1. 17 Sep, 2019 11 commits
    • Kirill Smelkov's avatar
      pygolang v0.0.4 · 1573d101
      Kirill Smelkov authored
      This release is bugfix-only. Compared to pygolang v0.0.3 (4ca65816)
      the change in speed is likely within noise:
      
           (on i7@2.6GHz)
      
      thread runtime:
      
          name             old time/op  new time/op  delta
          go               18.3µs ± 1%  18.3µs ± 1%    ~     (p=0.218 n=10+10)
          chan             2.97µs ± 5%  2.97µs ± 8%    ~     (p=0.781 n=10+10)
          select           3.59µs ± 2%  3.55µs ± 5%    ~     (p=0.447 n=9+10)
          def              56.0ns ± 0%  55.0ns ± 0%  -1.79%  (p=0.000 n=10+10)
          func_def         43.7µs ± 1%  43.8µs ± 1%  +0.35%  (p=0.029 n=10+10)
          call             65.0ns ± 0%  62.3ns ± 1%  -4.15%  (p=0.000 n=10+10)
          func_call        1.06µs ± 1%  1.04µs ± 0%  -1.26%  (p=0.000 n=10+8)
          try_finally       137ns ± 1%   137ns ± 0%    ~     (p=1.000 n=10+10)
          defer            2.32µs ± 0%  2.33µs ± 1%  +0.43%  (p=0.000 n=9+10)
          workgroup_empty  37.6µs ± 1%  37.1µs ± 2%  -1.29%  (p=0.003 n=10+10)
          workgroup_raise  47.9µs ± 1%  47.6µs ± 0%  -0.63%  (p=0.001 n=9+9)
      
      gevent runtime:
      
          name             old time/op  new time/op  delta
          go               15.8µs ± 0%  16.1µs ± 1%  +2.18%  (p=0.000 n=9+10)
          chan             7.36µs ± 0%  7.21µs ± 0%  -1.97%  (p=0.000 n=8+10)
          select           10.4µs ± 0%  10.5µs ± 0%  +0.71%  (p=0.000 n=10+10)
          def              57.0ns ± 0%  55.0ns ± 0%  -3.51%  (p=0.000 n=10+10)
          func_def         43.3µs ± 1%  44.1µs ± 2%  +1.81%  (p=0.000 n=10+10)
          call             66.0ns ± 0%  65.0ns ± 0%  -1.52%  (p=0.000 n=10+10)
          func_call        1.04µs ± 1%  1.06µs ± 1%  +1.48%  (p=0.000 n=10+10)
          try_finally       137ns ± 1%   136ns ± 0%  -1.31%  (p=0.000 n=10+10)
          defer            2.32µs ± 0%  2.31µs ± 1%    ~     (p=0.472 n=8+10)
          workgroup_empty  56.0µs ± 0%  55.7µs ± 0%  -0.49%  (p=0.000 n=10+10)
          workgroup_raise  71.3µs ± 1%  71.7µs ± 1%  +0.62%  (p=0.001 n=10+10)
      1573d101
    • Kirill Smelkov's avatar
      libgolang: select: zero-out waitv before freeing · 2e01f9bd
      Kirill Smelkov authored
      Like we already do for e.g. _chan, to increase probability that if
      something is used after free we get a NULL-dereference crash instead of
      more hard-to-understand segfault.
      2e01f9bd
    • Kirill Smelkov's avatar
      libgolang: Fix select crash while accessing destroyed channel upon wakeup · 5aa1e899
      Kirill Smelkov authored
      Similarly to situation described in dcf4ebd1 (libgolang: Fix chan.close
      to dequeue subscribers atomically), select can be also accessing a
      channel object at the time of wakeup when that channel could be already
      destroyed: select queues waiters to channels recv/send queues and upon
      wakeup needs to dequeue them. This requires locking channels, not to
      mention that a channel destroy with non-empty subscribers queue will
      trigger bug panic.
      
      Contrary to the fix for recv, we cannot rework select not to access
      channel objects after wakeup, because for select upon wakeup all queued
      channels could be already destroyed, not only selected one. Thus the fix
      here is to incref/decref the channels for the duration where we need to
      access them.
      
      The bug was not caught by existing tests and was noted while doing
      libgolang.cpp review for concurrency issues. With added test (hereby fix
      is served by a bit amended _test_close_wakeup_all) the bug, if not
      fixed, renders itself as e.g. the following under TSAN:
      
      WARNING: ThreadSanitizer: data race (pid=4421)
        Write of size 8 at 0x7b1400000650 by thread T9:
          #0 free ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:649 (libtsan.so.0+0x2b46a)
          #1 free ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:643 (libtsan.so.0+0x2b46a)
          #2 golang::_chan::decref() golang/runtime/libgolang.cpp:479 (liblibgolang.so.0.1+0x4822)
          #3 _chanxdecref golang/runtime/libgolang.cpp:461 (liblibgolang.so.0.1+0x487a)
          #4 golang::chan<int>::operator=(decltype(nullptr)) golang/libgolang.h:296 (_golang_test.so+0x14cf9)
          #5 operator() golang/runtime/libgolang_test.cpp:304 (_golang_test.so+0x14cf9)
          #6 __invoke_impl<void, __test_close_wakeup_all(bool)::<lambda()>&> /usr/include/c++/8/bits/invoke.h:60 (_golang_test.so+0x14cf9)
          #7 __invoke<__test_close_wakeup_all(bool)::<lambda()>&> /usr/include/c++/8/bits/invoke.h:95 (_golang_test.so+0x14cf9)
          #8 __call<void> /usr/include/c++/8/functional:400 (_golang_test.so+0x14cf9)
          #9 operator()<> /usr/include/c++/8/functional:484 (_golang_test.so+0x14cf9)
          #10 _M_invoke /usr/include/c++/8/bits/std_function.h:297 (_golang_test.so+0x14cf9)
          #11 std::function<void ()>::operator()() const /usr/include/c++/8/bits/std_function.h:687 (_golang_test.so+0x1850c)
          #12 operator() golang/libgolang.h:273 (_golang_test.so+0x1843a)
          #13 _FUN golang/libgolang.h:271 (_golang_test.so+0x1843a)
          #14 <null> <null> (python2.7+0x1929e3)
      
        Previous read of size 8 at 0x7b1400000650 by thread T10:
          #0 golang::Sema::acquire() golang/runtime/libgolang.cpp:168 (liblibgolang.so.0.1+0x413a)
          #1 golang::Mutex::lock() golang/runtime/libgolang.cpp:179 (liblibgolang.so.0.1+0x424a)
          #2 operator() golang/runtime/libgolang.cpp:1044 (liblibgolang.so.0.1+0x424a)
          #3 _M_invoke /usr/include/c++/8/bits/std_function.h:297 (liblibgolang.so.0.1+0x424a)
          #4 std::function<void ()>::operator()() const /usr/include/c++/8/bits/std_function.h:687 (liblibgolang.so.0.1+0x5f07)
          #5 golang::_deferred::~_deferred() golang/runtime/libgolang.cpp:215 (liblibgolang.so.0.1+0x5f07)
          #6 __chanselect2 golang/runtime/libgolang.cpp:1044 (liblibgolang.so.0.1+0x5f07)
          #7 _chanselect2<true> golang/runtime/libgolang.cpp:968 (liblibgolang.so.0.1+0x6665)
          #8 _chanselect golang/runtime/libgolang.cpp:963 (liblibgolang.so.0.1+0x6665)
          #9 select golang/libgolang.h:386 (_golang_test.so+0x14fc1)
          #10 operator() golang/runtime/libgolang_test.cpp:320 (_golang_test.so+0x14fc1)
          #11 __invoke_impl<void, __test_close_wakeup_all(bool)::<lambda()>&> /usr/include/c++/8/bits/invoke.h:60 (_golang_test.so+0x14fc1)
          #12 __invoke<__test_close_wakeup_all(bool)::<lambda()>&> /usr/include/c++/8/bits/invoke.h:95 (_golang_test.so+0x14fc1)
          #13 __call<void> /usr/include/c++/8/functional:400 (_golang_test.so+0x14fc1)
          #14 operator()<> /usr/include/c++/8/functional:484 (_golang_test.so+0x14fc1)
          #15 _M_invoke /usr/include/c++/8/bits/std_function.h:297 (_golang_test.so+0x14fc1)
          #16 std::function<void ()>::operator()() const /usr/include/c++/8/bits/std_function.h:687 (_golang_test.so+0x1850c)
          #17 operator() golang/libgolang.h:273 (_golang_test.so+0x183da)
          #18 _FUN golang/libgolang.h:271 (_golang_test.so+0x183da)
          #19 <null> <null> (python2.7+0x1929e3)
      
        Thread T9 (tid=4661, running) created by main thread at:
          #0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:915 (libtsan.so.0+0x2be1b)
          #1 PyThread_start_new_thread <null> (python2.7+0x19299f)
          #2 _taskgo golang/runtime/libgolang.cpp:123 (liblibgolang.so.0.1+0x3f98)
          #3 go<__test_close_wakeup_all(bool)::<lambda()> > golang/libgolang.h:271 (_golang_test.so+0x16c94)
          #4 __test_close_wakeup_all(bool) golang/runtime/libgolang_test.cpp:298 (_golang_test.so+0x16c94)
          #5 _test_close_wakeup_all_vsselect() golang/runtime/libgolang_test.cpp:342 (_golang_test.so+0x16f64)
          #6 __pyx_pf_6golang_12_golang_test_24test_close_wakeup_all_vsselect golang/_golang_test.cpp:4013 (_golang_test.so+0xd92a)
          #7 __pyx_pw_6golang_12_golang_test_25test_close_wakeup_all_vsselect golang/_golang_test.cpp:3978 (_golang_test.so+0xd92a)
          #8 PyEval_EvalFrameEx <null> (python2.7+0xf68b4)
      
        Thread T10 (tid=4662, running) created by main thread at:
          #0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:915 (libtsan.so.0+0x2be1b)
          #1 PyThread_start_new_thread <null> (python2.7+0x19299f)
          #2 _taskgo golang/runtime/libgolang.cpp:123 (liblibgolang.so.0.1+0x3f98)
          #3 go<__test_close_wakeup_all(bool)::<lambda()> > golang/libgolang.h:271 (_golang_test.so+0x16d96)
          #4 __test_close_wakeup_all(bool) golang/runtime/libgolang_test.cpp:315 (_golang_test.so+0x16d96)
          #5 _test_close_wakeup_all_vsselect() golang/runtime/libgolang_test.cpp:342 (_golang_test.so+0x16f64)
          #6 __pyx_pf_6golang_12_golang_test_24test_close_wakeup_all_vsselect golang/_golang_test.cpp:4013 (_golang_test.so+0xd92a)
          #7 __pyx_pw_6golang_12_golang_test_25test_close_wakeup_all_vsselect golang/_golang_test.cpp:3978 (_golang_test.so+0xd92a)
          #8 PyEval_EvalFrameEx <null> (python2.7+0xf68b4)
      
      and reliably crashes under regular builds.
      5aa1e899
    • Kirill Smelkov's avatar
      libgolang: Fix select to wait for won-while-queueing case · 65c43848
      Kirill Smelkov authored
      During the second phase of select - after all cases were polled and
      noone was found to be ready - cases are queued to corresponding channels
      recv and send queues. While that queueing is in progress, a case, that
      was already queued, could win (see f0b592b4 "select: Don't let both a
      queued and a tried cases win at the same time" for details).
      
      If such won case is detected, we break out of queuing loop, but
      currently don't wait for that case to become ready. This is a bug,
      because when a case is marked as won, its data is not yet copied - for
      example for won recv case if we don't wait for that case to become
      ready, we will be returning from select while corresponding *prx and
      *rxok for recv waiter is still being copied in progress.
      
      An example TSAN reports for this bug are as follows:
      
      (1) WARNING: ThreadSanitizer: data race (pid=8223)
        Read of size 1 at 0x7b1800000a48 by main thread:
          #0 __chanselect2 golang/runtime/libgolang.cpp:1112 (liblibgolang.so.0.1+0x5fd6)
          #1 _chanselect2<true> golang/runtime/libgolang.cpp:949 (liblibgolang.so.0.1+0x6665)
          #2 _chanselect golang/runtime/libgolang.cpp:944 (liblibgolang.so.0.1+0x6665)
          #3 __pyx_f_6golang_7_golang__chanselect_pyexc golang/_golang.cpp:5896 (_golang.so+0x1deac)
          #4 __pyx_pf_6golang_7_golang_4pyselect golang/_golang.cpp:4935 (_golang.so+0x1deac)
          #5 __pyx_pw_6golang_7_golang_5pyselect golang/_golang.cpp:4355 (_golang.so+0x1deac)
          #6 PyEval_EvalFrameEx <null> (python2.7+0xf0e49)
      
        Previous write of size 1 at 0x7b1800000a48 by thread T57:
          #0 golang::_RecvSendWaiting::wakeup(bool) golang/runtime/libgolang.cpp:346 (liblibgolang.so.0.1+0x459d)
          #1 golang::_chan::_tryrecv(void*, bool*) golang/runtime/libgolang.cpp:730 (liblibgolang.so.0.1+0x511d)
          #2 __chanselect2 golang/runtime/libgolang.cpp:1074 (liblibgolang.so.0.1+0x5d4b)
          #3 _chanselect2<true> golang/runtime/libgolang.cpp:949 (liblibgolang.so.0.1+0x6665)
          #4 _chanselect golang/runtime/libgolang.cpp:944 (liblibgolang.so.0.1+0x6665)
          #5 __pyx_f_6golang_7_golang__chanselect_pyexc golang/_golang.cpp:5896 (_golang.so+0x1deac)
          #6 __pyx_pf_6golang_7_golang_4pyselect golang/_golang.cpp:4935 (_golang.so+0x1deac)
          #7 __pyx_pw_6golang_7_golang_5pyselect golang/_golang.cpp:4355 (_golang.so+0x1deac)
          #8 PyEval_EvalFrameEx <null> (python2.7+0xf0e49)
          #9 <null> <null> (python2.7+0x1929e3)
      
        Location is heap block of size 96 at 0x7b1800000a20 allocated by main thread:
          #0 calloc ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:623 (libtsan.so.0+0x2b323)
          #1 calloc ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:618 (libtsan.so.0+0x2b323)
          #2 __chanselect2 golang/runtime/libgolang.cpp:1018 (liblibgolang.so.0.1+0x5b8c)
          #3 _chanselect2<true> golang/runtime/libgolang.cpp:949 (liblibgolang.so.0.1+0x6665)
          #4 _chanselect golang/runtime/libgolang.cpp:944 (liblibgolang.so.0.1+0x6665)
          #5 __pyx_f_6golang_7_golang__chanselect_pyexc golang/_golang.cpp:5896 (_golang.so+0x1deac)
          #6 __pyx_pf_6golang_7_golang_4pyselect golang/_golang.cpp:4935 (_golang.so+0x1deac)
          #7 __pyx_pw_6golang_7_golang_5pyselect golang/_golang.cpp:4355 (_golang.so+0x1deac)
          #8 PyEval_EvalFrameEx <null> (python2.7+0xf0e49)
      
        Thread T57 (tid=13758, finished) created by main thread at:
          #0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:915 (libtsan.so.0+0x2be1b)
          #1 PyThread_start_new_thread <null> (python2.7+0x19299f)
          #2 _taskgo golang/runtime/libgolang.cpp:123 (liblibgolang.so.0.1+0x3f98)
          #3 __pyx_f_6golang_7_golang__taskgo_pyexc golang/_golang.cpp:5926 (_golang.so+0x16f7e)
          #4 __pyx_pf_6golang_7_golang_2pygo golang/_golang.cpp:2399 (_golang.so+0x16f7e)
          #5 __pyx_pw_6golang_7_golang_3pygo golang/_golang.cpp:2324 (_golang.so+0x16f7e)
          #6 PyEval_EvalFrameEx <null> (python2.7+0xf0e49)
      
      (2) WARNING: ThreadSanitizer: data race (pid=14185)
        Write of size 8 at 0x7b1800003000 by thread T95:
          #0 free ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:649 (libtsan.so.0+0x2b46a)
          #1 free ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:643 (libtsan.so.0+0x2b46a)
          #2 operator() golang/runtime/libgolang.cpp:1023 (liblibgolang.so.0.1+0x44bd)
          #3 _M_invoke /usr/include/c++/8/bits/std_function.h:297 (liblibgolang.so.0.1+0x44bd)
          #4 std::function<void ()>::operator()() const /usr/include/c++/8/bits/std_function.h:687 (liblibgolang.so.0.1+0x5fd8)
          #5 golang::_deferred::~_deferred() golang/runtime/libgolang.cpp:215 (liblibgolang.so.0.1+0x5fd8)
          #6 __chanselect2 golang/runtime/libgolang.cpp:1023 (liblibgolang.so.0.1+0x5fd8)
          #7 _chanselect2<true> golang/runtime/libgolang.cpp:949 (liblibgolang.so.0.1+0x6736)
          #8 _chanselect golang/runtime/libgolang.cpp:944 (liblibgolang.so.0.1+0x6736)
          #9 __pyx_f_6golang_7_golang__chanselect_pyexc golang/_golang.cpp:5896 (_golang.cpython-36m-x86_64-linux-gnu.so+0x1e562)
          #10 __pyx_pf_6golang_7_golang_4pyselect golang/_golang.cpp:4935 (_golang.cpython-36m-x86_64-linux-gnu.so+0x1e562)
          #11 __pyx_pw_6golang_7_golang_5pyselect golang/_golang.cpp:4355 (_golang.cpython-36m-x86_64-linux-gnu.so+0x1e562)
          #12 _PyCFunction_FastCallDict Objects/methodobject.c:231 (python3.6+0xd4db9)
          #13 pythread_wrapper Python/thread_pthread.h:205 (python3.6+0x6c5d6)
      
        Previous read of size 8 at 0x7b1800003000 by main thread:
          #0 golang::_RecvSendWaiting::wakeup(bool) golang/runtime/libgolang.cpp:347 (liblibgolang.so.0.1+0x4769)
          #1 golang::_chan::_trysend(void const*) golang/runtime/libgolang.cpp:661 (liblibgolang.so.0.1+0x5781)
          #2 _chanselect golang/runtime/libgolang.cpp:901 (liblibgolang.so.0.1+0x64d9)
          #3 __pyx_f_6golang_7_golang__chanselect_pyexc golang/_golang.cpp:5896 (_golang.cpython-36m-x86_64-linux-gnu.so+0x1e562)
          #4 __pyx_pf_6golang_7_golang_4pyselect golang/_golang.cpp:4935 (_golang.cpython-36m-x86_64-linux-gnu.so+0x1e562)
          #5 __pyx_pw_6golang_7_golang_5pyselect golang/_golang.cpp:4355 (_golang.cpython-36m-x86_64-linux-gnu.so+0x1e562)
          #6 _PyCFunction_FastCallDict Objects/methodobject.c:231 (python3.6+0xd4db9)
      
        Thread T95 (tid=16547, running) created by main thread at:
          #0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:915 (libtsan.so.0+0x2be1b)
          #1 PyThread_start_new_thread Python/thread_pthread.h:252 (python3.6+0x6c67e)
          #2 _taskgo golang/runtime/libgolang.cpp:123 (liblibgolang.so.0.1+0x4158)
          #3 __pyx_f_6golang_7_golang__taskgo_pyexc golang/_golang.cpp:5926 (_golang.cpython-36m-x86_64-linux-gnu.so+0x1a9b5)
          #4 __pyx_pf_6golang_7_golang_2pygo golang/_golang.cpp:2399 (_golang.cpython-36m-x86_64-linux-gnu.so+0x1a9b5)
          #5 __pyx_pw_6golang_7_golang_3pygo golang/_golang.cpp:2324 (_golang.cpython-36m-x86_64-linux-gnu.so+0x1a9b5)
          #6 _PyCFunction_FastCallDict Objects/methodobject.c:231 (python3.6+0xd4db9)
      
      -> Fix it by always waiting for WaitGroup's won case to become ready.
      
      The bug was introduced in 3b241983 (Port/move channels to C/C++/Pyx). Before
      that - when channels were implemented at Python level, we were always waiting
      on select's group.
      
      Added test catches the bug on all - even not under TSAN - builds.
      65c43848
    • Kirill Smelkov's avatar
      libgolang: Fix chan.close to dequeue subscribers atomically · dcf4ebd1
      Kirill Smelkov authored
      Currently chan.close iterates all send/recv subscribers
      unlocking/relocking the channel for each and notifying dequeued
      subscriber with channel unlocked. This leads to that even if channel had
      only one subscriber, chan.close accesses chan._mu again - after
      notifying that subscriber. That in turn means that an idiom where e.g.
      a done channel is passed to worker, which worker closes at the end, and
      main task waiting on the done and destroying done right after wakeup
      cannot work - because close, internally, accesses already destroyed
      channel as the following TSAN report shows for _test_go_c:
      
          WARNING: ThreadSanitizer: data race (pid=7143)
            Write of size 8 at 0x7b1400000650 by main thread:
              #0 free ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:649 (libtsan.so.0+0x2b46a)
              #1 free ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:643 (libtsan.so.0+0x2b46a)
              #2 golang::_chan::decref() golang/runtime/libgolang.cpp:470 (liblibgolang.so.0.1+0x47f2)
              #3 _chanxdecref golang/runtime/libgolang.cpp:452 (liblibgolang.so.0.1+0x484a)
              #4 _test_go_c golang/runtime/libgolang_test_c.c:86 (_golang_test.so+0x13a2e)
              #5 __pyx_pf_6golang_12_golang_test_12test_go_c golang/_golang_test.cpp:3340 (_golang_test.so+0xcbaa)
              #6 __pyx_pw_6golang_12_golang_test_13test_go_c golang/_golang_test.cpp:3305 (_golang_test.so+0xcbaa)
              #7 PyEval_EvalFrameEx <null> (python2.7+0xf68b4)
      
            Previous read of size 8 at 0x7b1400000650 by thread T8:
              #0 golang::Sema::acquire() golang/runtime/libgolang.cpp:164 (liblibgolang.so.0.1+0x410a)
              #1 golang::Mutex::lock() golang/runtime/libgolang.cpp:175 (liblibgolang.so.0.1+0x4c82)
              #2 golang::_chan::close() golang/runtime/libgolang.cpp:754 (liblibgolang.so.0.1+0x4c82)
              #3 _chanclose golang/runtime/libgolang.cpp:732 (liblibgolang.so.0.1+0x4d1a)
              #4 _work golang/runtime/libgolang_test_c.c:92 (_golang_test.so+0x136cc)
              #5 <null> <null> (python2.7+0x1929e3)
      
            Thread T8 (tid=7311, finished) created by main thread at:
              #0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:915 (libtsan.so.0+0x2be1b)
              #1 PyThread_start_new_thread <null> (python2.7+0x19299f)
              #2 _taskgo golang/runtime/libgolang.cpp:119 (liblibgolang.so.0.1+0x3f68)
              #3 _test_go_c golang/runtime/libgolang_test_c.c:84 (_golang_test.so+0x13a1c)
              #4 __pyx_pf_6golang_12_golang_test_12test_go_c golang/_golang_test.cpp:3340 (_golang_test.so+0xcbaa)
              #5 __pyx_pw_6golang_12_golang_test_13test_go_c golang/_golang_test.cpp:3305 (_golang_test.so+0xcbaa)
              #6 PyEval_EvalFrameEx <null> (python2.7+0xf68b4)
      
      -> Fix close to dequeue all channel's subscribers atomically, and notify
      them all after channel is unlocked and _no_ longer accessed.
      
      Close was already working this way when channels were done at Python
      level, but in 3b241983 (Port/move channels to C/C++/Pyx) I introduced
      this bug while trying to avoid additional memory allocation in close.
      
      Added test catches the bug on all - even not under TSAN - builds.
      
      ----
      
      Added test also reveals another bug: recv<onstack=false> uses channel
      after wakeup, and, as at the time of wakeup the channel could be
      already destroyed, that segfaults. Fix it by pre-reading in recv
      everything needed from _chan object before going to sleep.
      
      This fix cannot go separately from close fix, as fixed close is required
      for recv-uses-chan-after-wakeup testcase.
      dcf4ebd1
    • Kirill Smelkov's avatar
      libgolang: tests: waitBlocked: Allow to specify for how many receivers/senders should be blocked · c92a4830
      Kirill Smelkov authored
      This will be needed in the next patch.
      c92a4830
    • Kirill Smelkov's avatar
      libgolang: tests: It is not safe to capture by reference in go(<lambda>) · 44737253
      Kirill Smelkov authored
      When lambda captures stack-resided variable by reference, it actually
      remembers address of that variable and inside lambda code dereferences
      that address on variable use. The lifetime of all spawned goroutines in
      libgolang_test is subset of test function driver lifetime, so capturing
      by reference should be safe in that situation on the first glance.
      However for that to work, it is required that stacks of both goroutines
      - the main goroutine and spawned goroutine - must be live at the same
      time, so that spawned goroutine could safely retrieve a
      reference-captured variable located on the main goroutine stack.
      
      This works for thread runtime, but is known not to work for gevent
      runtime, where inactive goroutine stack is swapped onto heap and is
      generally considered "dead" while that goroutine is parked (see
      "Implementation note" in 3b241983 "Port/move channels to C/C++/Pyx" for
      details about this).
      
      -> Fix the test by capturing by value in lambdas. What we capture is
      usually chan<T> object, which itself is a pointer, so it should not make
      a big difference in efficiency. It is also more safe to capture channels
      by value, since that automatically incref/decref them and adds extra
      protection wrt lifetime management bugs.
      
      NOTE sending/receiving via channels from/to stack-based variables is
      always safe - for both thread and gevent runtimes, as channels
      implementation explicitly cares for this to work. Once again
      "Implementation note" in 3b241983 has the details.
      44737253
    • Kirill Smelkov's avatar
      libgolang: PanicError += what() · f2b77c94
      Kirill Smelkov authored
      Give what() to PanicError so that uncaught panics give proper message on
      std::terminate_handler crash instead of printing just "std::exception",
      for example
      
          terminate called after throwing an instance of 'golang::PanicError'
            what():  chan: decref: free: recvq not empty
      
      instead of
      
          terminate called after throwing an instance of 'golang::PanicError'
            what():  std::exception
      f2b77c94
    • Kirill Smelkov's avatar
      tox += ThreadSanitizer, AddressSanitizer, Python debug builds · 4dc1a7f0
      Kirill Smelkov authored
      - ThreadSanitizer helps to detect races and some memory errors,
      - AddressSanitizer helps to detect memory errors,
      - Python debug builds help to detect e.g reference counting errors.
      
      Adding all those tools to testing coverage discovers e.g. the following
      bugs (not a full list):
      
      ---- 8< ----
      
      py27-thread-tsan:
      WARNING: ThreadSanitizer: data race (pid=7143)
        Write of size 8 at 0x7b1400000650 by main thread:
          #0 free ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:649 (libtsan.so.0+0x2b46a)
          #1 free ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:643 (libtsan.so.0+0x2b46a)
          #2 golang::_chan::decref() golang/runtime/libgolang.cpp:470 (liblibgolang.so.0.1+0x47f2)
          #3 _chanxdecref golang/runtime/libgolang.cpp:452 (liblibgolang.so.0.1+0x484a)
          #4 _test_go_c golang/runtime/libgolang_test_c.c:86 (_golang_test.so+0x13a2e)
          #5 __pyx_pf_6golang_12_golang_test_12test_go_c golang/_golang_test.cpp:3340 (_golang_test.so+0xcbaa)
          #6 __pyx_pw_6golang_12_golang_test_13test_go_c golang/_golang_test.cpp:3305 (_golang_test.so+0xcbaa)
          #7 PyEval_EvalFrameEx <null> (python2.7+0xf68b4)
      
        Previous read of size 8 at 0x7b1400000650 by thread T8:
          #0 golang::Sema::acquire() golang/runtime/libgolang.cpp:164 (liblibgolang.so.0.1+0x410a)
          #1 golang::Mutex::lock() golang/runtime/libgolang.cpp:175 (liblibgolang.so.0.1+0x4c82)
          #2 golang::_chan::close() golang/runtime/libgolang.cpp:754 (liblibgolang.so.0.1+0x4c82)
          #3 _chanclose golang/runtime/libgolang.cpp:732 (liblibgolang.so.0.1+0x4d1a)
          #4 _work golang/runtime/libgolang_test_c.c:92 (_golang_test.so+0x136cc)
          #5 <null> <null> (python2.7+0x1929e3)
      
        Thread T8 (tid=7311, finished) created by main thread at:
          #0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors.cc:915 (libtsan.so.0+0x2be1b)
          #1 PyThread_start_new_thread <null> (python2.7+0x19299f)
          #2 _taskgo golang/runtime/libgolang.cpp:119 (liblibgolang.so.0.1+0x3f68)
          #3 _test_go_c golang/runtime/libgolang_test_c.c:84 (_golang_test.so+0x13a1c)
          #4 __pyx_pf_6golang_12_golang_test_12test_go_c golang/_golang_test.cpp:3340 (_golang_test.so+0xcbaa)
          #5 __pyx_pw_6golang_12_golang_test_13test_go_c golang/_golang_test.cpp:3305 (_golang_test.so+0xcbaa)
          #6 PyEval_EvalFrameEx <null> (python2.7+0xf68b4)
      
      py37-thread-asan:
      ==22205==ERROR: AddressSanitizer: heap-use-after-free on address 0x607000002cd0 at pc 0x7fd3732a7679 bp 0x7fd3723c8c50 sp 0x7fd3723c8c48
      READ of size 8 at 0x607000002cd0 thread T7
          #0 0x7fd3732a7678 in golang::Sema::acquire() golang/runtime/libgolang.cpp:164
          #1 0x7fd3732a8644 in golang::Mutex::lock() golang/runtime/libgolang.cpp:175
          #2 0x7fd3732a8644 in golang::_chan::close() golang/runtime/libgolang.cpp:754
          #3 0x7fd3724004b2 in golang::chan<golang::structZ>::close() const golang/libgolang.h:323
          #4 0x7fd3724004b2 in operator() golang/runtime/libgolang_test.cpp:262
          #5 0x7fd3724004b2 in __invoke_impl<void, _test_chan_vs_stackdeadwhileparked()::<lambda()>&> /usr/include/c++/8/bits/invoke.h:60
          #6 0x7fd3724004b2 in __invoke<_test_chan_vs_stackdeadwhileparked()::<lambda()>&> /usr/include/c++/8/bits/invoke.h:95
          #7 0x7fd3724004b2 in __call<void> /usr/include/c++/8/functional:400
          #8 0x7fd3724004b2 in operator()<> /usr/include/c++/8/functional:484
          #9 0x7fd3724004b2 in _M_invoke /usr/include/c++/8/bits/std_function.h:297
          #10 0x7fd3723fdc6e in std::function<void ()>::operator()() const /usr/include/c++/8/bits/std_function.h:687
          #11 0x7fd3723fdc6e in operator() golang/libgolang.h:273
          #12 0x7fd3723fdc6e in _FUN golang/libgolang.h:271
          #13 0x62ddf3  (/home/kirr/src/tools/go/pygolang-master/.tox/py37-thread-asan/bin/python3+0x62ddf3)
          #14 0x7fd377393fa2 in start_thread /build/glibc-vjB4T1/glibc-2.28/nptl/pthread_create.c:486
          #15 0x7fd376eda4ce in clone (/lib/x86_64-linux-gnu/libc.so.6+0xf94ce)
      
      0x607000002cd0 is located 16 bytes inside of 72-byte region [0x607000002cc0,0x607000002d08)
      freed by thread T0 here:
          #0 0x7fd377519fb0 in __interceptor_free (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xe8fb0)
          #1 0x7fd372401335 in golang::chan<golang::structZ>::~chan() golang/libgolang.h:292
          #2 0x7fd372401335 in _test_chan_vs_stackdeadwhileparked() golang/runtime/libgolang_test.cpp:222
      
      previously allocated by thread T0 here:
          #0 0x7fd37751a518 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xe9518)
          #1 0x7fd3732a7d0b in zalloc golang/runtime/libgolang.cpp:1185
          #2 0x7fd3732a7d0b in _makechan golang/runtime/libgolang.cpp:413
      
      Thread T7 created by T0 here:
          #0 0x7fd377481db0 in __interceptor_pthread_create (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x50db0)
          #1 0x62df39 in PyThread_start_new_thread (/home/kirr/src/tools/go/pygolang-master/.tox/py37-thread-asan/bin/python3+0x62df39)
      
      SUMMARY: AddressSanitizer: heap-use-after-free golang/runtime/libgolang.cpp:164 in golang::Sema::acquire()
      Shadow bytes around the buggy address:
        0x0c0e7fff8540: fa fa fa fa fd fd fd fd fd fd fd fd fd fa fa fa
        0x0c0e7fff8550: fa fa fd fd fd fd fd fd fd fd fd fa fa fa fa fa
        0x0c0e7fff8560: fd fd fd fd fd fd fd fd fd fd fa fa fa fa fd fd
        0x0c0e7fff8570: fd fd fd fd fd fd fd fa fa fa fa fa fd fd fd fd
        0x0c0e7fff8580: fd fd fd fd fd fa fa fa fa fa fd fd fd fd fd fd
      =>0x0c0e7fff8590: fd fd fd fa fa fa fa fa fd fd[fd]fd fd fd fd fd
        0x0c0e7fff85a0: fd fa fa fa fa fa 00 00 00 00 00 00 00 00 00 fa
        0x0c0e7fff85b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
        0x0c0e7fff85c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
        0x0c0e7fff85d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
        0x0c0e7fff85e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
      Shadow byte legend (one shadow byte represents 8 application bytes):
        Addressable:           00
        Partially addressable: 01 02 03 04 05 06 07
        Heap left redzone:       fa
        Freed heap region:       fd
        Stack left redzone:      f1
        Stack mid redzone:       f2
        Stack right redzone:     f3
        Stack after return:      f5
        Stack use after scope:   f8
        Global redzone:          f9
        Global init order:       f6
        Poisoned by user:        f7
        Container overflow:      fc
        Array cookie:            ac
        Intra object redzone:    bb
        ASan internal:           fe
        Left alloca redzone:     ca
        Right alloca redzone:    cb
      
      ---- 8< ----
      
      The bugs will be addressed in the followup patches.
      4dc1a7f0
    • Kirill Smelkov's avatar
      libgolang: Clarify with_lock wrt covered scope · 78e38690
      Kirill Smelkov authored
      Make it clear which scope is covered by with_lock(mu): instead of
      implicitly having it from with_lock till end of current block
      
      		with_lock(mu);
      		...
      	} // end of current block
      
      make it to be the statement covered by with_lock, as if with_lock was
      e.g. an `if`, for example:
      
      	with_lock(mu)
      		do_something();
      	// mu released here
      
      or
      
      	with_lock(mu) {
      		do_smth1();
      		do_smth2();
      	} // mu released here
      
      This makes the intent in __chanselect2 more clear: it was
      
      	ch->_mu.lock();
      	with_lock(g->_mu);
      		...
      	ch->_mu.unlock();
      
      and semantically human expects g->mu to be released _before_
      ch->_mu.unlock(). However with current with_lock implementation, g->mu
      will be released _after_ ch->_mu.unlock(), which goes against intuition.
      
      -> By reworking with_lock implementation to cover only next statement or
      block of code we make sure that g->_mu will be released _before_
      ch->_mu - the same way as it was until 3b241983 (Port/move channels to
      C/C++/Pyx):
      
      	ch->_mu.lock();
      	with_lock(g->_mu) {
      		...
      	}
      	ch->_mu.unlock();
      78e38690
    • Kirill Smelkov's avatar
      libgolang: Mark classes that we "don't copy" also as "don't move" · 5d72c88c
      Kirill Smelkov authored
      Be on safe side: both aspects - copy and move - are forbidden for all
      those internal classes.
      5d72c88c
  2. 16 Sep, 2019 2 commits
  3. 11 Sep, 2019 4 commits
    • Kirill Smelkov's avatar
      libgolang/thread: Don't ignore PyThread_acquire_lock return · 38f1900b
      Kirill Smelkov authored
      With WAIT_LOCK flag and correct usage PyThread_acquire_lock should never
      fail, but let's be cautious and verify that it indeed succeeds to acquire
      the lock.
      
      The rest of external functions called by thread runtime either have void
      return, or their return is checked.
      38f1900b
    • Kirill Smelkov's avatar
      .gitignore: Update · 48785942
      Kirill Smelkov authored
      - pytest cache
      - pip wheel metadata
      - tags (from ctags)
      - vim swap files
      48785942
    • Kirill Smelkov's avatar
      strconv: Fix thinko in _bstr · 8e5864df
      Kirill Smelkov authored
      In Python, %-formatting needs % operator, not ",".
      8e5864df
    • Kirill Smelkov's avatar
      golang: Mark chan<T> IO methods as const · 3aca691e
      Kirill Smelkov authored
      chan<T> is a pointer type and e.g. send does not change the pointer - it
      only "modifies" channel buffer. Marking appropriate methods as const is
      needed so that `const chan<T>` could be used to send/receive the same
      way as `chan <T>` is used.
      3aca691e
  4. 01 Sep, 2019 1 commit
  5. 29 Aug, 2019 22 commits
    • Kirill Smelkov's avatar
      check-manifest · 59892def
      Kirill Smelkov authored
      As suggested by https://github.com/jayvdb run manifest checker and oops,
      it finds that we forgot to include pyproject.toml for testprog/golang_pyx_user:
      
          missing from sdist:
            golang/pyx/testprog/golang_pyx_user/pyproject.toml
          suggested MANIFEST.in rules:
            recursive-include golang *.toml
      
      -> Fix MANIFEST.in in generic way to include golang/*/*.toml
      
      The bug was not affecting pygolang usage - only golang.pyx.build tests were
      failing for sdist installed pygolang.
      59892def
    • Kirill Smelkov's avatar
      pygolang v0.0.3 · 4ca65816
      Kirill Smelkov authored
      4ca65816
    • Kirill Smelkov's avatar
      Port/move channels to C/C++/Pyx · 3b241983
      Kirill Smelkov authored
      - Move channels implementation to be done in C++ inside libgolang. The
        code and logic is based on previous Python-level channels
        implementation, but the new code is just C++ and does not depend on
        Python nor GIL at all, and so works without GIL if libgolang
        runtime works without GIL(*).
      
        (*) for example "thread" runtime works without GIL, while "gevent" runtime
            acquires GIL on every semaphore acquire.
      
        New channels implementation is located in δ(libgolang.cpp).
      
      - Provide low-level C channels API to the implementation. The low-level
        C API was inspired by Libtask[1] and Plan9/Libthread[2].
      
        [1] Libtask: a Coroutine Library for C and Unix. https://swtch.com/libtask.
        [2] http://9p.io/magic/man2html/2/thread.
      
      - Provide high-level C++ channels API that provides type-safety and
        automatic channel lifetime management.
      
        Overview of C and C++ APIs are in δ(libgolang.h).
      
      - Expose C++ channels API at Pyx level as Cython/nogil API so that Cython
        programs could use channels with ease and without need to care about
        lifetime management and low-level details.
      
        Overview of Cython/nogil channels API is in δ(README.rst) and
        δ(_golang.pxd).
      
      - Turn Python channels to be tiny wrapper around chan<PyObject>.
      
      Implementation note:
      
      - gevent case needs special care because greenlet, which gevent uses,
        swaps coroutine stack from C stack to heap on coroutine park, and
        replaces that space on C stack with stack of activated coroutine
        copied back from heap. This way if an object on g's stack is accessed
        while g is parked it would be memory of another g's stack.
      
        The channels implementation explicitly cares about this issue so that
        stack -> * channel send, or * -> stack channel receive work correctly.
      
        It should be noted that greenlet approach, which it inherits from
        stackless, is not only a bit tricky, but also comes with overhead
        (stack <-> heap copy), and prevents a coroutine to migrate from 1 OS
        thread to another OS thread as that would change addresses of on-stack
        things for that coroutine.
      
        As the latter property prevents to use multiple CPUs even if the
        program / runtime are prepared to work without GIL, it would be more
        logical to change gevent/greenlet to use separate stack for each
        coroutine. That would remove stack <-> heap copy and the need for
        special care in channels implementation for stack - stack sends.
        Such approach should be possible to implement with e.g. swapcontext or
        similar mechanism, and a proof of concept of such work wrapped into
        greenlet-compatible API exists[3]. It would be good if at some point
        there would be a chance to explore such approach in Pygolang context.
      
        [3] https://github.com/python-greenlet/greenlet/issues/113#issuecomment-264529838 and below
      
      Just this patch brings in the following speedup at Python level:
      
       (on i7@2.6GHz)
      
      thread runtime:
      
          name             old time/op  new time/op  delta
          go               20.0µs ± 1%  15.6µs ± 1%  -21.84%  (p=0.000 n=10+10)
          chan             9.37µs ± 4%  2.89µs ± 6%  -69.12%  (p=0.000 n=10+10)
          select           20.2µs ± 4%   3.4µs ± 5%  -83.20%  (p=0.000 n=8+10)
          def              58.0ns ± 0%  60.0ns ± 0%   +3.45%  (p=0.000 n=8+10)
          func_def         43.8µs ± 1%  43.9µs ± 1%     ~     (p=0.796 n=10+10)
          call             62.4ns ± 1%  63.5ns ± 1%   +1.76%  (p=0.001 n=10+10)
          func_call        1.06µs ± 1%  1.05µs ± 1%   -0.63%  (p=0.002 n=10+10)
          try_finally       136ns ± 0%   137ns ± 0%   +0.74%  (p=0.000 n=9+10)
          defer            2.28µs ± 1%  2.33µs ± 1%   +2.34%  (p=0.000 n=10+10)
          workgroup_empty  48.2µs ± 1%  34.1µs ± 2%  -29.18%  (p=0.000 n=9+10)
          workgroup_raise  58.9µs ± 1%  45.5µs ± 1%  -22.74%  (p=0.000 n=10+10)
      
      gevent runtime:
      
          name             old time/op  new time/op  delta
          go               24.7µs ± 1%  15.9µs ± 1%  -35.72%  (p=0.000 n=9+9)
          chan             11.6µs ± 1%   7.3µs ± 1%  -36.74%  (p=0.000 n=10+10)
          select           22.5µs ± 1%  10.4µs ± 1%  -53.73%  (p=0.000 n=10+10)
          def              55.0ns ± 0%  55.0ns ± 0%     ~     (all equal)
          func_def         43.6µs ± 1%  43.6µs ± 1%     ~     (p=0.684 n=10+10)
          call             63.0ns ± 0%  64.0ns ± 0%   +1.59%  (p=0.000 n=10+10)
          func_call        1.06µs ± 1%  1.07µs ± 1%   +0.45%  (p=0.045 n=10+9)
          try_finally       135ns ± 0%   137ns ± 0%   +1.48%  (p=0.000 n=10+10)
          defer            2.31µs ± 1%  2.33µs ± 1%   +0.89%  (p=0.000 n=10+10)
          workgroup_empty  70.2µs ± 0%  55.8µs ± 0%  -20.63%  (p=0.000 n=10+10)
          workgroup_raise  90.3µs ± 0%  70.9µs ± 1%  -21.51%  (p=0.000 n=9+10)
      
      The whole Cython/nogil work - starting from 8fa3c15b (Start using Cython
      and providing Cython/nogil API) to this patch - brings in the following
      speedup at Python level:
      
       (on i7@2.6GHz)
      
      thread runtime:
      
          name             old time/op  new time/op  delta
          go               92.9µs ± 1%  15.6µs ± 1%  -83.16%  (p=0.000 n=10+10)
          chan             13.9µs ± 1%   2.9µs ± 6%  -79.14%  (p=0.000 n=10+10)
          select           29.7µs ± 6%   3.4µs ± 5%  -88.55%  (p=0.000 n=10+10)
          def              57.0ns ± 0%  60.0ns ± 0%   +5.26%  (p=0.000 n=10+10)
          func_def         44.0µs ± 1%  43.9µs ± 1%     ~     (p=0.055 n=10+10)
          call             63.5ns ± 1%  63.5ns ± 1%     ~     (p=1.000 n=10+10)
          func_call        1.06µs ± 0%  1.05µs ± 1%   -1.31%  (p=0.000 n=10+10)
          try_finally       139ns ± 0%   137ns ± 0%   -1.44%  (p=0.000 n=10+10)
          defer            2.36µs ± 1%  2.33µs ± 1%   -1.26%  (p=0.000 n=10+10)
          workgroup_empty  98.4µs ± 1%  34.1µs ± 2%  -65.32%  (p=0.000 n=10+10)
          workgroup_raise   135µs ± 1%    46µs ± 1%  -66.35%  (p=0.000 n=10+10)
      
      gevent runtime:
      
          name             old time/op  new time/op  delta
          go               68.8µs ± 1%  15.9µs ± 1%  -76.91%  (p=0.000 n=10+9)
          chan             14.8µs ± 1%   7.3µs ± 1%  -50.67%  (p=0.000 n=10+10)
          select           32.0µs ± 0%  10.4µs ± 1%  -67.57%  (p=0.000 n=10+10)
          def              58.0ns ± 0%  55.0ns ± 0%   -5.17%  (p=0.000 n=10+10)
          func_def         43.9µs ± 1%  43.6µs ± 1%   -0.53%  (p=0.035 n=10+10)
          call             63.5ns ± 1%  64.0ns ± 0%   +0.79%  (p=0.033 n=10+10)
          func_call        1.08µs ± 1%  1.07µs ± 1%   -1.74%  (p=0.000 n=10+9)
          try_finally       142ns ± 0%   137ns ± 0%   -3.52%  (p=0.000 n=10+10)
          defer            2.32µs ± 1%  2.33µs ± 1%   +0.71%  (p=0.005 n=10+10)
          workgroup_empty  90.3µs ± 0%  55.8µs ± 0%  -38.26%  (p=0.000 n=10+10)
          workgroup_raise   108µs ± 1%    71µs ± 1%  -34.64%  (p=0.000 n=10+10)
      
      This patch is the final patch in series to reach the goal of providing
      channels that could be used in Cython/nogil code.
      
      Cython/nogil channels work is dedicated to the memory of Вера Павловна Супрун[4].
      
      [4] https://navytux.spb.ru/memory/%D0%A2%D1%91%D1%82%D1%8F%20%D0%92%D0%B5%D1%80%D0%B0.pdf#page=3
      3b241983
    • Kirill Smelkov's avatar
      Hook in list.h from Linux · 9efb6575
      Kirill Smelkov authored
      Copy linux/list.h from wendelin.core which copied it from
      util-linux.git which took it from linux.git at LGPL license state.
      
      Here are corresponding links for wendelin.core and util-linux:
      
          wendelin.core@a0f940ad
          https://git.kernel.org/cgit/utils/util-linux/util-linux.git/tree/include/list.h?id=v2.25-165-g9138d6f
      
      Linked lists will be used in channels implementation in the next patch.
      9efb6575
    • Kirill Smelkov's avatar
      libgolang: Add internal semaphores · 69db91bf
      Kirill Smelkov authored
      - Add semaphore alloc/free/acquire/release functionality to libgolang runtime;
      - Implement semaphores for thread and gevent runtimes.
      
        * Thread runtime uses PyThread_acquire_lock/PyThread_release_lock +
          PyThread_acquire_lock/PyThread_release_lock, which, if used
          carefully, do not depend on GIL and on e.g. POSIX are tiny wrappers
          around sem_init(process-private) + sem_post/sem_wait(*).
      
        * Gevent runtime uses geven't Semaphore in Pyx mode.
      
      - Add Sema and Mutex classes that use semaphores provided by a runtime
        in a RAII style.
      - Add with_lock(mu) that mimics `with mu` in Python.
      
      Sema and Mutex will be used in channels implementation in the followup
      patch.
      
      (*) during late testing a bug was found in CPython2 and PyPy semaphore
      implementations on Darwin (technically speaking on POSIX with
      _POSIX_SEMAPHORES undefined). Quoting the patch:
      
          FIXME On Darwin, even though this is considered as POSIX, Python uses
          mutex+condition variable to implement its lock, and, as of 20190828, Py2.7
          implementation, even though similar issue was fixed for Py3 in 2012, contains
          synchronization bug: the condition is signalled after mutex unlock while the
          correct protocol is to signal condition from under mutex:
      
            https://github.com/python/cpython/blob/v2.7.16-127-g0229b56d8c0/Python/thread_pthread.h#L486-L506
            https://github.com/python/cpython/commit/187aa545165d (py3 fix)
      
          PyPy has the same bug for both pypy2 and pypy3:
      
            https://bitbucket.org/pypy/pypy/src/578667b3fef9/rpython/translator/c/src/thread_pthread.c#lines-443:465
            https://bitbucket.org/pypy/pypy/src/5b42890d48c3/rpython/translator/c/src/thread_pthread.c#lines-443:465
      
          This way when Pygolang is used with buggy Python/darwin, the bug leads to
          frequently appearing deadlocks, while e.g. CPython3/darwin works ok.
      
          -> TODO maintain our own semaphore code.
      
      So eventually we'll have push down and maintain our own semaphores,
      at least for platforms we care, not to be beaten by CPython runtime bugs.
      69db91bf
    • Kirill Smelkov's avatar
      golang.pyx: pyselect: Small cosmetics · e4dddf15
      Kirill Smelkov authored
      Move `ch = py{send,recv}.__self__` to right after case __class__ check.
      For now both versions - old and new - can work, but when we'll move
      channel implementations to C the new version will be required to access
      pychan C-level attribute earlier than where ch is currently initialized.
      e4dddf15
    • Kirill Smelkov's avatar
    • Kirill Smelkov's avatar
      golang.pyx: pyselect: * -> py* in logic which analyzes cases · d5e74947
      Kirill Smelkov authored
      For clarity to denote that things work at Python level:
      
          - casev	-> pycasev
          - case	-> pycase
          - recv	-> pyrecv
          - send	-> pysend
      
      Channel object is still denoted as `ch` to reduce noise for when chan IO
      code will be move into libgolang. `ch` will be renamed to `pych` after
      that.
      d5e74947
    • Kirill Smelkov's avatar
      golang: tests: Rework verifying blockforever · b9333e00
      Kirill Smelkov authored
      - put the logic to test-tweak what happens inside _blockforever into
        context manager pypanicWhenBlocked;
      - place this manager in pyx code, where it can later be changed to tweak
        _blockforever at C level.
      b9333e00
    • Kirill Smelkov's avatar
      golang_test.pyx: ch -> pych for Py-level pychan objects · 4166dc65
      Kirill Smelkov authored
      For clarity to distinguish where an object is Python-level channel, or
      (later) a C-level channel.
      4166dc65
    • Kirill Smelkov's avatar
      golang_test.pyx: Switch to cimport pychan · ef076d3a
      Kirill Smelkov authored
      Change `from golang import chan` to `from golang cimport pychan`; add
      type annotations where pychan is used. Using pychan at C level will be
      needed when test code will need to access C-level pychan attributes.
      ef076d3a
    • Kirill Smelkov's avatar
      golang.pyx: Switch pychan from `class` to `cdef class` · 1bcb8297
      Kirill Smelkov authored
      We will need to add C-level attributes to pychan and this requires it to
      become cdef class. The class is exported because at least
      _golang_test.pyx will also need to have access to those attributes.
      
      If we just do `class pychan` -> `cdef class pychan` e.g. the following
      starts to break:
      
          1.venv/local/lib/python2.7/site-packages/py/_path/local.py:701: in pyimport
              __import__(modname)
          golang/__init__.py:174: in <module>
              from ._golang import    \
          golang/_golang.pyx:455: in init golang._golang
              _pychan_send  = _pychan_send.__func__
          E   AttributeError: 'method_descriptor' object has no attribute '__func__'
      
      and
      
          golang/_golang.pyx:513: in golang._golang.pyselect
              if im_class(recv) is not pychan:
          _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
      
          f = <built-in method recv of golang._golang.pychan object at 0x7f7055e57cc8>
      
              def im_class(f):
          >       return f.im_class
          E       AttributeError: 'builtin_function_or_method' object has no attribute 'im_class'
      
          golang/_pycompat.py:28: AttributeError
      
      This is probably because for `cdef class` methods Cython does not
      emulate full method bindings the same way as Python does.  Anyway we can
      check which method is passed to pyselect by chanop.__name__ or by
      inspecting PyCFunction directly. And not having method binding wrapper
      should only remove a bit of overhead.
      
      So we are ok with reworking send/recv chanop detection, and since
      this way im_class provided by golang._pycompat becomes unused, it is
      also removed.
      
      The timings are probably within noise:
      
       (on i7@2.6GHz)
      
      thread runtime:
      
          name             old time/op  new time/op  delta
          go               21.7µs ± 1%  20.0µs ± 1%  -7.60%  (p=0.000 n=10+10)
          chan             9.91µs ± 4%  9.37µs ± 4%  -5.39%  (p=0.000 n=10+10)
          select           19.2µs ± 4%  20.2µs ± 4%  +5.62%  (p=0.001 n=9+8)
          def              58.0ns ± 0%  58.0ns ± 0%    ~     (all equal)
          func_def         44.4µs ± 0%  43.8µs ± 1%  -1.22%  (p=0.000 n=10+10)
          call             63.0ns ± 0%  62.4ns ± 1%  -0.95%  (p=0.011 n=10+10)
          func_call        1.05µs ± 1%  1.06µs ± 1%    ~     (p=0.059 n=10+10)
          try_finally       135ns ± 0%   136ns ± 0%  +0.74%  (p=0.000 n=10+9)
          defer            2.36µs ± 1%  2.28µs ± 1%  -3.59%  (p=0.000 n=10+10)
          workgroup_empty  49.0µs ± 1%  48.2µs ± 1%  -1.63%  (p=0.000 n=10+9)
          workgroup_raise  62.6µs ± 1%  58.9µs ± 1%  -5.96%  (p=0.000 n=10+10)
      
      gevent runtime:
      
          name             old time/op  new time/op  delta
          go               21.7µs ± 1%  20.5µs ± 1%  -5.33%  (p=0.000 n=10+9)
          chan             9.91µs ± 4%  9.72µs ± 5%    ~     (p=0.190 n=10+10)
          select           19.2µs ± 4%  19.5µs ±14%    ~     (p=0.968 n=9+10)
          def              58.0ns ± 0%  58.0ns ± 0%    ~     (all equal)
          func_def         44.4µs ± 0%  45.4µs ± 1%  +2.23%  (p=0.000 n=10+10)
          call             63.0ns ± 0%  64.0ns ± 0%  +1.59%  (p=0.000 n=10+10)
          func_call        1.05µs ± 1%  1.06µs ± 0%  +0.65%  (p=0.002 n=10+10)
          try_finally       135ns ± 0%   137ns ± 0%  +1.48%  (p=0.000 n=10+10)
          defer            2.36µs ± 1%  2.38µs ± 1%  +0.72%  (p=0.006 n=10+10)
          workgroup_empty  49.0µs ± 1%  48.2µs ± 1%  -1.65%  (p=0.000 n=10+10)
          workgroup_raise  62.6µs ± 1%  60.3µs ± 1%  -3.69%  (p=0.000 n=10+10)
      1bcb8297
    • Kirill Smelkov's avatar
      golang_test.pyx: Rename moved channel utilities * -> py* · a0714b8e
      Kirill Smelkov authored
      For consistency to denote that this functions work at Python level:
      
          - len_sendq    -> pylen_sendq
          - len_recvq    -> pylen_recvq
          - waitBlocked  -> pywaitBlocked
      a0714b8e
    • Kirill Smelkov's avatar
      golang: tests: Move channel test utilities from golang_test.py -> _golang_test.pyx · a508be9a
      Kirill Smelkov authored
      Plain test code movement with s/panic/pypanic/ as in golang.pyx panic is
      already there and means semantically different thing. We need this code to
      live in pyx world, because when channels implementation will be moved to
      C, this utilities will need to be adjusted in a way that is not possible
      to do from Python.
      a508be9a
    • Kirill Smelkov's avatar
      golang.pyx: pychan: return cosmetics · 790189e3
      Kirill Smelkov authored
      Denote what a method returns via `# -> ...` suffix.
      790189e3
    • Kirill Smelkov's avatar
      golang.pyx: pychan: self -> ch · 7e55394d
      Kirill Smelkov authored
      Use `ch` instead of `self` for pychan methods. This aligns with how
      (py)chan objects are currently denoted in (py)select and will reduce the
      difference when chan code is moved into libgolang. We are sticking to Go
      convention here.
      
      After the code with channels implementation is moved into libgolang, the
      rest bits in golang.pyx will be changed to refer to pychan objects as
      pych for clarity.
      7e55394d
    • Kirill Smelkov's avatar
      golang.pyx: Rename moved channel bits * -> py* · 311df9f1
      Kirill Smelkov authored
      To denote that this function/classes work at Python level:
      
          - chan    -> pychan
          - select  -> pyselect
          - default -> pydefault
          - nilchan -> pynilchan
      311df9f1
    • Kirill Smelkov's avatar
      golang: Move channels implementation from golang.py to golang.pyx · 83259a1b
      Kirill Smelkov authored
      Plain code movement with just s/panic/pypanic/ as in golang.pyx panic is
      aleady there and means semantically different thing. Moved code, even
      though it lives in golang.pyx, is still Python code and requires Python
      runtime and GIL. We'll be splitting channels implementation into nogil
      world in the following patches.
      
      Just plain movement to Cython brings the following speedup:
      
       (on i7@2.6GHz)
      
      thread runtime:
      
          name             old time/op  new time/op  delta
          go               26.6µs ± 1%  21.7µs ± 1%  -18.54%  (p=0.000 n=10+10)
          chan             13.7µs ± 1%   9.9µs ± 4%  -27.80%  (p=0.000 n=10+10)
          select           29.3µs ± 2%  19.2µs ± 4%  -34.65%  (p=0.000 n=9+9)
          def              55.0ns ± 0%  58.0ns ± 0%   +5.45%  (p=0.000 n=10+10)
          func_def         44.0µs ± 1%  44.4µs ± 0%   +0.72%  (p=0.002 n=10+10)
          call             64.0ns ± 0%  63.0ns ± 0%   -1.56%  (p=0.002 n=8+10)
          func_call        1.09µs ± 1%  1.05µs ± 1%   -2.96%  (p=0.000 n=10+10)
          try_finally       139ns ± 2%   135ns ± 0%   -2.60%  (p=0.000 n=10+10)
          defer            2.36µs ± 1%  2.36µs ± 1%     ~     (p=0.617 n=10+10)
          workgroup_empty  58.1µs ± 1%  49.0µs ± 1%  -15.61%  (p=0.000 n=10+10)
          workgroup_raise  72.7µs ± 1%  62.6µs ± 1%  -13.88%  (p=0.000 n=10+10)
      
      gevent runtime:
      
          name             old time/op  new time/op  delta
          go               28.6µs ± 0%  25.4µs ± 0%  -11.20%  (p=0.000 n=8+9)
          chan             15.8µs ± 1%  12.2µs ± 1%  -22.62%  (p=0.000 n=10+10)
          select           33.1µs ± 1%  23.3µs ± 2%  -29.60%  (p=0.000 n=10+10)
          def              55.0ns ± 0%  56.0ns ± 0%   +1.82%  (p=0.000 n=10+10)
          func_def         44.4µs ± 2%  43.0µs ± 1%   -3.06%  (p=0.000 n=10+9)
          call             64.0ns ± 2%  69.0ns ± 0%   +7.81%  (p=0.000 n=10+10)
          func_call        1.06µs ± 0%  1.06µs ± 1%     ~     (p=0.913 n=8+9)
          try_finally       136ns ± 0%   139ns ± 0%   +2.21%  (p=0.000 n=9+10)
          defer            2.29µs ± 1%  2.38µs ± 2%   +3.58%  (p=0.000 n=10+10)
          workgroup_empty  73.8µs ± 1%  70.5µs ± 1%   -4.48%  (p=0.000 n=10+10)
          workgroup_raise  94.1µs ± 0%  90.6µs ± 0%   -3.69%  (p=0.000 n=10+10)
      83259a1b
    • Kirill Smelkov's avatar
      pyx api: Provide go · f971a2a8
      Kirill Smelkov authored
      - Add go functionality to libgolang runtime;
      - Implement go for thread and gevent runtimes.
      
        * Thread runtime uses PyThread_start_new_thread which, if used
          carefully, does not depend on Python GIL and on e.g. POSIX reduces to
          tiny wrapper around pthread_create.
      
        * Gevent runtime uses gevent's Greenlet in Pyx mode. This turns
          gevent to be a build-time dependency.
      
      - Provide low-level _taskgo in C client API;
      - Provide type-safe C++-level go wrapper over _taskgo;
      - Switch golang.go from py implementation into Pyx wrapper over
        Pyx/nogil API.
      
      This is the first patch that adds Pyx/C++/C-level unit tests and hooks
      them into golang_test.py .
      
      This patch brings the following speedup to Python-level interface:
      
       (on i7@2.6GHz)
      
      thread runtime:
      
          name             old time/op  new time/op  delta
          go               93.0µs ± 1%  26.6µs ± 1%  -71.41%  (p=0.000 n=10+10)
          chan             13.6µs ± 2%  13.7µs ± 1%     ~     (p=0.280 n=10+10)
          select           29.9µs ± 4%  29.3µs ± 2%   -1.89%  (p=0.017 n=10+9)
          def              61.0ns ± 0%  55.0ns ± 0%   -9.84%  (p=0.000 n=10+10)
          func_def         43.8µs ± 1%  44.0µs ± 1%   +0.66%  (p=0.006 n=10+10)
          call             62.5ns ± 1%  64.0ns ± 0%   +2.40%  (p=0.000 n=10+8)
          func_call        1.06µs ± 1%  1.09µs ± 1%   +2.72%  (p=0.000 n=10+10)
          try_finally       137ns ± 0%   139ns ± 2%   +1.17%  (p=0.033 n=10+10)
          defer            2.34µs ± 1%  2.36µs ± 1%   +0.84%  (p=0.015 n=10+10)
          workgroup_empty  96.1µs ± 1%  58.1µs ± 1%  -39.55%  (p=0.000 n=10+10)
          workgroup_raise   135µs ± 1%    73µs ± 1%  -45.97%  (p=0.000 n=10+10)
      
      gevent runtime:
      
          name             old time/op  new time/op  delta
          go               68.8µs ± 1%  28.6µs ± 0%  -58.47%  (p=0.000 n=10+8)
          chan             14.8µs ± 1%  15.8µs ± 1%   +6.19%  (p=0.000 n=10+10)
          select           32.0µs ± 0%  33.1µs ± 1%   +3.25%  (p=0.000 n=10+10)
          def              58.0ns ± 0%  55.0ns ± 0%   -5.17%  (p=0.000 n=10+10)
          func_def         43.9µs ± 1%  44.4µs ± 2%   +1.20%  (p=0.007 n=10+10)
          call             63.5ns ± 1%  64.0ns ± 2%     ~     (p=0.307 n=10+10)
          func_call        1.08µs ± 1%  1.06µs ± 0%   -2.55%  (p=0.000 n=10+8)
          try_finally       142ns ± 0%   136ns ± 0%   -4.23%  (p=0.000 n=10+9)
          defer            2.32µs ± 1%  2.29µs ± 1%   -0.96%  (p=0.000 n=10+10)
          workgroup_empty  90.3µs ± 0%  73.8µs ± 1%  -18.29%  (p=0.000 n=10+10)
          workgroup_raise   108µs ± 1%    94µs ± 0%  -13.29%  (p=0.000 n=10+10)
      
      (small changes are probably within noise; "go" and "workgroup_*" should be
      representative)
      f971a2a8
    • Kirill Smelkov's avatar
      pyx.build: Allow to combine C and C++ sources in one extension · 7ae8c4f3
      Kirill Smelkov authored
      The next patch will add `go` to Pyx API and correspondingly C, C++ and Pyx
      level tests for it that will go into _golang_test.pyx extension. For
      C-level test we'll use C source file - to verify that libgolang.h could
      be used by C projects with C compiler, while for C++ and Pyx-level tests
      the sources will be in C++. Thus _golang_test.so will be build from both
      C and C++ sources.
      
      This creates a problem: distutils / setuptools use the _same_ compiler
      to compile both C and C++ sources and only use C++ compiler at link
      stage. Thus, as it is not possible to tune compiler that is used only
      for C++ sources, and also as it is not possible to provide per-source
      flags, when compiling C-level test, the compiler will be invoked with
      `-std=c++11` option that we inject. Gcc tolerates that and only prints a
      warning, but Clang considers that an error and gives:
      
      	error: invalid argument '-std=c++11' not allowed with 'C'`
      
      A proper fix would be to change the build system from distutils to
      something more flexible that uses C++ compiler for C++ sources and C
      compiler for C sources and allows to tune per-unit flags. However it is
      not a small step at this stage.
      
      -> Use workaround and tweak options that are used when compiling sources
      depending on whether it is C or C++.
      7ae8c4f3
    • Kirill Smelkov's avatar
      pyx api: Provide sleep · ce8152a2
      Kirill Smelkov authored
      - Add sleep functionality to libgolang runtime;
      - Implement sleep for thread and gevent runtimes. Thread runtime
        implements sleep independently of GIL, but only for POSIX for now;
      - Switch golang.time py module into using golang.time pyx module.
      
      As we are adding sleep, related functionality to query system about
      "what is current time?" is also added.
      ce8152a2
    • Kirill Smelkov's avatar
      libgolang: Introduce runtimes · ad00be70
      Kirill Smelkov authored
      Libgolang will be generic library and it will adapt itself to particular
      execution environment by way of runtime plugin. This commit introduces
      stubs for two such runtimes - "thread" and "gevent" - and initializes
      libgolang with particular runtime depending on whether golang is
      imported with gevent preactivated or not.
      
      The runtimes themselves are empty at this step. We'll be adding runtime
      functionality in the following patches.
      ad00be70