[ruby-core:119991] [Ruby master Bug#20905] Ruby VM hangs while using ractors
Issue #20905 has been reported by ivoanjo (Ivo Anjo). ---------------------------------------- Bug #20905: Ruby VM hangs while using ractors https://bugs.ruby-lang.org/issues/20905 * Author: ivoanjo (Ivo Anjo) * Status: Open * ruby -v: ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Hey! While doing some experiments with Ractors I ran into a Ruby VM hang. I see it both on Ruby 3.4.0-preview2 and 3.3.5, but not Ruby 3.2, so this may be related to the M:N scheduling. ### How to reproduce: ``` puts RUBY_DESCRIPTION def counter_loop counter = 0 counter += 1 while counter < 100_000_000 end ractors = 10.times.map { Ractor.new { Thread.new { counter_loop }; counter_loop } } counter_loop ractors.map(&:take) ``` This example never finishes for me. At some point all threads finish work, and the Ruby process will be stuck at 0% cpu. ``` ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues. ...(hangs)... ``` Reducing the number of ractor seems to make the issue go away, so there may be some timing/thread switching issues involved. Furthermore, all threads seem to be stuck waiting: ``` (gdb) info threads Id Target Id Frame * 1 Thread 0x7836ef0b6c00 (LWP 445418) "ruby" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 2 Thread 0x7836d4800640 (LWP 445419) "ruby" 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 3 Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 4 Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 5 Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 6 Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 7 Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 8 Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 9 Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 (gdb) thread apply all bt Thread 9 (Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40251e800) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 8 (Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025224e0) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 7 (Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025adf00) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 6 (Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40263bc20) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 5 (Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40276bc80) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 4 (Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a402729730) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 3 (Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4024bb430) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 2 (Thread 0x7836d4800640 (LWP 445419) "ruby"): #0 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 #1 0x00007836eecdca8d in event_wait (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:2940 #2 timer_thread_polling (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread_mn.c:908 #3 timer_thread_func (ptr=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:3067 #4 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #5 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 1 (Thread 0x7836ef0b6c00 (LWP 445418) "ruby"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024bda30, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024bdb80, cond=0x59a4024bda08) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eecd90d9 in thread_sched_wait_running_turn (sched=sched@entry=0x59a4024bdb80, th=0x59a4024b88c0, can_direct_transfer=can_direct_transfer@entry=false) at src/ruby-3.4.0-preview2/thread_pthread.c:863 #7 0x00007836eecd9f4a in rb_ractor_sched_sleep (ec=ec@entry=0x59a4024bdd20, cr=cr@entry=0x59a4024bda60, ubf=ubf@entry=0x7836eec341f0 <ractor_sleep_interrupt>) at src/ruby-3.4.0-preview2/thread_pthread.c:1349 #8 0x00007836eec34de6 in ractor_sleep_with_cleanup (cf_data=0x7ffcaa1e7640, cf_func=0x7836eec35b70 <ractor_wait_take_cleanup>, wait_status=wait_taking, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:691 #9 ractor_wait_take (take_basket=0x7ffcaa1e7650, r=0x59a4027851d0, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:1220 #10 ractor_take (r=0x59a4027851d0, ec=0x59a4024bdd20) at ractor.c:1241 #11 builtin_inline_class_711 (ec=0x59a4024bdd20, self=<optimised out>) at src/ruby-3.4.0-preview2/ractor.rb:712 #12 0x00007836eed30fe7 in invoke_bf (argv=<optimised out>, bf=<optimised out>, reg_cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7330 #13 vm_invoke_builtin_delegate (cfp=<optimised out>, bf=<optimised out>, cfp=<optimised out>, bf=<optimised out>, start_index=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7353 #14 vm_invoke_builtin_delegate (start_index=<optimised out>, bf=<optimised out>, cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7342 #15 vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:1632 #16 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #17 0x00007836eed3b222 in vm_call0_cc (ec=0x59a4024bdd20, recv=132176890167200, id=<optimised out>, argc=<optimised out>, argv=<optimised out>, cc=<optimised out>, kw_splat=0) at src/ruby-3.4.0-preview2/vm_eval.c:101 #18 0x00007836eed3d9e4 in rb_call0 (ec=0x59a4024bdd20, recv=132176890167200, mid=6081, argc=0, argv=<optimised out>, call_scope=<optimised out>, self=132177315121880) at src/ruby-3.4.0-preview2/vm_eval.c:554 #19 0x00007836eed3e6f6 in rb_call (scope=<optimised out>, argv=0x7ffcaa1e7b40, argc=0, mid=6081, recv=132176890167200) at src/ruby-3.4.0-preview2/vm_eval.c:873 #20 rb_funcall_with_block_kw (recv=132176890167200, mid=6081, argc=0, argv=0x7ffcaa1e7b40, passed_procval=4, kw_splat=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1192 #21 0x00007836eed39e38 in vm_yield_with_cref (is_lambda=0, cref=0x0, kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1646 #22 vm_yield (kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1654 #23 rb_yield_0 (argv=0x7ffcaa1e7b38, argc=1) at src/ruby-3.4.0-preview2/vm_eval.c:1344 #24 rb_yield (val=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1360 #25 0x00007836eea68efc in rb_ary_collect (ary=132177315121880) at array.c:3714 #26 0x00007836eed1b03c in vm_call_cfunc_with_frame_ (stack_bottom=<optimised out>, argv=<optimised out>, argc=0, calling=<optimised out>, reg_cfp=0x7836edffefa0, ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3788 #27 vm_call_cfunc_with_frame (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, calling=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3834 #28 0x00007836eed217f0 in vm_sendish (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, cd=0x59a4027833f0, block_handler=<optimised out>, method_explorer=mexp_search_method) at src/ruby-3.4.0-preview2/vm_callinfo.h:415 #29 0x00007836eed2edd1 in vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:851 #30 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #31 0x00007836eed46e8b in rb_iseq_eval_main (iseq=iseq@entry=0x7836edea70f8) at vm.c:2830 #32 0x00007836eeb3d895 in rb_ec_exec_node (ec=ec@entry=0x59a4024bdd20, n=n@entry=0x7836edea70f8) at eval.c:281 #33 0x00007836eeb4140b in ruby_run_node (n=0x7836edea70f8) at eval.c:319 #34 0x000059a400cd1187 in rb_main (argv=0x7ffcaa1e8118, argc=2) at ./main.c:43 #35 main (argc=<optimised out>, argv=<optimised out>) at ./main.c:62 ``` -- https://bugs.ruby-lang.org/
Issue #20905 has been updated by luke-gru (Luke Gruber). I took a look at this, and it occurs due to an issue in the ractor and thread scheduler. Sometimes a ractor is not enqueued when it should be, therefore all native threads are blocked on `ractor_sched_deq` and they can't continue even if there is more work. I made a PR for this issue here, but I don't know if it is an acceptable fix. I'm fairly certain about it, though. https://github.com/ruby/ruby/pull/12520 ---------------------------------------- Bug #20905: Ruby VM hangs while using ractors https://bugs.ruby-lang.org/issues/20905#change-111303 * Author: ivoanjo (Ivo Anjo) * Status: Open * ruby -v: ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Hey! While doing some experiments with Ractors I ran into a Ruby VM hang. I see it both on Ruby 3.4.0-preview2 and 3.3.5, but not Ruby 3.2, so this may be related to the M:N scheduling. ### How to reproduce: ``` puts RUBY_DESCRIPTION def counter_loop counter = 0 counter += 1 while counter < 100_000_000 end ractors = 10.times.map { Ractor.new { Thread.new { counter_loop }; counter_loop } } counter_loop ractors.map(&:take) ``` This example never finishes for me. At some point all threads finish work, and the Ruby process will be stuck at 0% cpu. ``` ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues. ...(hangs)... ``` Reducing the number of ractor seems to make the issue go away, so there may be some timing/thread switching issues involved. Furthermore, all threads seem to be stuck waiting: ``` (gdb) info threads Id Target Id Frame * 1 Thread 0x7836ef0b6c00 (LWP 445418) "ruby" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 2 Thread 0x7836d4800640 (LWP 445419) "ruby" 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 3 Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 4 Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 5 Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 6 Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 7 Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 8 Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 9 Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 (gdb) thread apply all bt Thread 9 (Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40251e800) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 8 (Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025224e0) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 7 (Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025adf00) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 6 (Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40263bc20) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 5 (Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40276bc80) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 4 (Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a402729730) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 3 (Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4024bb430) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 2 (Thread 0x7836d4800640 (LWP 445419) "ruby"): #0 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 #1 0x00007836eecdca8d in event_wait (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:2940 #2 timer_thread_polling (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread_mn.c:908 #3 timer_thread_func (ptr=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:3067 #4 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #5 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 1 (Thread 0x7836ef0b6c00 (LWP 445418) "ruby"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024bda30, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024bdb80, cond=0x59a4024bda08) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eecd90d9 in thread_sched_wait_running_turn (sched=sched@entry=0x59a4024bdb80, th=0x59a4024b88c0, can_direct_transfer=can_direct_transfer@entry=false) at src/ruby-3.4.0-preview2/thread_pthread.c:863 #7 0x00007836eecd9f4a in rb_ractor_sched_sleep (ec=ec@entry=0x59a4024bdd20, cr=cr@entry=0x59a4024bda60, ubf=ubf@entry=0x7836eec341f0 <ractor_sleep_interrupt>) at src/ruby-3.4.0-preview2/thread_pthread.c:1349 #8 0x00007836eec34de6 in ractor_sleep_with_cleanup (cf_data=0x7ffcaa1e7640, cf_func=0x7836eec35b70 <ractor_wait_take_cleanup>, wait_status=wait_taking, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:691 #9 ractor_wait_take (take_basket=0x7ffcaa1e7650, r=0x59a4027851d0, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:1220 #10 ractor_take (r=0x59a4027851d0, ec=0x59a4024bdd20) at ractor.c:1241 #11 builtin_inline_class_711 (ec=0x59a4024bdd20, self=<optimised out>) at src/ruby-3.4.0-preview2/ractor.rb:712 #12 0x00007836eed30fe7 in invoke_bf (argv=<optimised out>, bf=<optimised out>, reg_cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7330 #13 vm_invoke_builtin_delegate (cfp=<optimised out>, bf=<optimised out>, cfp=<optimised out>, bf=<optimised out>, start_index=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7353 #14 vm_invoke_builtin_delegate (start_index=<optimised out>, bf=<optimised out>, cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7342 #15 vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:1632 #16 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #17 0x00007836eed3b222 in vm_call0_cc (ec=0x59a4024bdd20, recv=132176890167200, id=<optimised out>, argc=<optimised out>, argv=<optimised out>, cc=<optimised out>, kw_splat=0) at src/ruby-3.4.0-preview2/vm_eval.c:101 #18 0x00007836eed3d9e4 in rb_call0 (ec=0x59a4024bdd20, recv=132176890167200, mid=6081, argc=0, argv=<optimised out>, call_scope=<optimised out>, self=132177315121880) at src/ruby-3.4.0-preview2/vm_eval.c:554 #19 0x00007836eed3e6f6 in rb_call (scope=<optimised out>, argv=0x7ffcaa1e7b40, argc=0, mid=6081, recv=132176890167200) at src/ruby-3.4.0-preview2/vm_eval.c:873 #20 rb_funcall_with_block_kw (recv=132176890167200, mid=6081, argc=0, argv=0x7ffcaa1e7b40, passed_procval=4, kw_splat=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1192 #21 0x00007836eed39e38 in vm_yield_with_cref (is_lambda=0, cref=0x0, kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1646 #22 vm_yield (kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1654 #23 rb_yield_0 (argv=0x7ffcaa1e7b38, argc=1) at src/ruby-3.4.0-preview2/vm_eval.c:1344 #24 rb_yield (val=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1360 #25 0x00007836eea68efc in rb_ary_collect (ary=132177315121880) at array.c:3714 #26 0x00007836eed1b03c in vm_call_cfunc_with_frame_ (stack_bottom=<optimised out>, argv=<optimised out>, argc=0, calling=<optimised out>, reg_cfp=0x7836edffefa0, ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3788 #27 vm_call_cfunc_with_frame (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, calling=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3834 #28 0x00007836eed217f0 in vm_sendish (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, cd=0x59a4027833f0, block_handler=<optimised out>, method_explorer=mexp_search_method) at src/ruby-3.4.0-preview2/vm_callinfo.h:415 #29 0x00007836eed2edd1 in vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:851 #30 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #31 0x00007836eed46e8b in rb_iseq_eval_main (iseq=iseq@entry=0x7836edea70f8) at vm.c:2830 #32 0x00007836eeb3d895 in rb_ec_exec_node (ec=ec@entry=0x59a4024bdd20, n=n@entry=0x7836edea70f8) at eval.c:281 #33 0x00007836eeb4140b in ruby_run_node (n=0x7836edea70f8) at eval.c:319 #34 0x000059a400cd1187 in rb_main (argv=0x7ffcaa1e8118, argc=2) at ./main.c:43 #35 main (argc=<optimised out>, argv=<optimised out>) at ./main.c:62 ``` -- https://bugs.ruby-lang.org/
Issue #20905 has been updated by byroot (Jean Boussier). I was able to reproduce the bug, and rebasing @luke-gru 's patch does indeed fix the hang (I reduced 100M to 10M though cause it's very long otherwise). @jhawthorn or @tenderlovemaking could you review the PR? The patch make sense to me, but considering my very limited understanding of the scheduler, it doesn't say much. ---------------------------------------- Bug #20905: Ruby VM hangs while using ractors https://bugs.ruby-lang.org/issues/20905#change-113208 * Author: ivoanjo (Ivo Anjo) * Status: Assigned * Assignee: ractor * ruby -v: ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Hey! While doing some experiments with Ractors I ran into a Ruby VM hang. I see it both on Ruby 3.4.0-preview2 and 3.3.5, but not Ruby 3.2, so this may be related to the M:N scheduling. ### How to reproduce: ``` puts RUBY_DESCRIPTION def counter_loop counter = 0 counter += 1 while counter < 100_000_000 end ractors = 10.times.map { Ractor.new { Thread.new { counter_loop }; counter_loop } } counter_loop ractors.map(&:take) ``` This example never finishes for me. At some point all threads finish work, and the Ruby process will be stuck at 0% cpu. ``` ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues. ...(hangs)... ``` Reducing the number of ractor seems to make the issue go away, so there may be some timing/thread switching issues involved. Furthermore, all threads seem to be stuck waiting: ``` (gdb) info threads Id Target Id Frame * 1 Thread 0x7836ef0b6c00 (LWP 445418) "ruby" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 2 Thread 0x7836d4800640 (LWP 445419) "ruby" 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 3 Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 4 Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 5 Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 6 Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 7 Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 8 Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 9 Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 (gdb) thread apply all bt Thread 9 (Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40251e800) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 8 (Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025224e0) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 7 (Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025adf00) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 6 (Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40263bc20) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 5 (Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40276bc80) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 4 (Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a402729730) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 3 (Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4024bb430) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 2 (Thread 0x7836d4800640 (LWP 445419) "ruby"): #0 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 #1 0x00007836eecdca8d in event_wait (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:2940 #2 timer_thread_polling (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread_mn.c:908 #3 timer_thread_func (ptr=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:3067 #4 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #5 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 1 (Thread 0x7836ef0b6c00 (LWP 445418) "ruby"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024bda30, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024bdb80, cond=0x59a4024bda08) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eecd90d9 in thread_sched_wait_running_turn (sched=sched@entry=0x59a4024bdb80, th=0x59a4024b88c0, can_direct_transfer=can_direct_transfer@entry=false) at src/ruby-3.4.0-preview2/thread_pthread.c:863 #7 0x00007836eecd9f4a in rb_ractor_sched_sleep (ec=ec@entry=0x59a4024bdd20, cr=cr@entry=0x59a4024bda60, ubf=ubf@entry=0x7836eec341f0 <ractor_sleep_interrupt>) at src/ruby-3.4.0-preview2/thread_pthread.c:1349 #8 0x00007836eec34de6 in ractor_sleep_with_cleanup (cf_data=0x7ffcaa1e7640, cf_func=0x7836eec35b70 <ractor_wait_take_cleanup>, wait_status=wait_taking, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:691 #9 ractor_wait_take (take_basket=0x7ffcaa1e7650, r=0x59a4027851d0, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:1220 #10 ractor_take (r=0x59a4027851d0, ec=0x59a4024bdd20) at ractor.c:1241 #11 builtin_inline_class_711 (ec=0x59a4024bdd20, self=<optimised out>) at src/ruby-3.4.0-preview2/ractor.rb:712 #12 0x00007836eed30fe7 in invoke_bf (argv=<optimised out>, bf=<optimised out>, reg_cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7330 #13 vm_invoke_builtin_delegate (cfp=<optimised out>, bf=<optimised out>, cfp=<optimised out>, bf=<optimised out>, start_index=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7353 #14 vm_invoke_builtin_delegate (start_index=<optimised out>, bf=<optimised out>, cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7342 #15 vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:1632 #16 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #17 0x00007836eed3b222 in vm_call0_cc (ec=0x59a4024bdd20, recv=132176890167200, id=<optimised out>, argc=<optimised out>, argv=<optimised out>, cc=<optimised out>, kw_splat=0) at src/ruby-3.4.0-preview2/vm_eval.c:101 #18 0x00007836eed3d9e4 in rb_call0 (ec=0x59a4024bdd20, recv=132176890167200, mid=6081, argc=0, argv=<optimised out>, call_scope=<optimised out>, self=132177315121880) at src/ruby-3.4.0-preview2/vm_eval.c:554 #19 0x00007836eed3e6f6 in rb_call (scope=<optimised out>, argv=0x7ffcaa1e7b40, argc=0, mid=6081, recv=132176890167200) at src/ruby-3.4.0-preview2/vm_eval.c:873 #20 rb_funcall_with_block_kw (recv=132176890167200, mid=6081, argc=0, argv=0x7ffcaa1e7b40, passed_procval=4, kw_splat=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1192 #21 0x00007836eed39e38 in vm_yield_with_cref (is_lambda=0, cref=0x0, kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1646 #22 vm_yield (kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1654 #23 rb_yield_0 (argv=0x7ffcaa1e7b38, argc=1) at src/ruby-3.4.0-preview2/vm_eval.c:1344 #24 rb_yield (val=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1360 #25 0x00007836eea68efc in rb_ary_collect (ary=132177315121880) at array.c:3714 #26 0x00007836eed1b03c in vm_call_cfunc_with_frame_ (stack_bottom=<optimised out>, argv=<optimised out>, argc=0, calling=<optimised out>, reg_cfp=0x7836edffefa0, ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3788 #27 vm_call_cfunc_with_frame (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, calling=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3834 #28 0x00007836eed217f0 in vm_sendish (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, cd=0x59a4027833f0, block_handler=<optimised out>, method_explorer=mexp_search_method) at src/ruby-3.4.0-preview2/vm_callinfo.h:415 #29 0x00007836eed2edd1 in vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:851 #30 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #31 0x00007836eed46e8b in rb_iseq_eval_main (iseq=iseq@entry=0x7836edea70f8) at vm.c:2830 #32 0x00007836eeb3d895 in rb_ec_exec_node (ec=ec@entry=0x59a4024bdd20, n=n@entry=0x7836edea70f8) at eval.c:281 #33 0x00007836eeb4140b in ruby_run_node (n=0x7836edea70f8) at eval.c:319 #34 0x000059a400cd1187 in rb_main (argv=0x7ffcaa1e8118, argc=2) at ./main.c:43 #35 main (argc=<optimised out>, argv=<optimised out>) at ./main.c:62 ``` -- https://bugs.ruby-lang.org/
Issue #20905 has been updated by jhawthorn (John Hawthorn). I had trouble reproducing this, but found that it does reproduce when limiting the number of CPUs. ex. ``` taskset -c 1-3 ruby test.rb ``` ---------------------------------------- Bug #20905: Ruby VM hangs while using ractors https://bugs.ruby-lang.org/issues/20905#change-113401 * Author: ivoanjo (Ivo Anjo) * Status: Assigned * Assignee: ractor * ruby -v: ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Hey! While doing some experiments with Ractors I ran into a Ruby VM hang. I see it both on Ruby 3.4.0-preview2 and 3.3.5, but not Ruby 3.2, so this may be related to the M:N scheduling. ### How to reproduce: ``` puts RUBY_DESCRIPTION def counter_loop counter = 0 counter += 1 while counter < 100_000_000 end ractors = 10.times.map { Ractor.new { Thread.new { counter_loop }; counter_loop } } counter_loop ractors.map(&:take) ``` This example never finishes for me. At some point all threads finish work, and the Ruby process will be stuck at 0% cpu. ``` ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues. ...(hangs)... ``` Reducing the number of ractor seems to make the issue go away, so there may be some timing/thread switching issues involved. Furthermore, all threads seem to be stuck waiting: ``` (gdb) info threads Id Target Id Frame * 1 Thread 0x7836ef0b6c00 (LWP 445418) "ruby" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 2 Thread 0x7836d4800640 (LWP 445419) "ruby" 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 3 Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 4 Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 5 Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 6 Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 7 Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 8 Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 9 Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 (gdb) thread apply all bt Thread 9 (Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40251e800) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 8 (Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025224e0) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 7 (Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025adf00) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 6 (Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40263bc20) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 5 (Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40276bc80) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 4 (Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a402729730) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 3 (Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4024bb430) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 2 (Thread 0x7836d4800640 (LWP 445419) "ruby"): #0 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 #1 0x00007836eecdca8d in event_wait (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:2940 #2 timer_thread_polling (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread_mn.c:908 #3 timer_thread_func (ptr=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:3067 #4 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #5 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 1 (Thread 0x7836ef0b6c00 (LWP 445418) "ruby"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024bda30, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024bdb80, cond=0x59a4024bda08) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eecd90d9 in thread_sched_wait_running_turn (sched=sched@entry=0x59a4024bdb80, th=0x59a4024b88c0, can_direct_transfer=can_direct_transfer@entry=false) at src/ruby-3.4.0-preview2/thread_pthread.c:863 #7 0x00007836eecd9f4a in rb_ractor_sched_sleep (ec=ec@entry=0x59a4024bdd20, cr=cr@entry=0x59a4024bda60, ubf=ubf@entry=0x7836eec341f0 <ractor_sleep_interrupt>) at src/ruby-3.4.0-preview2/thread_pthread.c:1349 #8 0x00007836eec34de6 in ractor_sleep_with_cleanup (cf_data=0x7ffcaa1e7640, cf_func=0x7836eec35b70 <ractor_wait_take_cleanup>, wait_status=wait_taking, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:691 #9 ractor_wait_take (take_basket=0x7ffcaa1e7650, r=0x59a4027851d0, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:1220 #10 ractor_take (r=0x59a4027851d0, ec=0x59a4024bdd20) at ractor.c:1241 #11 builtin_inline_class_711 (ec=0x59a4024bdd20, self=<optimised out>) at src/ruby-3.4.0-preview2/ractor.rb:712 #12 0x00007836eed30fe7 in invoke_bf (argv=<optimised out>, bf=<optimised out>, reg_cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7330 #13 vm_invoke_builtin_delegate (cfp=<optimised out>, bf=<optimised out>, cfp=<optimised out>, bf=<optimised out>, start_index=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7353 #14 vm_invoke_builtin_delegate (start_index=<optimised out>, bf=<optimised out>, cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7342 #15 vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:1632 #16 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #17 0x00007836eed3b222 in vm_call0_cc (ec=0x59a4024bdd20, recv=132176890167200, id=<optimised out>, argc=<optimised out>, argv=<optimised out>, cc=<optimised out>, kw_splat=0) at src/ruby-3.4.0-preview2/vm_eval.c:101 #18 0x00007836eed3d9e4 in rb_call0 (ec=0x59a4024bdd20, recv=132176890167200, mid=6081, argc=0, argv=<optimised out>, call_scope=<optimised out>, self=132177315121880) at src/ruby-3.4.0-preview2/vm_eval.c:554 #19 0x00007836eed3e6f6 in rb_call (scope=<optimised out>, argv=0x7ffcaa1e7b40, argc=0, mid=6081, recv=132176890167200) at src/ruby-3.4.0-preview2/vm_eval.c:873 #20 rb_funcall_with_block_kw (recv=132176890167200, mid=6081, argc=0, argv=0x7ffcaa1e7b40, passed_procval=4, kw_splat=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1192 #21 0x00007836eed39e38 in vm_yield_with_cref (is_lambda=0, cref=0x0, kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1646 #22 vm_yield (kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1654 #23 rb_yield_0 (argv=0x7ffcaa1e7b38, argc=1) at src/ruby-3.4.0-preview2/vm_eval.c:1344 #24 rb_yield (val=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1360 #25 0x00007836eea68efc in rb_ary_collect (ary=132177315121880) at array.c:3714 #26 0x00007836eed1b03c in vm_call_cfunc_with_frame_ (stack_bottom=<optimised out>, argv=<optimised out>, argc=0, calling=<optimised out>, reg_cfp=0x7836edffefa0, ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3788 #27 vm_call_cfunc_with_frame (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, calling=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3834 #28 0x00007836eed217f0 in vm_sendish (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, cd=0x59a4027833f0, block_handler=<optimised out>, method_explorer=mexp_search_method) at src/ruby-3.4.0-preview2/vm_callinfo.h:415 #29 0x00007836eed2edd1 in vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:851 #30 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #31 0x00007836eed46e8b in rb_iseq_eval_main (iseq=iseq@entry=0x7836edea70f8) at vm.c:2830 #32 0x00007836eeb3d895 in rb_ec_exec_node (ec=ec@entry=0x59a4024bdd20, n=n@entry=0x7836edea70f8) at eval.c:281 #33 0x00007836eeb4140b in ruby_run_node (n=0x7836edea70f8) at eval.c:319 #34 0x000059a400cd1187 in rb_main (argv=0x7ffcaa1e8118, argc=2) at ./main.c:43 #35 main (argc=<optimised out>, argv=<optimised out>) at ./main.c:62 ``` -- https://bugs.ruby-lang.org/
Issue #20905 has been updated by jhawthorn (John Hawthorn). Status changed from Assigned to Closed Target version set to 3.5 After @ko1's merge of Ractor::Ports this no longer reproduces. 🎉 @luke-gru and I paired on this both before and after. It seems like what fixed this is removing a check from the end of co_start when a thread terminates (which had a potential race). With that gone it seems like this should be fixed! ---------------------------------------- Bug #20905: Ruby VM hangs while using ractors https://bugs.ruby-lang.org/issues/20905#change-113653 * Author: ivoanjo (Ivo Anjo) * Status: Closed * Assignee: ractor * Target version: 3.5 * ruby -v: ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Hey! While doing some experiments with Ractors I ran into a Ruby VM hang. I see it both on Ruby 3.4.0-preview2 and 3.3.5, but not Ruby 3.2, so this may be related to the M:N scheduling. ### How to reproduce: ``` puts RUBY_DESCRIPTION def counter_loop counter = 0 counter += 1 while counter < 100_000_000 end ractors = 10.times.map { Ractor.new { Thread.new { counter_loop }; counter_loop } } counter_loop ractors.map(&:take) ``` This example never finishes for me. At some point all threads finish work, and the Ruby process will be stuck at 0% cpu. ``` ruby 3.4.0preview2 (2024-10-07 master 32c733f57b) +PRISM [x86_64-linux] warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues. ...(hangs)... ``` Reducing the number of ractor seems to make the issue go away, so there may be some timing/thread switching issues involved. Furthermore, all threads seem to be stuck waiting: ``` (gdb) info threads Id Target Id Frame * 1 Thread 0x7836ef0b6c00 (LWP 445418) "ruby" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 2 Thread 0x7836d4800640 (LWP 445419) "ruby" 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 3 Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 4 Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 5 Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 6 Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 7 Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 8 Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 9 Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 (gdb) thread apply all bt Thread 9 (Thread 0x7836b24fa640 (LWP 445426) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40251e800) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 8 (Thread 0x7836b25fb640 (LWP 445425) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025224e0) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 7 (Thread 0x7836b26fc640 (LWP 445424) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4025adf00) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 6 (Thread 0x7836b27fd640 (LWP 445423) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40263bc20) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 5 (Thread 0x7836b28fe640 (LWP 445422) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6430) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6430, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a40276bc80) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 4 (Thread 0x7836b29ff640 (LWP 445421) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a402729730) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 3 (Thread 0x7836d3fff640 (LWP 445420) "rc-example7-2.*"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024b6434) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024b6434, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024b63d0, cond=0x59a4024b6408) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024b6408, mutex=mutex@entry=0x59a4024b63d0) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eece2e53 in ractor_sched_deq (cr=0x0, vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:1292 #7 nt_start (ptr=0x59a4024bb430) at src/ruby-3.4.0-preview2/thread_pthread.c:2287 #8 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #9 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 2 (Thread 0x7836d4800640 (LWP 445419) "ruby"): #0 0x00007836ee725e2e in epoll_wait (epfd=4, events=events@entry=0x7836ef0a8adc <timer_th+28>, maxevents=maxevents@entry=16, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30 #1 0x00007836eecdca8d in event_wait (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:2940 #2 timer_thread_polling (vm=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread_mn.c:908 #3 timer_thread_func (ptr=0x59a4024b6330) at src/ruby-3.4.0-preview2/thread_pthread.c:3067 #4 0x00007836ee694ac3 in start_thread (arg=<optimised out>) at ./nptl/pthread_create.c:442 #5 0x00007836ee726850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 Thread 1 (Thread 0x7836ef0b6c00 (LWP 445418) "ruby"): #0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:57 #1 __futex_abstimed_wait_common (cancel=true, private=0, abstime=0x0, clockid=0, expected=0, futex_word=0x59a4024bda30) at ./nptl/futex-internal.c:87 #2 __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x59a4024bda30, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139 #3 0x00007836ee693a41 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x59a4024bdb80, cond=0x59a4024bda08) at ./nptl/pthread_cond_wait.c:503 #4 ___pthread_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at ./nptl/pthread_cond_wait.c:627 #5 0x00007836eecd77dd in rb_native_cond_wait (cond=cond@entry=0x59a4024bda08, mutex=mutex@entry=0x59a4024bdb80) at src/ruby-3.4.0-preview2/thread_pthread.c:222 #6 0x00007836eecd90d9 in thread_sched_wait_running_turn (sched=sched@entry=0x59a4024bdb80, th=0x59a4024b88c0, can_direct_transfer=can_direct_transfer@entry=false) at src/ruby-3.4.0-preview2/thread_pthread.c:863 #7 0x00007836eecd9f4a in rb_ractor_sched_sleep (ec=ec@entry=0x59a4024bdd20, cr=cr@entry=0x59a4024bda60, ubf=ubf@entry=0x7836eec341f0 <ractor_sleep_interrupt>) at src/ruby-3.4.0-preview2/thread_pthread.c:1349 #8 0x00007836eec34de6 in ractor_sleep_with_cleanup (cf_data=0x7ffcaa1e7640, cf_func=0x7836eec35b70 <ractor_wait_take_cleanup>, wait_status=wait_taking, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:691 #9 ractor_wait_take (take_basket=0x7ffcaa1e7650, r=0x59a4027851d0, cr=0x59a4024bda60, ec=0x59a4024bdd20) at ractor.c:1220 #10 ractor_take (r=0x59a4027851d0, ec=0x59a4024bdd20) at ractor.c:1241 #11 builtin_inline_class_711 (ec=0x59a4024bdd20, self=<optimised out>) at src/ruby-3.4.0-preview2/ractor.rb:712 #12 0x00007836eed30fe7 in invoke_bf (argv=<optimised out>, bf=<optimised out>, reg_cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7330 #13 vm_invoke_builtin_delegate (cfp=<optimised out>, bf=<optimised out>, cfp=<optimised out>, bf=<optimised out>, start_index=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7353 #14 vm_invoke_builtin_delegate (start_index=<optimised out>, bf=<optimised out>, cfp=<optimised out>, ec=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:7342 #15 vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:1632 #16 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #17 0x00007836eed3b222 in vm_call0_cc (ec=0x59a4024bdd20, recv=132176890167200, id=<optimised out>, argc=<optimised out>, argv=<optimised out>, cc=<optimised out>, kw_splat=0) at src/ruby-3.4.0-preview2/vm_eval.c:101 #18 0x00007836eed3d9e4 in rb_call0 (ec=0x59a4024bdd20, recv=132176890167200, mid=6081, argc=0, argv=<optimised out>, call_scope=<optimised out>, self=132177315121880) at src/ruby-3.4.0-preview2/vm_eval.c:554 #19 0x00007836eed3e6f6 in rb_call (scope=<optimised out>, argv=0x7ffcaa1e7b40, argc=0, mid=6081, recv=132176890167200) at src/ruby-3.4.0-preview2/vm_eval.c:873 #20 rb_funcall_with_block_kw (recv=132176890167200, mid=6081, argc=0, argv=0x7ffcaa1e7b40, passed_procval=4, kw_splat=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1192 #21 0x00007836eed39e38 in vm_yield_with_cref (is_lambda=0, cref=0x0, kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1646 #22 vm_yield (kw_splat=0, argv=0x7ffcaa1e7b38, argc=1, ec=<optimised out>) at vm.c:1654 #23 rb_yield_0 (argv=0x7ffcaa1e7b38, argc=1) at src/ruby-3.4.0-preview2/vm_eval.c:1344 #24 rb_yield (val=<optimised out>) at src/ruby-3.4.0-preview2/vm_eval.c:1360 #25 0x00007836eea68efc in rb_ary_collect (ary=132177315121880) at array.c:3714 #26 0x00007836eed1b03c in vm_call_cfunc_with_frame_ (stack_bottom=<optimised out>, argv=<optimised out>, argc=0, calling=<optimised out>, reg_cfp=0x7836edffefa0, ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3788 #27 vm_call_cfunc_with_frame (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, calling=<optimised out>) at src/ruby-3.4.0-preview2/vm_insnhelper.c:3834 #28 0x00007836eed217f0 in vm_sendish (ec=0x59a4024bdd20, reg_cfp=0x7836edffefa0, cd=0x59a4027833f0, block_handler=<optimised out>, method_explorer=mexp_search_method) at src/ruby-3.4.0-preview2/vm_callinfo.h:415 #29 0x00007836eed2edd1 in vm_exec_core (ec=0x59a4024bdd20) at src/ruby-3.4.0-preview2/insns.def:851 #30 0x00007836eed34c1a in rb_vm_exec (ec=0x59a4024bdd20) at vm.c:2564 #31 0x00007836eed46e8b in rb_iseq_eval_main (iseq=iseq@entry=0x7836edea70f8) at vm.c:2830 #32 0x00007836eeb3d895 in rb_ec_exec_node (ec=ec@entry=0x59a4024bdd20, n=n@entry=0x7836edea70f8) at eval.c:281 #33 0x00007836eeb4140b in ruby_run_node (n=0x7836edea70f8) at eval.c:319 #34 0x000059a400cd1187 in rb_main (argv=0x7ffcaa1e8118, argc=2) at ./main.c:43 #35 main (argc=<optimised out>, argv=<optimised out>) at ./main.c:62 ``` -- https://bugs.ruby-lang.org/
participants (4)
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byroot (Jean Boussier) -
ivoanjo (Ivo Anjo)
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jhawthorn (John Hawthorn)
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luke-gru (Luke Gruber)