ThreadSanitizer reports data race in AtomicCell::compare_exchange if it is not lock-free

[taiki-e]

Run the following command:

RUSTFLAGS="-Z sanitizer=thread --cfg crossbeam_sanitize" \
cargo test -Z build-std --release --target x86_64-unknown-linux-gnu -p crossbeam-channel --test tick -- --test-threads=1

ThreadSanitizer reports data race:

output

     Running target/x86_64-unknown-linux-gnu/release/deps/tick-ad2808fb9d249901

running 12 tests
test capacity ... ok
test fairness ... ok
test fairness_duplicates ... ok
test fire ... ok
test intervals ... ok
test len_empty_full ... ok
test recv ... ok
test recv_race ... ok
==================
WARNING: ThreadSanitizer: data race (pid=28791)
  Write of size 8 at 0x7b0c000000d0 by thread T2:
    #0 crossbeam_utils::atomic::atomic_cell::AtomicCell<T>::compare_exchange :? (tick-ad2808fb9d249901+0xa35b3)
    #1 crossbeam_channel::flavors::tick::Channel::try_recv tick.1mqhsnvi-cgu.1:? (tick-ad2808fb9d249901+0x97d42)
    #2 <crossbeam_channel::channel::Receiver<T> as crossbeam_channel::select::SelectHandle>::try_select ??:? (tick-ad2808fb9d249901+0x95652)
    #3 crossbeam_channel::select::run_select ??:? (tick-ad2808fb9d249901+0x11030b)
    #4 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.6:? (tick-ad2808fb9d249901+0xa6446)
    #5 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ad97)
    #6 _ZN3std9panicking3try7do_call17hc5c870465619690dE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9ca40)
    #7 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #8 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c638)
    #9 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.12:? (tick-ad2808fb9d249901+0x999a5)
    #10 <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once :? (tick-ad2808fb9d249901+0x12f93b)
    #11 std::sys::unix::thread::Thread::new::thread_start std.4y1imyn0-cgu.8:? (tick-ad2808fb9d249901+0x1562fc)

  Previous read of size 8 at 0x7b0c000000d0 by thread T1:
    #0 crossbeam_utils::atomic::atomic_cell::AtomicCell<T>::load :? (tick-ad2808fb9d249901+0xa3719)
    #1 <crossbeam_channel::channel::Receiver<T> as crossbeam_channel::select::SelectHandle>::register ??:? (tick-ad2808fb9d249901+0x96c8a)
    #2 crossbeam_channel::context::Context::with::{{closure}} crossbeam_channel.dnclaqj4-cgu.0:? (tick-ad2808fb9d249901+0x10f60b)
    #3 crossbeam_channel::select::run_select ??:? (tick-ad2808fb9d249901+0x1100f1)
    #4 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.6:? (tick-ad2808fb9d249901+0xa5d96)
    #5 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ad97)
    #6 _ZN3std9panicking3try7do_call17h5380285a5761ee30E.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9c7e0)
    #7 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #8 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c558)
    #9 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.12:? (tick-ad2808fb9d249901+0x99c85)
    #10 <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once :? (tick-ad2808fb9d249901+0x12f93b)
    #11 std::sys::unix::thread::Thread::new::thread_start std.4y1imyn0-cgu.8:? (tick-ad2808fb9d249901+0x1562fc)

  Location is heap block of size 48 at 0x7b0c000000c0 allocated by main thread:
    #0 malloc /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:652 (tick-ad2808fb9d249901+0x1f834)
    #1 __rdl_alloc :? (tick-ad2808fb9d249901+0x135f8c)
    #2 crossbeam_channel::channel::tick ??:? (tick-ad2808fb9d249901+0x111665)
    #3 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94564)
    #4 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #5 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #6 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #7 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #8 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #9 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #10 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #11 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #12 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #13 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #14 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #15 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #16 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #17 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #18 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #19 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #20 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #21 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #22 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #23 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #24 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #25 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #26 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #27 main ??:? (tick-ad2808fb9d249901+0x95458)
    #28 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #29 __libc_start_main ??:? (libc.so.6+0x21bf6)

  Thread T2 (tid=28797, running) created by main thread at:
    #0 pthread_create /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:966 (tick-ad2808fb9d249901+0x20deb)
    #1 std::sys::unix::thread::Thread::new ??:? (tick-ad2808fb9d249901+0x155f10)
    #2 std::thread::Builder::spawn :? (tick-ad2808fb9d249901+0x98e4b)
    #3 crossbeam_utils::thread::Scope::spawn :? (tick-ad2808fb9d249901+0xa40cc)
    #4 _ZN3std9panicking3try7do_call17h9bd19dcafdeee06fE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9c9da)
    #5 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #6 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c719)
    #7 crossbeam_utils::thread::scope :? (tick-ad2808fb9d249901+0xa4c8a)
    #8 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94599)
    #9 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #10 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #11 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #12 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #13 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #14 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #15 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #16 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #17 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #18 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #19 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #20 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #21 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #22 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #23 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #24 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #25 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #26 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #27 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #28 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #29 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #30 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #31 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #32 main ??:? (tick-ad2808fb9d249901+0x95458)
    #33 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #34 __libc_start_main ??:? (libc.so.6+0x21bf6)

  Thread T1 (tid=28796, running) created by main thread at:
    #0 pthread_create /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:966 (tick-ad2808fb9d249901+0x20deb)
    #1 std::sys::unix::thread::Thread::new ??:? (tick-ad2808fb9d249901+0x155f10)
    #2 std::thread::Builder::spawn :? (tick-ad2808fb9d249901+0x9929b)
    #3 crossbeam_utils::thread::Scope::spawn :? (tick-ad2808fb9d249901+0xa471c)
    #4 _ZN3std9panicking3try7do_call17h9bd19dcafdeee06fE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9c9bd)
    #5 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #6 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c719)
    #7 crossbeam_utils::thread::scope :? (tick-ad2808fb9d249901+0xa4c8a)
    #8 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94599)
    #9 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #10 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #11 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #12 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #13 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #14 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #15 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #16 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #17 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #18 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #19 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #20 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #21 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #22 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #23 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #24 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #25 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #26 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #27 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #28 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #29 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #30 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #31 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #32 main ??:? (tick-ad2808fb9d249901+0x95458)
    #33 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #34 __libc_start_main ??:? (libc.so.6+0x21bf6)

SUMMARY: ThreadSanitizer: data race :? in crossbeam_utils::atomic::atomic_cell::AtomicCell<T>::compare_exchange
==================
==================
WARNING: ThreadSanitizer: data race (pid=28791)
  Write of size 8 at 0x7b0c000000d8 by thread T2:
    #0 crossbeam_utils::atomic::atomic_cell::AtomicCell<T>::compare_exchange :? (tick-ad2808fb9d249901+0xa35c4)
    #1 crossbeam_channel::flavors::tick::Channel::try_recv tick.1mqhsnvi-cgu.1:? (tick-ad2808fb9d249901+0x97d42)
    #2 <crossbeam_channel::channel::Receiver<T> as crossbeam_channel::select::SelectHandle>::try_select ??:? (tick-ad2808fb9d249901+0x95652)
    #3 crossbeam_channel::select::run_select ??:? (tick-ad2808fb9d249901+0x11030b)
    #4 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.6:? (tick-ad2808fb9d249901+0xa6446)
    #5 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ad97)
    #6 _ZN3std9panicking3try7do_call17hc5c870465619690dE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9ca40)
    #7 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #8 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c638)
    #9 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.12:? (tick-ad2808fb9d249901+0x999a5)
    #10 <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once :? (tick-ad2808fb9d249901+0x12f93b)
    #11 std::sys::unix::thread::Thread::new::thread_start std.4y1imyn0-cgu.8:? (tick-ad2808fb9d249901+0x1562fc)

  Previous read of size 8 at 0x7b0c000000d8 by thread T1:
    [failed to restore the stack]

  Location is heap block of size 48 at 0x7b0c000000c0 allocated by main thread:
    #0 malloc /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:652 (tick-ad2808fb9d249901+0x1f834)
    #1 __rdl_alloc :? (tick-ad2808fb9d249901+0x135f8c)
    #2 crossbeam_channel::channel::tick ??:? (tick-ad2808fb9d249901+0x111665)
    #3 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94564)
    #4 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #5 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #6 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #7 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #8 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #9 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #10 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #11 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #12 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #13 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #14 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #15 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #16 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #17 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #18 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #19 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #20 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #21 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #22 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #23 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #24 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #25 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #26 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #27 main ??:? (tick-ad2808fb9d249901+0x95458)
    #28 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #29 __libc_start_main ??:? (libc.so.6+0x21bf6)

  Thread T2 (tid=28797, running) created by main thread at:
    #0 pthread_create /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:966 (tick-ad2808fb9d249901+0x20deb)
    #1 std::sys::unix::thread::Thread::new ??:? (tick-ad2808fb9d249901+0x155f10)
    #2 std::thread::Builder::spawn :? (tick-ad2808fb9d249901+0x98e4b)
    #3 crossbeam_utils::thread::Scope::spawn :? (tick-ad2808fb9d249901+0xa40cc)
    #4 _ZN3std9panicking3try7do_call17h9bd19dcafdeee06fE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9c9da)
    #5 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #6 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c719)
    #7 crossbeam_utils::thread::scope :? (tick-ad2808fb9d249901+0xa4c8a)
    #8 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94599)
    #9 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #10 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #11 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #12 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #13 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #14 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #15 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #16 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #17 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #18 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #19 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #20 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #21 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #22 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #23 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #24 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #25 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #26 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #27 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #28 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #29 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #30 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #31 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #32 main ??:? (tick-ad2808fb9d249901+0x95458)
    #33 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #34 __libc_start_main ??:? (libc.so.6+0x21bf6)

  Thread T1 (tid=28796, running) created by main thread at:
    #0 pthread_create /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:966 (tick-ad2808fb9d249901+0x20deb)
    #1 std::sys::unix::thread::Thread::new ??:? (tick-ad2808fb9d249901+0x155f10)
    #2 std::thread::Builder::spawn :? (tick-ad2808fb9d249901+0x9929b)
    #3 crossbeam_utils::thread::Scope::spawn :? (tick-ad2808fb9d249901+0xa471c)
    #4 _ZN3std9panicking3try7do_call17h9bd19dcafdeee06fE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9c9bd)
    #5 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #6 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c719)
    #7 crossbeam_utils::thread::scope :? (tick-ad2808fb9d249901+0xa4c8a)
    #8 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94599)
    #9 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #10 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #11 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #12 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #13 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #14 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #15 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #16 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #17 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #18 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #19 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #20 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #21 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #22 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #23 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #24 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #25 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #26 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #27 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #28 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #29 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #30 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #31 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #32 main ??:? (tick-ad2808fb9d249901+0x95458)
    #33 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #34 __libc_start_main ??:? (libc.so.6+0x21bf6)

SUMMARY: ThreadSanitizer: data race :? in crossbeam_utils::atomic::atomic_cell::AtomicCell<T>::compare_exchange
==================
==================
WARNING: ThreadSanitizer: data race (pid=28791)
  Write of size 8 at 0x7b0c00000100 by thread T2:
    #0 crossbeam_utils::atomic::atomic_cell::AtomicCell<T>::compare_exchange :? (tick-ad2808fb9d249901+0xa35b3)
    #1 crossbeam_channel::flavors::tick::Channel::try_recv tick.1mqhsnvi-cgu.1:? (tick-ad2808fb9d249901+0x97d42)
    #2 <crossbeam_channel::channel::Receiver<T> as crossbeam_channel::select::SelectHandle>::try_select ??:? (tick-ad2808fb9d249901+0x95652)
    #3 crossbeam_channel::select::run_select ??:? (tick-ad2808fb9d249901+0x10ff3f)
    #4 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.6:? (tick-ad2808fb9d249901+0xa6446)
    #5 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ad97)
    #6 _ZN3std9panicking3try7do_call17hc5c870465619690dE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9ca40)
    #7 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #8 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c638)
    #9 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.12:? (tick-ad2808fb9d249901+0x999a5)
    #10 <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once :? (tick-ad2808fb9d249901+0x12f93b)
    #11 std::sys::unix::thread::Thread::new::thread_start std.4y1imyn0-cgu.8:? (tick-ad2808fb9d249901+0x1562fc)

  Previous read of size 8 at 0x7b0c00000100 by thread T1:
    [failed to restore the stack]

  Location is heap block of size 48 at 0x7b0c000000f0 allocated by main thread:
    #0 malloc /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:652 (tick-ad2808fb9d249901+0x1f834)
    #1 __rdl_alloc :? (tick-ad2808fb9d249901+0x135f8c)
    #2 crossbeam_channel::channel::tick ??:? (tick-ad2808fb9d249901+0x111665)
    #3 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94533)
    #4 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #5 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #6 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #7 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #8 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #9 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #10 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #11 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #12 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #13 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #14 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #15 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #16 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #17 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #18 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #19 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #20 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #21 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #22 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #23 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #24 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #25 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #26 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #27 main ??:? (tick-ad2808fb9d249901+0x95458)
    #28 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #29 __libc_start_main ??:? (libc.so.6+0x21bf6)

  Thread T2 (tid=28797, running) created by main thread at:
    #0 pthread_create /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:966 (tick-ad2808fb9d249901+0x20deb)
    #1 std::sys::unix::thread::Thread::new ??:? (tick-ad2808fb9d249901+0x155f10)
    #2 std::thread::Builder::spawn :? (tick-ad2808fb9d249901+0x98e4b)
    #3 crossbeam_utils::thread::Scope::spawn :? (tick-ad2808fb9d249901+0xa40cc)
    #4 _ZN3std9panicking3try7do_call17h9bd19dcafdeee06fE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9c9da)
    #5 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #6 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c719)
    #7 crossbeam_utils::thread::scope :? (tick-ad2808fb9d249901+0xa4c8a)
    #8 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94599)
    #9 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #10 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #11 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #12 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #13 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #14 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #15 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #16 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #17 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #18 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #19 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #20 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #21 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #22 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #23 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #24 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #25 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #26 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #27 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #28 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #29 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #30 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #31 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #32 main ??:? (tick-ad2808fb9d249901+0x95458)
    #33 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #34 __libc_start_main ??:? (libc.so.6+0x21bf6)

  Thread T1 (tid=28796, running) created by main thread at:
    #0 pthread_create /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:966 (tick-ad2808fb9d249901+0x20deb)
    #1 std::sys::unix::thread::Thread::new ??:? (tick-ad2808fb9d249901+0x155f10)
    #2 std::thread::Builder::spawn :? (tick-ad2808fb9d249901+0x9929b)
    #3 crossbeam_utils::thread::Scope::spawn :? (tick-ad2808fb9d249901+0xa471c)
    #4 _ZN3std9panicking3try7do_call17h9bd19dcafdeee06fE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9c9bd)
    #5 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #6 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c719)
    #7 crossbeam_utils::thread::scope :? (tick-ad2808fb9d249901+0xa4c8a)
    #8 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94599)
    #9 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #10 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #11 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #12 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #13 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #14 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #15 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #16 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #17 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #18 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #19 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #20 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #21 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #22 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #23 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #24 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #25 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #26 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #27 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #28 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #29 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #30 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #31 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #32 main ??:? (tick-ad2808fb9d249901+0x95458)
    #33 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #34 __libc_start_main ??:? (libc.so.6+0x21bf6)

SUMMARY: ThreadSanitizer: data race :? in crossbeam_utils::atomic::atomic_cell::AtomicCell<T>::compare_exchange
==================
==================
WARNING: ThreadSanitizer: data race (pid=28791)
  Write of size 8 at 0x7b0c00000108 by thread T2:
    #0 crossbeam_utils::atomic::atomic_cell::AtomicCell<T>::compare_exchange :? (tick-ad2808fb9d249901+0xa35c4)
    #1 crossbeam_channel::flavors::tick::Channel::try_recv tick.1mqhsnvi-cgu.1:? (tick-ad2808fb9d249901+0x97d42)
    #2 <crossbeam_channel::channel::Receiver<T> as crossbeam_channel::select::SelectHandle>::try_select ??:? (tick-ad2808fb9d249901+0x95652)
    #3 crossbeam_channel::select::run_select ??:? (tick-ad2808fb9d249901+0x10ff3f)
    #4 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.6:? (tick-ad2808fb9d249901+0xa6446)
    #5 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ad97)
    #6 _ZN3std9panicking3try7do_call17hc5c870465619690dE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9ca40)
    #7 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #8 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c638)
    #9 core::ops::function::FnOnce::call_once{{vtable-shim}} tick.1mqhsnvi-cgu.12:? (tick-ad2808fb9d249901+0x999a5)
    #10 <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once :? (tick-ad2808fb9d249901+0x12f93b)
    #11 std::sys::unix::thread::Thread::new::thread_start std.4y1imyn0-cgu.8:? (tick-ad2808fb9d249901+0x1562fc)

  Previous read of size 8 at 0x7b0c00000108 by thread T1:
    [failed to restore the stack]

  Location is heap block of size 48 at 0x7b0c000000f0 allocated by main thread:
    #0 malloc /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:652 (tick-ad2808fb9d249901+0x1f834)
    #1 __rdl_alloc :? (tick-ad2808fb9d249901+0x135f8c)
    #2 crossbeam_channel::channel::tick ??:? (tick-ad2808fb9d249901+0x111665)
    #3 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94533)
    #4 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #5 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #6 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #7 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #8 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #9 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #10 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #11 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #12 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #13 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #14 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #15 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #16 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #17 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #18 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #19 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #20 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #21 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #22 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #23 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #24 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #25 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #26 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #27 main ??:? (tick-ad2808fb9d249901+0x95458)
    #28 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #29 __libc_start_main ??:? (libc.so.6+0x21bf6)

  Thread T2 (tid=28797, running) created by main thread at:
    #0 pthread_create /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:966 (tick-ad2808fb9d249901+0x20deb)
    #1 std::sys::unix::thread::Thread::new ??:? (tick-ad2808fb9d249901+0x155f10)
    #2 std::thread::Builder::spawn :? (tick-ad2808fb9d249901+0x98e4b)
    #3 crossbeam_utils::thread::Scope::spawn :? (tick-ad2808fb9d249901+0xa40cc)
    #4 _ZN3std9panicking3try7do_call17h9bd19dcafdeee06fE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9c9da)
    #5 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #6 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c719)
    #7 crossbeam_utils::thread::scope :? (tick-ad2808fb9d249901+0xa4c8a)
    #8 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94599)
    #9 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #10 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #11 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #12 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #13 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #14 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #15 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #16 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #17 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #18 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #19 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #20 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #21 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #22 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #23 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #24 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #25 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #26 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #27 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #28 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #29 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #30 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #31 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #32 main ??:? (tick-ad2808fb9d249901+0x95458)
    #33 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #34 __libc_start_main ??:? (libc.so.6+0x21bf6)

  Thread T1 (tid=28796, running) created by main thread at:
    #0 pthread_create /rustc/llvm/src/llvm-project/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:966 (tick-ad2808fb9d249901+0x20deb)
    #1 std::sys::unix::thread::Thread::new ??:? (tick-ad2808fb9d249901+0x155f10)
    #2 std::thread::Builder::spawn :? (tick-ad2808fb9d249901+0x9929b)
    #3 crossbeam_utils::thread::Scope::spawn :? (tick-ad2808fb9d249901+0xa471c)
    #4 _ZN3std9panicking3try7do_call17h9bd19dcafdeee06fE.llvm.8341137377273167841 ??:? (tick-ad2808fb9d249901+0x9c9bd)
    #5 __rust_try.llvm.8341137377273167841 :? (tick-ad2808fb9d249901+0x9d11c)
    #6 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x9c719)
    #7 crossbeam_utils::thread::scope :? (tick-ad2808fb9d249901+0xa4c8a)
    #8 core::ops::function::FnOnce::call_once tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x94599)
    #9 test::__rust_begin_short_backtrace test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3d93)
    #10 core::ops::function::FnOnce::call_once{{vtable-shim}} test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xad7bd)
    #11 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once :? (tick-ad2808fb9d249901+0xd2cf3)
    #12 _ZN3std9panicking3try7do_call17h4674e2ca3cde87d0E.llvm.15501654358489514047 ??:? (tick-ad2808fb9d249901+0xe50d0)
    #13 __rust_try.llvm.15501654358489514047 :? (tick-ad2808fb9d249901+0xe75dc)
    #14 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0xd3692)
    #15 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #16 test::run_test_in_process :? (tick-ad2808fb9d249901+0xb4009)
    #17 test::run_test::run_test_inner test.dt4s8qfr-cgu.14:? (tick-ad2808fb9d249901+0xb3b78)
    #18 test::run_test ??:? (tick-ad2808fb9d249901+0xb31ce)
    #19 test::run_tests :? (tick-ad2808fb9d249901+0xb082c)
    #20 test::console::run_tests_console ??:? (tick-ad2808fb9d249901+0xc50ea)
    #21 test::test_main ??:? (tick-ad2808fb9d249901+0xaf51e)
    #22 test::test_main_static ??:? (tick-ad2808fb9d249901+0xaf74e)
    #23 tick::main tick.1mqhsnvi-cgu.0:? (tick-ad2808fb9d249901+0x953ec)
    #24 std::sys_common::backtrace::__rust_begin_short_backtrace :? (tick-ad2808fb9d249901+0x9ae13)
    #25 _ZN3std2rt10lang_start28_$u7b$$u7b$closure$u7d$$u7d$17heb647d3d546ba7ffE.llvm.16568285768813341694 ??:? (tick-ad2808fb9d249901+0x986ed)
    #26 _ZN3std9panicking3try7do_call17hc16ff548790882f6E.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14ac85)
    #27 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #28 __rust_try.llvm.10630154938325507013 :? (tick-ad2808fb9d249901+0x14c5d5)
    #29 std::panicking::try :? (tick-ad2808fb9d249901+0x14ab40)
    #30 std::panic::catch_unwind :? (tick-ad2808fb9d249901+0x13da55)
    #31 std::rt::lang_start_internal ??:? (tick-ad2808fb9d249901+0x14dd23)
    #32 main ??:? (tick-ad2808fb9d249901+0x95458)
    #33 __libc_start_main ??:? (libc.so.6+0x21bf6)
    #34 __libc_start_main ??:? (libc.so.6+0x21bf6)

SUMMARY: ThreadSanitizer: data race :? in crossbeam_utils::atomic::atomic_cell::AtomicCell<T>::compare_exchange
==================
test recv_two ... ok
test select ... ok
test stress_default ... ok
test try_recv ... ok

test result: ok. 12 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 4.54s
ThreadSanitizer: reported 4 warnings

error: test failed, to rerun pass '-p crossbeam-channel --test tick'

Found in #591 (https://github.com/crossbeam-rs/crossbeam/runs/1647950214?check_suite_focus=true)

[taiki-e]

Seems this only happens if AtomicCell is not lock-free.

The AtomicCell<Instant> used inside tick is not lock-free on Linux.

crossbeam/crossbeam-channel/src/flavors/tick.rs

Lines 19 to 20 in 99c66ec

	/// The instant at which the next message will be delivered.
	delivery_time: AtomicCell<Instant>,

However, AtomicCell<Instant> is lock-free on macOS, and data race does not reported when running ThreadSanitizer on macOS.

RUSTFLAGS="-Z sanitizer=thread --cfg crossbeam_sanitize" \
cargo test -Z build-std --release --target x86_64-apple-darwin -p crossbeam-channel --test tick -- --test-threads=1

[tomtomjhj]

Non-lock-free AtomicCell uses SeqLock which uses Release/Acquire fence, which tsan doesn't understand.

[taiki-e]

That's true. ...So I think we can close this.

[jeehoonkang]

@tomtomjhj do you happen to have enhanced tsan to support those fences?

[tomtomjhj]

@jeehoonkang I guess you're talking about loom. I'll send a PR to loom later and cc you. BTW it's about a simple implementation of Release/SeqCst fence, the correctness of which is unclear yet.

[cynecx]

BTW it's about a simple implementation of Release/SeqCst fence, the correctness of which is unclear yet.

JFYI: loom did have SeqCst fences support (you can still go back and search for the old implementation), however that part was removed because it was broken iirc.

[tomtomjhj]

@cynecx Loom had SeqCst accesses, but not fences. That implementation is indeed incorrect. However, in some alternative memory model for C/C++ without SeqCst accesses (= all SeqCst operations are fence(SeqCst)) , that implementation seems to be correct. So my plan was to suggest dropping the support for SeqCst accesses (panic on SeqCst accesses) and support fence(SeqCst) instead. I think this is ok because algorithms using SeqCst accesses (probably) can be ported to use SeqCst fences only.