,name):
@@ -4066,6 +4071,9 @@ def unmerge(cat, pkg, myroot=None, settings=None,
 	mylink = dblink(cat, pkg, settings=settings, treetype="vartree",
 		vartree=vartree, scheduler=scheduler)
 	vartree = mylink.vartree
+	parallel_install = "parallel-install" in self.settings.features
+	if not parallel_install:
+		self.lockdb()
 	try:
 		if mylink.exists():
 			retval = mylink.unmerge(ldpath_mtimes=ldpath_mtimes)
@@ -4083,6 +4091,8 @@ def unmerge(cat, pkg, myroot=None, settings=None,
 			pass
 		else:
 			vartree.dbapi._linkmap._clear_cache()
+		if not parallel_install:
+			self.unlockdb()
 
 def write_contents(contents, root, f):
 	"""