Enhance the find_smallest_cycle function to prioritize its search so that it will minimize the use of installed packages to break cycles. When installed packages must be used to break cycles, it will now prefer to do this for runtime dependencies over buildtime dependencies, since it's preferable to build against latest versions of buildtime dependencies whenever possible. This should solve some cases of bug 199856 which have been triggered by unsafe reliance on installed packages to break cycles.
The included unit test case demonstrates correct merge order for a dependency calculation involving 6 independent cycles. This test case fails with the master branch, due to a buildtime dependency cycle of 3 packages being merged earlier than cycles of 2 packages. We can generalize this to say that the master branch may use an installed package to break an arbitrarily sized cycle in a somewhat random location, even though that cycle may be composed of smaller independent cycles which would be safer to break individually. Bug: https://bugs.gentoo.org/754903 Signed-off-by: Zac Medico <zmed...@gentoo.org> --- [PATCH v2] * Add a unit test case which demonstrates a significant flaw in the master branch. * Sort nodes in find_smallest_cycle, for deterministic results. lib/_emerge/DepPriorityNormalRange.py | 2 + lib/_emerge/DepPrioritySatisfiedRange.py | 52 ++++++++++--------- lib/_emerge/depgraph.py | 43 +++++++++------ .../tests/resolver/test_merge_order.py | 10 ++++ 4 files changed, 66 insertions(+), 41 deletions(-) diff --git a/lib/_emerge/DepPriorityNormalRange.py b/lib/_emerge/DepPriorityNormalRange.py index 5f3f3da70..10f205a3b 100644 --- a/lib/_emerge/DepPriorityNormalRange.py +++ b/lib/_emerge/DepPriorityNormalRange.py @@ -14,6 +14,7 @@ class DepPriorityNormalRange: """ MEDIUM = 3 MEDIUM_SOFT = 2 + MEDIUM_POST = 2 SOFT = 1 NONE = 0 @@ -37,6 +38,7 @@ class DepPriorityNormalRange: ignore_medium = _ignore_runtime ignore_medium_soft = _ignore_runtime_post + ignore_medium_post = _ignore_runtime_post ignore_soft = _ignore_optional DepPriorityNormalRange.ignore_priority = ( diff --git a/lib/_emerge/DepPrioritySatisfiedRange.py b/lib/_emerge/DepPrioritySatisfiedRange.py index e056e676f..df2439f1f 100644 --- a/lib/_emerge/DepPrioritySatisfiedRange.py +++ b/lib/_emerge/DepPrioritySatisfiedRange.py @@ -8,17 +8,18 @@ class DepPrioritySatisfiedRange: not satisfied and buildtime HARD not satisfied and runtime 7 MEDIUM - not satisfied and runtime_post 6 MEDIUM_SOFT - satisfied and buildtime_slot_op 5 SOFT - satisfied and buildtime 4 SOFT - satisfied and runtime 3 SOFT - satisfied and runtime_post 2 SOFT + satisfied and buildtime_slot_op 6 MEDIUM_SOFT + satisfied and buildtime 5 MEDIUM_SOFT + satisfied and runtime 4 MEDIUM_SOFT + runtime_post 3 MEDIUM_POST + satisfied and runtime_post 2 MEDIUM_POST optional 1 SOFT (none of the above) 0 NONE """ MEDIUM = 7 MEDIUM_SOFT = 6 - SOFT = 5 + MEDIUM_POST = 3 + SOFT = 1 NONE = 0 @classmethod @@ -37,15 +38,23 @@ class DepPrioritySatisfiedRange: return False return bool(priority.runtime_post) + @classmethod + def _ignore_runtime_post(cls, priority): + if priority.__class__ is not DepPriority: + return False + return bool(priority.optional or priority.runtime_post) + @classmethod def _ignore_satisfied_runtime(cls, priority): if priority.__class__ is not DepPriority: return False if priority.optional: return True - if not priority.satisfied: + if priority.buildtime: return False - return not priority.buildtime + if not priority.runtime: + return True + return bool(priority.satisfied) @classmethod def _ignore_satisfied_buildtime(cls, priority): @@ -61,37 +70,32 @@ class DepPrioritySatisfiedRange: def _ignore_satisfied_buildtime_slot_op(cls, priority): if priority.__class__ is not DepPriority: return False - return bool(priority.optional or \ - priority.satisfied) - - @classmethod - def _ignore_runtime_post(cls, priority): - if priority.__class__ is not DepPriority: - return False - return bool(priority.optional or \ - priority.satisfied or \ - priority.runtime_post) + if priority.optional: + return True + if priority.satisfied: + return True + return not priority.buildtime and not priority.runtime @classmethod def _ignore_runtime(cls, priority): if priority.__class__ is not DepPriority: return False - return bool(priority.satisfied or \ - priority.optional or \ - not priority.buildtime) + return bool(priority.optional or + priority.satisfied or priority.runtime) ignore_medium = _ignore_runtime - ignore_medium_soft = _ignore_runtime_post - ignore_soft = _ignore_satisfied_buildtime + ignore_medium_soft = _ignore_satisfied_buildtime_slot_op + ignore_medium_post = _ignore_runtime_post + ignore_soft = _ignore_optional DepPrioritySatisfiedRange.ignore_priority = ( None, DepPrioritySatisfiedRange._ignore_optional, DepPrioritySatisfiedRange._ignore_satisfied_runtime_post, + DepPrioritySatisfiedRange._ignore_runtime_post, DepPrioritySatisfiedRange._ignore_satisfied_runtime, DepPrioritySatisfiedRange._ignore_satisfied_buildtime, DepPrioritySatisfiedRange._ignore_satisfied_buildtime_slot_op, - DepPrioritySatisfiedRange._ignore_runtime_post, DepPrioritySatisfiedRange._ignore_runtime ) diff --git a/lib/_emerge/depgraph.py b/lib/_emerge/depgraph.py index 6aaacfe44..af26ecd93 100644 --- a/lib/_emerge/depgraph.py +++ b/lib/_emerge/depgraph.py @@ -7905,7 +7905,7 @@ class depgraph: if check_asap_parent: for node in nodes: parents = mygraph.parent_nodes(node, - ignore_priority=DepPrioritySatisfiedRange.ignore_soft) + ignore_priority=DepPrioritySatisfiedRange.ignore_medium_soft) if any(x in asap_nodes for x in parents): selected_nodes = [node] break @@ -7921,7 +7921,7 @@ class depgraph: if not selected_nodes: - def find_smallest_cycle(mergeable_nodes, priority_ranges): + def find_smallest_cycle(mergeable_nodes, local_priority_range): if prefer_asap and asap_nodes: nodes = asap_nodes else: @@ -7938,18 +7938,27 @@ class depgraph: # these smaller independent cycles. smallest_cycle = None ignore_priority = None - for node in nodes: - if not mygraph.parent_nodes(node): - continue - for local_priority_range in priority_ranges: + + # Sort nodes for deterministic results. + nodes = sorted(nodes) + for priority in (local_priority_range.ignore_priority[i] for i in range( + local_priority_range.MEDIUM_POST, + local_priority_range.MEDIUM_SOFT + 1)): + for node in nodes: + if not mygraph.parent_nodes(node): + continue selected_nodes = set() - if gather_deps(local_priority_range.ignore_medium_soft, + if gather_deps(priority, mergeable_nodes, selected_nodes, node): if smallest_cycle is None or \ len(selected_nodes) < len(smallest_cycle): smallest_cycle = selected_nodes - ignore_priority = local_priority_range.ignore_medium_soft - break + ignore_priority = priority + + # Exit this loop with the lowest possible priority, which + # minimizes the use of installed packages to break cycles. + if smallest_cycle is not None: + break return smallest_cycle, ignore_priority @@ -7963,7 +7972,7 @@ class depgraph: for local_priority_range in priority_ranges: mergeable_nodes = set(get_nodes(ignore_priority=local_priority_range.ignore_medium)) if mergeable_nodes: - selected_nodes, ignore_priority = find_smallest_cycle(mergeable_nodes, priority_ranges) + selected_nodes, ignore_priority = find_smallest_cycle(mergeable_nodes, local_priority_range) if selected_nodes: break @@ -8001,19 +8010,19 @@ class depgraph: (selected_nodes[0],), noiselevel=-1) if selected_nodes and ignore_priority is not None: - # Try to merge ignored medium_soft deps as soon as possible + # Try to merge ignored medium_post deps as soon as possible # if they're not satisfied by installed packages. for node in selected_nodes: children = set(mygraph.child_nodes(node)) soft = children.difference( - mygraph.child_nodes(node, - ignore_priority=DepPrioritySatisfiedRange.ignore_soft)) - medium_soft = children.difference( mygraph.child_nodes(node, ignore_priority = \ - DepPrioritySatisfiedRange.ignore_medium_soft)) - medium_soft -= soft - for child in medium_soft: + DepPrioritySatisfiedRange.ignore_soft)) + medium_post = children.difference( + mygraph.child_nodes(node, + ignore_priority=DepPrioritySatisfiedRange.ignore_medium_post)) + medium_post -= soft + for child in medium_post: if child in selected_nodes: continue if child in asap_nodes: diff --git a/lib/portage/tests/resolver/test_merge_order.py b/lib/portage/tests/resolver/test_merge_order.py index 0003cd7d8..f81fd2f6f 100644 --- a/lib/portage/tests/resolver/test_merge_order.py +++ b/lib/portage/tests/resolver/test_merge_order.py @@ -490,6 +490,16 @@ class MergeOrderTestCase(TestCase): success=True, all_permutations = True, mergelist = ['x11-base/xorg-server-1.14.1', 'media-libs/mesa-9.1.3']), + # Test prioritization of the find_smallest_cycle function, which should + # minimize the use of installed packages to break cycles. If installed + # packages must be used to break cycles, then it should prefer to do this + # for runtime dependencies over buildtime dependencies. If a package needs + # to be uninstalled in order to solve a blocker, then it should prefer to + # do this before it uses an installed package to break a cycle. + ResolverPlaygroundTestCase( + ["app-misc/some-app-a", "app-misc/some-app-b", "app-misc/some-app-c", "app-misc/circ-buildtime-a", "app-misc/blocker-buildtime-unbuilt-a", "media-libs/mesa", "x11-base/xorg-server", "app-misc/circ-direct-a", "app-misc/circ-direct-b", "app-misc/circ-satisfied-a", "app-misc/circ-satisfied-b", "app-misc/circ-satisfied-c"], + success = True, + mergelist = ['app-misc/circ-post-runtime-a-1', 'app-misc/circ-post-runtime-c-1', 'app-misc/circ-post-runtime-b-1', 'app-misc/some-app-b-1', 'app-misc/circ-runtime-a-1', 'app-misc/circ-runtime-b-1', 'app-misc/circ-runtime-c-1', 'app-misc/some-app-a-1', 'app-misc/blocker-buildtime-unbuilt-a-1', '[uninstall]app-misc/installed-blocker-a-1', '!app-misc/installed-blocker-a', 'app-misc/circ-direct-a-1', 'app-misc/circ-direct-b-1', 'x11-base/xorg-server-1.14.1', 'media-libs/mesa-9.1.3', 'app-misc/circ-buildtime-a-1', 'app-misc/circ-buildtime-b-1', 'app-misc/circ-buildtime-c-1', 'app-misc/some-app-c-1', 'app-misc/circ-satisfied-a-1', 'app-misc/circ-satisfied-b-1', 'app-misc/circ-satisfied-c-1']), ) playground = ResolverPlayground(ebuilds=ebuilds, installed=installed) -- 2.26.2
