cext: fix memory leak in phases computation Without this a buffer whose size in bytes is the number of changesets in the repository is leaked each time the repository is opened and changeset phases are computed. Impact: the current code in hgwebdir creates a new `localrepository` instance for each HTTP request. Since any pull or push is made of several requests, a team of 100 people can easily produce thousands of such requests per day. Being a low-level malloc, this leak can't be seen with the gc module and tools relying on that, but was spotted by valgrind immediately. Reproduction ------------ for i in range(cl_args.iterations): repo = hg.repository(baseui, repo_path) rev = repo.revs(rev).first() ctx = repo[rev] del ctx del repo # avoid any pollution by other type of leak # (that should be fixed in 5.8) repoview._filteredrepotypes.clear() gc.collect() Measurements ------------ Resident Set Size (RSS), taken on a clone of mozilla-central for performance analysis (440 000 changesets). before: 5.8+hg19.5ac0f2a8ba72 1000 iterations: 1606MB 5.8+hg19.5ac0f2a8ba72 10000 iterations: 5723MB after: 5.8+hg20.e2084d39e145 1000 iterations: 555MB 5.8+hg20.e2084d39e145 10000 iterations: 555MB (double checked, not a copy/paste error) (e2084d39e14 is the present changeset, before amendment of the message to add the measurements)

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  $ hg init t

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  $ cd t

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  $ echo This is file a1 > a

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  $ hg add a

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  $ hg commit -m "commit #0"

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  $ echo This is file b1 > b

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  $ hg add b

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  $ hg commit -m "commit #1"

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  $ rm b

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  $ hg update 0

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  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

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  $ echo This is file b2 > b

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  $ hg add b

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  $ hg commit -m "commit #2"

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  created new head

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  $ cd ..; rm -r t

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  $ mkdir t

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  $ cd t

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  $ hg init

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  $ echo This is file a1 > a

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  $ hg add a

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  $ hg commit -m "commit #0"

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  $ echo This is file b1 > b

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  $ hg add b

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  $ hg commit -m "commit #1"

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  $ rm b

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  $ hg update 0

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  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

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  $ echo This is file b2 > b

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  $ hg commit -A -m "commit #2"

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  adding b

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  created new head

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  $ cd ..; rm -r t

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  $ hg init t

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  $ cd t

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  $ echo This is file a1 > a

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  $ hg add a

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  $ hg commit -m "commit #0"

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  $ echo This is file b1 > b

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  $ hg add b

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  $ hg commit -m "commit #1"

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  $ rm b

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  $ hg remove b

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  $ hg update 0

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  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

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  $ echo This is file b2 > b

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  $ hg commit -A -m "commit #2"

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  adding b

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  created new head

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  $ hg merge 'wdir()'

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  abort: merging with the working copy has no effect

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  [10]

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  $ cd ..