bigfile/tests/test_filezodb.py ........W: testdb: teardown: <Connection at 7f8fe2b43b90> left not closed by test code; opened by:
  ...
  File "/home/kirr/src/wendelin/wendelin.core/bigfile/tests/test_filezodb.py", line 754, in test_bigfile_zblk1_zdata_reuse
    _test_bigfile_zblk1_zdata_reuse()
  File "/home/kirr/src/wendelin/wendelin.core/bigfile/tests/test_filezodb.py", line 759, in _test_bigfile_zblk1_zdata_reuse
    root = dbopen()
  File "/home/kirr/src/wendelin/wendelin.core/bigfile/tests/test_filezodb.py", line 47, in dbopen
    return testdb.dbopen()
  File "/home/kirr/src/wendelin/wendelin.core/lib/testing.py", line 188, in dbopen
    self.connv.append( (weakref.ref(conn), ''.join(traceback.format_stack())) )

lib/tests/test_zodb.py .W: testdb: teardown: <Connection at 7f8fe26f13d0> left not closed by test code; opened by:
  ...
  File "/home/kirr/src/wendelin/wendelin.core/lib/tests/test_zodb.py", line 49, in test_deactivate_btree
    root = dbopen()
  File "/home/kirr/src/wendelin/wendelin.core/lib/tests/test_zodb.py", line 30, in dbopen
    return testdb.dbopen()
  File "/home/kirr/src/wendelin/wendelin.core/lib/testing.py", line 188, in dbopen
    self.connv.append( (weakref.ref(conn), ''.join(traceback.format_stack())) )

If a test forgets to explicitly close ZODB connection it was using, this
connection stays alive in transaction synchronizers (it is a weakset),
and continues to be used on e.g. transaction.commit() when all
synchronizers are invoked. This could lead to crashes like below when
underlying ZODB storage was closed by test module teardown and testing
moved on to another test module:

    $ WENDELIN_CORE_TEST_DB="<neo>" py.test  bigfile/tests/test_filezodb.py::test_bigfile_zblk1_zdata_reuse lib/tests/test_zodb.py
    ======= test session starts ========
    platform linux2 -- Python 2.7.14+, pytest-3.5.0, py-1.5.3, pluggy-0.6.0
    rootdir: /home/kirr/src/wendelin/wendelin.core, inifile:
    collected 2 items

    bigfile/tests/test_filezodb.py .                                     [ 50%]
    lib/tests/test_zodb.py F                                             [100%]

    ______ test_deactivate_btree _______

        def test_deactivate_btree():
            root = dbopen()
            # init btree with many leaf nodes
            leafv = []
            root['btree'] = B = IOBTree()
            for i in range(10000):
                B[i] = xi = XInt(i)
                leafv.append(xi)
    >       transaction.commit()

    lib/tests/test_zodb.py:56:
    _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
    ../venv/z5/local/lib/python2.7/site-packages/transaction/_manager.py:131: in commit
        return self.get().commit()
    ../venv/z5/local/lib/python2.7/site-packages/transaction/_transaction.py:316: in commit
        self._synchronizers.map(lambda s: s.afterCompletion(self))
    ../venv/z5/local/lib/python2.7/site-packages/transaction/weakset.py:62: in map
        f(elt)
    ../venv/z5/local/lib/python2.7/site-packages/transaction/_transaction.py:316: in <lambda>
        self._synchronizers.map(lambda s: s.afterCompletion(self))
    ../venv/z5/local/lib/python2.7/site-packages/ZODB/Connection.py:757: in afterCompletion
        self.newTransaction(transaction, False)
    ../venv/z5/local/lib/python2.7/site-packages/ZODB/Connection.py:737: in newTransaction
        invalidated = self._storage.poll_invalidations()
    ../venv/z5/local/lib/python2.7/site-packages/ZODB/mvccadapter.py:131: in poll_invalidations
        self._start = p64(u64(self._storage.lastTransaction()) + 1)
    _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

    self = <neo.client.Storage.Storage object at 0x7ffa1be8d410>

        def lastTransaction(self):
            # Used in ZODB unit tests
    >       return self.app.last_tid
    E       AttributeError: 'NoneType' object has no attribute 'last_tid'

    ../../neo/src/lab.nexedi.com/kirr/neo/neo/client/Storage.py:181: AttributeError

where NEO's Storage.app is None because the storage was closed.

----

To avoid such kind of failures make sure TestDB.teardown() always closes
all ZODB connections that were ever opened via TestDB.dbopen().

Add a warning about such force-closing with information about corresponding
connection and code place that created it, so that it is easy to
understand which test needs a fix.

/suggested-by @jm

- start testing NEO with ZODB4 and ZODB5. ZODB4-*-NEO works while
  ZODB5-*-NEO currently fails [1].
- update NumPy to latest releases.
- update Python 3 to latest releases.

Since 7fc4ec66 (tests: Allow to test with ZEO & NEO ZODB storages) we
can run the tests with either FileStorage, ZEO or NEO. But ZEO test
adapter started to fail with ZEO5:

	self = <wendelin.lib.testing.TestDB_ZEO object at 0x7f1feb5091d0>

	    def setup(self):
	        port  = self.zeo_forker.get_port()
	        zconf = self.zeo_forker.ZEOConfig(('', port))
	        self.addr, self.adminaddr, self.pid, self.path = \
	>               self.zeo_forker.start_zeo_server(zeo_conf=zconf, port=port)
	E       ValueError: need more than 2 values to unpack

This is because in ZEO5 forker.start_zeo_server() was reworked to return only
addr and stop closure instead of returning all details and relying on caller to
implement stop itself.

Adapt the test to detect ZEO5 and use new calling convention.

With ZConfig==3.2.0 (released 2017-06-22) ZEO started to get file names
as unicode, which eventually breaks on assert in ZODB3.FileStorage code:

    Traceback (most recent call last):
      File "/home/kirr/src/wendelin/r/work/venv/local/lib/python2.7/site-packages/ZEO/tests/zeoserver.py", line 215, in <module>
        main()
      File "/home/kirr/src/wendelin/r/work/venv/local/lib/python2.7/site-packages/ZEO/tests/zeoserver.py", line 188, in main
        server = ZEO.runzeo.create_server({"1": storage}, zo)
      File "/home/kirr/src/wendelin/r/work/venv/local/lib/python2.7/site-packages/ZEO/runzeo.py", line 366, in create_server
        auth_realm = options.auth_realm,
      File "/home/kirr/src/wendelin/r/work/venv/local/lib/python2.7/site-packages/ZEO/StorageServer.py", line 890, in __init__
        self._setup_invq(name, storage)
      File "/home/kirr/src/wendelin/r/work/venv/local/lib/python2.7/site-packages/ZEO/StorageServer.py", line 928, in _setup_invq
        self.invq[name] = list(lastInvalidations(self.invq_bound))
      File "/home/kirr/src/wendelin/r/work/venv/local/lib/python2.7/site-packages/ZODB/FileStorage/FileStorage.py", line 1238, in lastInvalidations
        for trans in FileIterator(self._file_name, pos=pos)]
      File "/home/kirr/src/wendelin/r/work/venv/local/lib/python2.7/site-packages/ZODB/FileStorage/FileStorage.py", line 1640, in __init__
        assert isinstance(filename, str), `filename`
    AssertionError: u'/home/kirr/src/wendelin/r/work/wendelin.core/Data.fs'

-> So for ZODB3 pin ZConfig to ZConfig <3.2.0 which is known to work with ZODB3.

ArrayRef is a reference to NumPy array.

The reference is represented by root array object and instructions how to
create original array as some view of the root.

Such reference could be useful in situations where one needs to pass arrays
between processes and instead of copying array data, leverage the fact that
top-level array, for example ZBigArray, is already persisted separately, and
only send small amount of information referencing data in question.

Use `ArrayRef(array)` to create reference to an ndarray.

Use `.deref()` to convert ArrayRef to pointed array object.

NOTE

don't send ArrayRef unconditionally - for example when array object is
small regular ndarray with also regular, but big, root ndarray, sending
ArrayRef will send whole data for root object, not for small leaf.

Sending ArrayRef only makes sense when root object is known to be already
persisted by other means, for example something like below in ZODB context:

```python
  aref = ArrayRef(a)
  if isinstance(aref.root, Persistent):
      send aref
  else:
      send a 
```

Please see individual patches for more details.

/reviewed-on nexedi/wendelin.core!6

Rationale
---------

Array reference could be useful in situations where one needs to pass arrays
between processes and instead of copying array data, leverage the fact that
top-level array, for example ZBigArray, is already persisted separately, and
only send small amount of information referencing data in question.

Implementation
--------------

BigArray is not regular NumPy array and so needs explicit support in
ArrayRef code to find root object and indices. This patch adds such
support via the following way:

- when BigArray.__getitem__ creates VMA, it remembers in the VMA
  the top-level BigArray object under which this VMA was created.

- when ArrayRef is finding root, it can detect such VMAs, because it will
  be pointed to by the most top regular ndarray's .base, and in turn gets
  top-level BigArray object from the VMA.

- further all indices computations are performed, similarly to complete regular
  ndarrays case, on ndarrays root and a. But in the end .lo and .hi are
  adjusted for the corresponding offset of where root is inside whole
  BigArray.

- there is no need to adjust .deref() at all.

For remembering information into a VMA and also to be able to get
(readonly) its mapping addresses _bigfile.c extension has to be extended
a bit. Since we are now storing arbitrary python object attached to
PyVMA - it can create cycles - and so PyVMA accordingly adjusted to
support cyclic garbage collector.

Please see the patch itself for more details and comments.

ArrayRef is a tool to find out for a NumPy array its top-level root
parent and remember instructions how to recreate original array from
the root. For example if

	root = arange(1E7)
	z = root[1000:2000]
	a = z[10:20]

`ArrayRef(a)` will find out that the root array for `a` is `root` and
that `a` occupies 1010:1020 bytes in it. The vice versa operation is
also possible, for example given

	aref = ArrayRef(a)

it is possible to restore original `a` from `aref`:

	a_ = aref.deref()
	assert array_equal(a_, a)

the restoration works without copying by creating appropriate view of
root.

ArrayRef should work reliably for arrays of arbitrary dimensions,
strides etc - even fancy arrays created via stride tricks such as arrays
whose elements overlap each other should be supported.

This patch adds ArrayRef with support for regular ndarrays only.

The next patch will add ArrayRef support for BigArray and description
for ArrayRef rationale.

This allows e.g. to open `neo://cluster@master?compress=false` - in
other words with using options, which our current simplified opening
code does not support.

Keep old dbstoropen around as the fallback to work when
zodbtools/zodburi are not available, since we still want to try to
support ZODB 3.10.

It was

	bigfile/pagefault.c:45:36: warning: ‘struct ucontext’ declared inside parameter list will not be visible outside of this definition or declaration
	 static int faulted_by(const struct ucontext *uc);
	                                    ^~~~~~~~
	bigfile/pagefault.c: In function ‘on_pagefault’:
	bigfile/pagefault.c:59:24: warning: passing argument 1 of ‘faulted_by’ from incompatible pointer type [-Wincompatible-pointer-types]
	     write = faulted_by(uc);
	                        ^~
	bigfile/pagefault.c:45:12: note: expected ‘const struct ucontext *’ but argument is of type ‘struct ucontext *’
	 static int faulted_by(const struct ucontext *uc);
	            ^~~~~~~~~~
	bigfile/pagefault.c: At top level:
	bigfile/pagefault.c:208:36: warning: ‘struct ucontext’ declared inside parameter list will not be visible outside of this definition or declaration
	 static int faulted_by(const struct ucontext *uc)
	                                    ^~~~~~~~
	bigfile/pagefault.c:208:12: error: conflicting types for ‘faulted_by’
	 static int faulted_by(const struct ucontext *uc)
	            ^~~~~~~~~~
	bigfile/pagefault.c:45:12: note: previous declaration of ‘faulted_by’ was here
	 static int faulted_by(const struct ucontext *uc);
	            ^~~~~~~~~~
	bigfile/pagefault.c: In function ‘faulted_by’:
	bigfile/pagefault.c:217:15: error: dereferencing pointer to incomplete type ‘const struct ucontext’
	     write = uc->uc_mcontext.gregs[REG_ERR] & 0x2;
	               ^~
	bigfile/pagefault.c: At top level:
	bigfile/pagefault.c:45:12: warning: ‘faulted_by’ used but never defined
	 static int faulted_by(const struct ucontext *uc);
	            ^~~~~~~~~~
	bigfile/pagefault.c:208:12: warning: ‘faulted_by’ defined but not used [-Wunused-function]
	 static int faulted_by(const struct ucontext *uc)
	            ^~~~~~~~~~

Change to using ucontext_t because apparently there is no `struct
ucontext` anymore (and man for sigaction says 3rd parameter to hander is
of type `ucontext_t *` - not `struct ucontext *` - cast to `void *`)

Explicitly include <ucontext.h> because we are dereferencing ucontext_t,
even though today it appears to be included by <signal.h>.

Benchmark the time it takes for virtmem to handle pagefault with noop
loadblk for loadblk both implemented in C and in Python.

On my computer it is:

	name          µs/op
	PagefaultC    269 ± 0%
	pagefault_py  291 ± 0%

Quite a big time in other words.

It turned out to be mostly spent in fallocate'ing pages on tmpfs from
/dev/shm. Part of the above 269 µs/op is taken by freeing (reclaiming)
pages back when benchmarking work size exceed /dev/shm size, and part to
allocating.

If I limit the work size (via npage in benchmem.c) to be less than whole
/dev/shm it starts to be ~ 170 µs/op and with additional tracing it
shows as something like this:

    	.. on_pagefault_start   0.954 µs
    	.. vma_on_pagefault_pre 0.954 µs
    	.. ramh_alloc_page_pre  0.954 µs
    	.. ramh_alloc_page      169.992 µs
    	.. vma_on_pagefault     172.853 µs
    	.. vma_on_pagefault_pre 172.853 µs
    	.. vma_on_pagefault     174.046 µs
    	.. on_pagefault_end     174.046 µs
    	.. whole:               171.900 µs

so almost all time is spent in ramh_alloc_page which is doing the fallocate:

	https://lab.nexedi.com/nexedi/wendelin.core/blob/f11386a4/bigfile/ram_shmfs.c#L125

Simple benchmark[1] confirmed it is indeed the case for fallocate(tmpfs) to be
relatively slow[2] (and that for recent kernels it regressed somewhat
compared to Linux 3.16). Profile flamegraph for that benchmark[3] shows
internal loading of shmem_fallocate which for 1 hardware page is not
that too slow (e.g. <1µs) but when a request comes for a region
internally performs it page by page and so accumulates that ~ 170µs for 2M.

I've tried to briefly rerun the benchmark with huge pages activated on /dev/shm via

	mount /dev/shm -o huge=always,remount

as both regular user and as root but it was executing several times
slower. Probably something to investigate more later.

[1] https://lab.nexedi.com/kirr/misc/blob/4f84a06e/tmpfs/t_fallocate.c
[2] https://lab.nexedi.com/kirr/misc/blob/4f84a06e/tmpfs/1.txt
[3] https://lab.nexedi.com/kirr/misc/raw/4f84a06e/tmpfs/fallocate-2M-nohuge.svg

Rework py.bench output to match output of Go benchmarking[1] so that go
tools like benchstat & friends could be used to analyze and compare the
timings.

Before patch:

============================= test session starts ==============================
platform linux2 -- Python 2.7.14, pytest-3.3.2.dev2+g88f2cc9b.d20171206, py-1.5.2, pluggy-0.6.0
rootdir: /home/kirr/src/wendelin/wendelin.core, inifile:
collected 11 items

pymod: bigfile/tests/bench_0virtmem.py
bench_file_mmapread_hole	0.21  (0.39 0.22 0.21)
bench_file_read_hole    	0.24  (0.24 0.24 0.24)
bench_file_readbig_hole 	0.30  (0.30 0.31 0.31)
bench_bigf_read_hole    	0.44  (0.44 0.45 0.44)
bench_file_mmapwrite0   	0.13  (0.13 0.13 0.13)
bench_file_write55      	0.08  (0.08 0.08 0.08)
bench_bigf_writeff      	0.47  (0.47 0.48 0.47)
bench_file_mmapread     	0.22  (0.22 0.22 0.22)
bench_file_read         	0.25  (0.25 0.25 0.26)
bench_file_readbig      	0.31  (0.31 0.31 0.31)
bench_bigf_read         	0.44  (0.45 0.44 0.44)

========================== 11 passed in 12.92 seconds ==========================

After patch:

============================= test session starts ==============================
platform linux2 -- Python 2.7.14, pytest-3.3.2.dev2+g88f2cc9b.d20171206, py-1.5.2, pluggy-0.6.0
rootdir: /home/kirr/src/wendelin/wendelin.core, inifile:
collected 11 items

pymod: bigfile/tests/bench_0virtmem.py
Benchmarkfile_mmapread_hole	1	385839.939 µs/op
Benchmarkfile_mmapread_hole	1	219214.916 µs/op
Benchmarkfile_mmapread_hole	1	210209.131 µs/op
Benchmarkfile_read_hole    	1	238974.094 µs/op
Benchmarkfile_read_hole    	1	237294.197 µs/op
Benchmarkfile_read_hole    	1	238043.070 µs/op
Benchmarkfile_readbig_hole 	1	301330.090 µs/op
Benchmarkfile_readbig_hole 	1	301767.111 µs/op
Benchmarkfile_readbig_hole 	1	301135.063 µs/op
Benchmarkbigf_read_hole    	1	434718.132 µs/op
Benchmarkbigf_read_hole    	1	435019.970 µs/op
Benchmarkbigf_read_hole    	1	434729.099 µs/op
Benchmarkfile_mmapwrite0   	1	126471.996 µs/op
Benchmarkfile_mmapwrite0   	1	125886.917 µs/op
Benchmarkfile_mmapwrite0   	1	125730.038 µs/op
Benchmarkfile_write55      	1	86760.044 µs/op
Benchmarkfile_write55      	1	87507.010 µs/op
Benchmarkfile_write55      	1	87735.891 µs/op
Benchmarkbigf_writeff      	1	448369.980 µs/op
Benchmarkbigf_writeff      	1	448238.850 µs/op
Benchmarkbigf_writeff      	1	447322.845 µs/op
Benchmarkfile_mmapread     	1	207049.131 µs/op
Benchmarkfile_mmapread     	1	207813.978 µs/op
Benchmarkfile_mmapread     	1	210857.868 µs/op
Benchmarkfile_read         	1	238364.935 µs/op
Benchmarkfile_read         	1	236908.913 µs/op
Benchmarkfile_read         	1	238602.161 µs/op
Benchmarkfile_readbig      	1	303429.842 µs/op
Benchmarkfile_readbig      	1	302191.973 µs/op
Benchmarkfile_readbig      	1	304115.057 µs/op
Benchmarkbigf_read         	1	435079.098 µs/op
Benchmarkbigf_read         	1	434193.850 µs/op
Benchmarkbigf_read         	1	434813.976 µs/op

========================== 11 passed in 12.54 seconds ==========================

benchstat of new output:

	name                µs/op
	file_mmapread_hole   272k ±42%
	file_read_hole       238k ± 0%
	file_readbig_hole    301k ± 0%
	bigf_read_hole       435k ± 0%
	file_mmapwrite0      126k ± 0%
	file_write55        87.3k ± 1%
	bigf_writeff         448k ± 0%
	file_mmapread        209k ± 1%
	file_read            238k ± 0%
	file_readbig         303k ± 0%
	bigf_read            435k ± 0%

--------

Not only the output format is reworked here, but also b fixture is added
to BenchPlugin so that functions which accept it as arg, can run the
benchmark b.N times, can stop/restart timer etc - similar to
https://golang.org/pkg/testing/#B . If a bench_* func does not accept b,
B is still created, but b.N is assumed to be always 1.

The first benchmark which actually uses b will come in the next patch.

[1] https://github.com/golang/proposal/blob/master/design/14313-benchmark-format.md

Such directories are left in worktree after py.test run.

For several benchmarks in a python module instead of always printing
whole benchmark function path (nodeid in pytest speak), first print

	pymod: modulename

header, and then only function names.

Before patch:

============================= test session starts ==============================
platform linux2 -- Python 2.7.14, pytest-3.3.0, py-1.5.2, pluggy-0.6.0
rootdir: /home/kirr/src/wendelin/wendelin.core, inifile:
collected 14 items

bigfile/tests/bench_0virtmem.py::bench_file_mmapread_hole 	0.22  (0.39 0.22 0.22)
bigfile/tests/bench_0virtmem.py::bench_file_read_hole    	0.24  (0.24 0.24 0.24)
bigfile/tests/bench_0virtmem.py::bench_file_readbig_hole 	0.30  (0.30 0.30 0.30)
bigfile/tests/bench_0virtmem.py::bench_bigf_read_hole    	0.43  (0.43 0.43 0.43)
bigfile/tests/bench_0virtmem.py::bench_file_mmapwrite0   	0.12  (0.13 0.12 0.13)
bigfile/tests/bench_0virtmem.py::bench_file_write55      	0.08  (0.08 0.08 0.08)
bigfile/tests/bench_0virtmem.py::bench_bigf_writeff      	0.45  (0.45 0.45 0.45)
bigfile/tests/bench_0virtmem.py::bench_file_mmapread     	0.21  (0.21 0.21 0.22)
bigfile/tests/bench_0virtmem.py::bench_file_read         	0.23  (0.23 0.24 0.24)
bigfile/tests/bench_0virtmem.py::bench_file_readbig      	0.30  (0.30 0.30 0.30)
bigfile/tests/bench_0virtmem.py::bench_bigf_read         	0.43  (0.44 0.43 0.44)
bigfile/tests/bench_1filezodb.py::bench_bigz_readhole    	0.42  (0.42 0.43 0.43)
bigfile/tests/bench_1filezodb.py::bench_bigz_writeff     	0.84  (0.84 1.25 1.25)
bigfile/tests/bench_1filezodb.py::bench_bigz_read        	0.60  (0.64 0.60 0.60)
========================== 14 passed in 21.78 seconds ==========================

After patch:

============================= test session starts ==============================
platform linux2 -- Python 2.7.14, pytest-3.3.0, py-1.5.2, pluggy-0.6.0
rootdir: /home/kirr/src/wendelin/wendelin.core, inifile:
collected 14 items

pymod: bigfile/tests/bench_0virtmem.py
bench_file_mmapread_hole	0.21  (0.39 0.22 0.21)
bench_file_read_hole    	0.24  (0.24 0.24 0.24)
bench_file_readbig_hole 	0.30  (0.30 0.30 0.30)
bench_bigf_read_hole    	0.43  (0.43 0.43 0.43)
bench_file_mmapwrite0   	0.12  (0.13 0.12 0.13)
bench_file_write55      	0.08  (0.08 0.08 0.08)
bench_bigf_writeff      	0.45  (0.52 0.51 0.45)
bench_file_mmapread     	0.21  (0.21 0.21 0.21)
bench_file_read         	0.24  (0.24 0.24 0.24)
bench_file_readbig      	0.30  (0.30 0.30 0.30)
bench_bigf_read         	0.43  (0.43 0.43 0.43)

pymod: bigfile/tests/bench_1filezodb.py
bench_bigz_readhole     	0.43  (0.43 0.43 0.43)
bench_bigz_writeff      	0.83  (0.83 1.20 1.21)
bench_bigz_read         	0.60  (0.65 0.60 0.60)

========================== 14 passed in 21.80 seconds ==========================

The `key: value` header is compatible with Go benchmark format[1] and
further we'll be trying to teach py.bench to output results in that
format so that Go benchmarking tools like benchstat and perf.golang.org
could be used for free.

[1] https://github.com/golang/proposal/blob/master/design/14313-benchmark-format.md

Upstream pytest changed TerminalReporter._locationline() signature from

	def _locationline(self, collect_fspath, fspath, lineno, domain):

to

	def _locationline(self, nodeid, fspath, lineno, domain):

https://github.com/pytest-dev/pytest/commit/d73e6899 .

This way without adjusting py.bench was reporting just filenames instead
of benchmark names, e.g. this way:

(z-dev) kirr@deco:~/src/wendelin/wendelin.core$ ./t/py.bench bigfile/tests/bench_0virtmem.py
=============================================================== test session starts ===============================================================
platform linux2 -- Python 2.7.14, pytest-3.3.0, py-1.5.2, pluggy-0.6.0
rootdir: /home/kirr/src/wendelin/wendelin.core, inifile:
collected 11 items

bigfile/tests/bench_0virtmem.py                                 0.21  (0.38 0.22 0.21)
bigfile/tests/bench_0virtmem.py                                 0.23  (0.23 0.24 0.23)
bigfile/tests/bench_0virtmem.py                                 0.30  (0.30 0.30 0.30)
bigfile/tests/bench_0virtmem.py                                 0.43  (0.43 0.43 0.43)
bigfile/tests/bench_0virtmem.py                                 0.12  (0.12 0.12 0.12)
bigfile/tests/bench_0virtmem.py                                 0.08  (0.08 0.08 0.08)
bigfile/tests/bench_0virtmem.py                                 0.44  (0.44 0.44 0.44)
bigfile/tests/bench_0virtmem.py                                 0.20  (0.20 0.20 0.21)
bigfile/tests/bench_0virtmem.py                                 0.24  (0.24 0.24 0.24)
bigfile/tests/bench_0virtmem.py                                 0.30  (0.30 0.30 0.30)
bigfile/tests/bench_0virtmem.py                                 0.43  (0.43 0.43 0.43)

=========================================================== 11 passed in 12.39 seconds ============================================================

Fix it.

In pytest3 pytest_runtest_call hook is always run as multicall and there
is no way to control to disable it and force e.g. 'firstresult'
behaviour. This way call.result in pytest_runtest_makereport is always a
list of returned results, not the first result itself.

Adjust the code in pytest_runtest_makereport to emulate 'firstresult'
behaviour manually.

Without the patch with recent pytest py.bench was crashing like this:

---- 8< ----
(z-dev) kirr@link:~/src/wendelin/wendelin.core$ make bench
python setup.py ll_build_ext --inplace
running ll_build_ext
copying build/lib.linux-x86_64-2.7/wendelin/bigfile/_bigfile.so -> bigfile
python t/py.bench --ignore=3rdparty --ignore=build --ignore=t
============================================================= test session starts ==============================================================
platform linux2 -- Python 2.7.14, pytest-3.3.0, py-1.5.2, pluggy-0.6.0
rootdir: /home/kirr/src/wendelin/wendelin.core, inifile:
collected 14 items

bigfile/tests/bench_0virtmem.py                          	INTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/_pytest/main.py", line 103, in wrap_session
INTERNALERROR>     session.exitstatus = doit(config, session) or 0
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/_pytest/main.py", line 141, in _main
INTERNALERROR>     config.hook.pytest_runtestloop(session=session)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/__init__.py", line 617, in __call__
INTERNALERROR>     return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/__init__.py", line 222, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/__init__.py", line 216, in <lambda>
INTERNALERROR>     firstresult=hook.spec_opts.get('firstresult'),
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/callers.py", line 201, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/callers.py", line 77, in get_result
INTERNALERROR>     _reraise(*ex)  # noqa
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/callers.py", line 180, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/_pytest/main.py", line 164, in pytest_runtestloop
INTERNALERROR>     item.config.hook.pytest_runtest_protocol(item=item, nextitem=nextitem)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/__init__.py", line 617, in __call__
INTERNALERROR>     return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/__init__.py", line 222, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/__init__.py", line 216, in <lambda>
INTERNALERROR>     firstresult=hook.spec_opts.get('firstresult'),
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/callers.py", line 201, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/callers.py", line 77, in get_result
INTERNALERROR>     _reraise(*ex)  # noqa
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/callers.py", line 180, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/_pytest/runner.py", line 63, in pytest_runtest_protocol
INTERNALERROR>     runtestprotocol(item, nextitem=nextitem)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/_pytest/runner.py", line 77, in runtestprotocol
INTERNALERROR>     reports.append(call_and_report(item, "call", log))
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/_pytest/runner.py", line 161, in call_and_report
INTERNALERROR>     hook.pytest_runtest_logreport(report=report)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/__init__.py", line 617, in __call__
INTERNALERROR>     return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/__init__.py", line 222, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/__init__.py", line 216, in <lambda>
INTERNALERROR>     firstresult=hook.spec_opts.get('firstresult'),
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/callers.py", line 201, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/callers.py", line 77, in get_result
INTERNALERROR>     _reraise(*ex)  # noqa
INTERNALERROR>   File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pluggy/callers.py", line 180, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "t/py.bench", line 165, in pytest_runtest_logreport
INTERNALERROR>     self._tw.write('%.2f' % min(report.bench_times))
INTERNALERROR> TypeError: float argument required, not list