Mercurial > hg
view tests/test-exchange-obsmarkers-case-A2.t @ 32558:aa91085cadf3
transaction: delete callbacks after use
Before this change, localrepository instances that performed multiple
transactions would leak transaction objects. This could occur when
running `hg convert`. When running `hg convert`, the leak would be
~90 MB per 10,000 changesets as measured with the Mercurial repo itself.
The leak I tracked down involved the "validate" closure from
localrepository.transaction(). It appeared to be keeping a
reference to the original transaction via __closure__. __del__
semantics and a circular reference involving the repo object
may have also come into play.
Attempting to refactor the "validate" closure proved to be
difficult because the "tr" reference in that closure may
reference an object that isn't created until transaction.__init__
is called. And the "validate" closure is passed as an argument to
transaction.__init__. Plus there is a giant warning comment in
"validate" about how hacky it is. I did not want to venture into
the dragon den.
Anyway, we've had problems with transactions causing leaks before.
The solution then (14e683d6b273) is the same as the solution in this
patch: drop references to callbacks after they are called. This
not only breaks cycles in core Mercurial but can help break cycles
in extensions that accidentally introduce them.
While I only tracked down a leak due to self.validator, since this is
the 2nd time I've tracked down leaks due to transaction callbacks I
figure enough is enough and we should prevent the class of leak from
occurring regardless of the variable. That's why all callback variables
are now nuked.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 26 May 2017 13:27:21 -0700 |
parents | fb8c3bc27e87 |
children | eb586ed5d8ce |
line wrap: on
line source
============================================ Testing obsolescence markers push: Cases A.2 ============================================ Mercurial pushes obsolescences markers relevant to the "pushed-set", the set of all changesets that requested to be "in sync" after the push (even if they are already on both side). This test belongs to a series of tests checking such set is properly computed and applied. This does not tests "obsmarkers" discovery capabilities. Category A: simple cases TestCase 2: Two heads, only one of them pushed A.2 Two heads, only on of then pushed ===================================== .. {{{ .. ⇠○ B .. ⇠◔ | A .. |/ .. ● O .. }}} .. .. Markers exist from: .. .. * A .. * B .. .. .. Command runs: .. .. * hg push -r A .. .. Expected exchange: .. .. * chain from A .. .. Expected Exclude: .. .. * chain from B Setup ----- $ . $TESTDIR/testlib/exchange-obsmarker-util.sh initial $ setuprepos A.2 creating test repo for test case A.2 - pulldest - main - pushdest cd into `main` and proceed with env setup $ cd main $ mkcommit A $ hg debugobsolete aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa `getid 'desc(A)'` $ hg up '.~1' 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ mkcommit B created new head $ hg debugobsolete bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb `getid 'desc(B)'` $ hg log -G @ 35b183996678 (draft): B | | o f5bc6836db60 (draft): A |/ o a9bdc8b26820 (public): O $ inspect_obsmarkers obsstore content ================ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb 35b1839966785d5703a01607229eea932db42f87 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} $ cd .. $ cd .. Actual Test ----------- $ dotest A.2 A ## Running testcase A.2 # testing echange of "A" (f5bc6836db60) ## initial state # obstore: main aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb 35b1839966785d5703a01607229eea932db42f87 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest # obstore: pulldest ## pushing "A" from main to pushdest pushing to pushdest searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 1 changesets with 1 changes to 1 files remote: 1 new obsolescence markers ## post push state # obstore: main aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb 35b1839966785d5703a01607229eea932db42f87 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pulldest ## pulling "f5bc6836db60" from main into pulldest pulling from main searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files 1 new obsolescence markers (run 'hg update' to get a working copy) ## post pull state # obstore: main aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb 35b1839966785d5703a01607229eea932db42f87 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pulldest aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} $ cd ..