[ruby-core:121941] [Ruby Bug#21315] Finalizers violate the `rb_ractor_confirm_belonging` assertion
Issue #21315 has been reported by byroot (Jean Boussier). ---------------------------------------- Bug #21315: Finalizers violate the `rb_ractor_confirm_belonging` assertion https://bugs.ruby-lang.org/issues/21315 * Author: byroot (Jean Boussier) * Status: Open * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Reproduction (with assertions enabled): ```ruby require "tempfile" Ractor.new do 10.times do Tempfile.new end end.take GC.start ``` ``` <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:375> (File) /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2 ruby 3.5.0dev (2025-05-09T15:51:24Z pull/13291/merge e289a1dc58) +PRISM [x86_64-linux] -- Control frame information ----------------------------------------------- c:0005 p:0007 s:0025 e:000024 METHOD /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387 [FINISH] c:0004 p:0022 s:0020 e:000019 METHOD /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833 [FINISH] c:0003 p:---- s:0012 e:000011 CFUNC :parse_lex_file c:0002 p:0006 s:0007 e:000006 BLOCK /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'block in test_parse_lex_file' /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'parse_lex_file' /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833:in 'initialize' /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387:in 'call' -- Threading information --------------------------------------------------- Total ractor count: 2 Ruby thread count for this ractor: 1 -- C level backtrace information ------------------------------------------- /home/runner/work/ruby/ruby/build/ruby(rb_print_backtrace+0x14) [0x561441aeedbf] ../src/vm_dump.c:843 /home/runner/work/ruby/ruby/build/ruby(rb_vm_bugreport) ../src/vm_dump.c:1175 /home/runner/work/ruby/ruby/build/ruby(bug_report_end+0x0) [0x561441aa3f39] ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(rb_bug_without_die_internal) ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(die+0x0) [0x5614416e237f] ../src/error.c:1115 /home/runner/work/ruby/ruby/build/ruby(rb_bug) ../src/error.c:1117 /home/runner/work/ruby/ruby/build/ruby(rb_ractor_confirm_belonging+0xde) [0x56144188c6be] ../src/ractor_core.h:376 /home/runner/work/ruby/ruby/build/ruby(vm_exec_core+0xef) [0x5614418b23ef] /home/runner/work/ruby/ruby/build/vm.inc:2500 /home/runner/work/ruby/ruby/build/ruby(rb_vm_exec+0x156) [0x5614418a4676] ../src/vm.c:2618 /home/runner/work/ruby/ruby/build/ruby(vm_call0_cc+0x13d) [0x5614418aa1dd] ../src/vm_eval.c:101 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call0+0x4c) [0x5614418b1cc5] ../src/vm_eval.c:61 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call_kw) ../src/vm_eval.c:326 /home/runner/work/ruby/ruby/build/ruby(rb_check_funcall_default_kw) ../src/vm_eval.c:694 /home/runner/work/ruby/ruby/build/ruby(rb_gc_run_obj_finalizer+0x1cf) [0x56144170220f] ../src/gc.c:306 /home/runner/work/ruby/ruby/build/ruby(rb_multi_ractor_p+0x0) [0x56144170246f] ../src/gc/default/default.c:2820 /home/runner/work/ruby/ruby/build/ruby(rb_vm_lock_enter) ../src/vm_sync.h:74 /home/runner/work/ruby/ruby/build/ruby(rb_gc_vm_lock) ../src/gc.c:137 /home/runner/work/ruby/ruby/build/ruby(finalize_list) ../src/gc/default/default.c:2843 /home/runner/work/ruby/ruby/build/ruby(finalize_deferred_heap_pages) ../src/gc/default/default.c:2866 ``` I think it wouldn't be hard to disable that check when running a finalizer, but I don't know if it's the correct thing to do. -- https://bugs.ruby-lang.org/
Issue #21315 has been updated by jhawthorn (John Hawthorn). It does seem like it's a problem that this is a way to have access to an unshareable object from multiple ractors ``` def build_finalizer(object) previous_ractor = Ractor.current proc { puts "finalizing on #{Ractor.current} (was: #{previous_ractor}). Passed object: #{object}" } end r = Ractor.new { 1.times do obj1 = Object.new obj2 = Object.new ObjectSpace.define_finalizer(obj1, build_finalizer(obj2)) end Ractor.yield :ok sleep 1 } r.take GC.start r.take ``` prints ``` finalizing on #<Ractor:#1 running> (was: #<Ractor:#2 ractor_finalizer.rb:6 running>). Passed object: #<Object:0x000000010451cde0> ``` So we've given access to an object to the main Ractor even though it should not be shareable. It seems like finalizers run on an arbitrary thread so this could also be a problem in the other direction (unshareable object from main Ractor used as part of finalizer on another). It seems like we should either: - Run each finalizer in the Ractor that created it (what do we do about terminated ractors?) - Disallow finalizers in non-main-Ractors (seems restrictive) - Only allow shareable procs for finalizers in Ractors (seems difficult for users) ---------------------------------------- Bug #21315: Finalizers violate the `rb_ractor_confirm_belonging` assertion https://bugs.ruby-lang.org/issues/21315#change-113063 * Author: byroot (Jean Boussier) * Status: Open * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Reproduction (with assertions enabled): ```ruby require "tempfile" Ractor.new do 10.times do Tempfile.new end end.take GC.start ``` ``` <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:375> (File) /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2 ruby 3.5.0dev (2025-05-09T15:51:24Z pull/13291/merge e289a1dc58) +PRISM [x86_64-linux] -- Control frame information ----------------------------------------------- c:0005 p:0007 s:0025 e:000024 METHOD /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387 [FINISH] c:0004 p:0022 s:0020 e:000019 METHOD /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833 [FINISH] c:0003 p:---- s:0012 e:000011 CFUNC :parse_lex_file c:0002 p:0006 s:0007 e:000006 BLOCK /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'block in test_parse_lex_file' /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'parse_lex_file' /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833:in 'initialize' /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387:in 'call' -- Threading information --------------------------------------------------- Total ractor count: 2 Ruby thread count for this ractor: 1 -- C level backtrace information ------------------------------------------- /home/runner/work/ruby/ruby/build/ruby(rb_print_backtrace+0x14) [0x561441aeedbf] ../src/vm_dump.c:843 /home/runner/work/ruby/ruby/build/ruby(rb_vm_bugreport) ../src/vm_dump.c:1175 /home/runner/work/ruby/ruby/build/ruby(bug_report_end+0x0) [0x561441aa3f39] ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(rb_bug_without_die_internal) ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(die+0x0) [0x5614416e237f] ../src/error.c:1115 /home/runner/work/ruby/ruby/build/ruby(rb_bug) ../src/error.c:1117 /home/runner/work/ruby/ruby/build/ruby(rb_ractor_confirm_belonging+0xde) [0x56144188c6be] ../src/ractor_core.h:376 /home/runner/work/ruby/ruby/build/ruby(vm_exec_core+0xef) [0x5614418b23ef] /home/runner/work/ruby/ruby/build/vm.inc:2500 /home/runner/work/ruby/ruby/build/ruby(rb_vm_exec+0x156) [0x5614418a4676] ../src/vm.c:2618 /home/runner/work/ruby/ruby/build/ruby(vm_call0_cc+0x13d) [0x5614418aa1dd] ../src/vm_eval.c:101 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call0+0x4c) [0x5614418b1cc5] ../src/vm_eval.c:61 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call_kw) ../src/vm_eval.c:326 /home/runner/work/ruby/ruby/build/ruby(rb_check_funcall_default_kw) ../src/vm_eval.c:694 /home/runner/work/ruby/ruby/build/ruby(rb_gc_run_obj_finalizer+0x1cf) [0x56144170220f] ../src/gc.c:306 /home/runner/work/ruby/ruby/build/ruby(rb_multi_ractor_p+0x0) [0x56144170246f] ../src/gc/default/default.c:2820 /home/runner/work/ruby/ruby/build/ruby(rb_vm_lock_enter) ../src/vm_sync.h:74 /home/runner/work/ruby/ruby/build/ruby(rb_gc_vm_lock) ../src/gc.c:137 /home/runner/work/ruby/ruby/build/ruby(finalize_list) ../src/gc/default/default.c:2843 /home/runner/work/ruby/ruby/build/ruby(finalize_deferred_heap_pages) ../src/gc/default/default.c:2866 ``` I think it wouldn't be hard to disable that check when running a finalizer, but I don't know if it's the correct thing to do. -- https://bugs.ruby-lang.org/
Issue #21315 has been updated by byroot (Jean Boussier).
Run each finalizer in the Ractor that created it (what do we do about terminated ractors?)
That one I think would be doable, we could record the current ractor in with the finalizer. For terminated Ractors I don't think it's a big deal, as long as we do what is necessary so that `Ractor.current` and Ractor local storage still work as expected. ---------------------------------------- Bug #21315: Finalizers violate the `rb_ractor_confirm_belonging` assertion https://bugs.ruby-lang.org/issues/21315#change-113064 * Author: byroot (Jean Boussier) * Status: Open * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Reproduction (with assertions enabled): ```ruby require "tempfile" Ractor.new do 10.times do Tempfile.new end end.take GC.start ``` ``` <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:375> (File) /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2 ruby 3.5.0dev (2025-05-09T15:51:24Z pull/13291/merge e289a1dc58) +PRISM [x86_64-linux] -- Control frame information ----------------------------------------------- c:0005 p:0007 s:0025 e:000024 METHOD /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387 [FINISH] c:0004 p:0022 s:0020 e:000019 METHOD /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833 [FINISH] c:0003 p:---- s:0012 e:000011 CFUNC :parse_lex_file c:0002 p:0006 s:0007 e:000006 BLOCK /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'block in test_parse_lex_file' /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'parse_lex_file' /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833:in 'initialize' /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387:in 'call' -- Threading information --------------------------------------------------- Total ractor count: 2 Ruby thread count for this ractor: 1 -- C level backtrace information ------------------------------------------- /home/runner/work/ruby/ruby/build/ruby(rb_print_backtrace+0x14) [0x561441aeedbf] ../src/vm_dump.c:843 /home/runner/work/ruby/ruby/build/ruby(rb_vm_bugreport) ../src/vm_dump.c:1175 /home/runner/work/ruby/ruby/build/ruby(bug_report_end+0x0) [0x561441aa3f39] ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(rb_bug_without_die_internal) ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(die+0x0) [0x5614416e237f] ../src/error.c:1115 /home/runner/work/ruby/ruby/build/ruby(rb_bug) ../src/error.c:1117 /home/runner/work/ruby/ruby/build/ruby(rb_ractor_confirm_belonging+0xde) [0x56144188c6be] ../src/ractor_core.h:376 /home/runner/work/ruby/ruby/build/ruby(vm_exec_core+0xef) [0x5614418b23ef] /home/runner/work/ruby/ruby/build/vm.inc:2500 /home/runner/work/ruby/ruby/build/ruby(rb_vm_exec+0x156) [0x5614418a4676] ../src/vm.c:2618 /home/runner/work/ruby/ruby/build/ruby(vm_call0_cc+0x13d) [0x5614418aa1dd] ../src/vm_eval.c:101 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call0+0x4c) [0x5614418b1cc5] ../src/vm_eval.c:61 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call_kw) ../src/vm_eval.c:326 /home/runner/work/ruby/ruby/build/ruby(rb_check_funcall_default_kw) ../src/vm_eval.c:694 /home/runner/work/ruby/ruby/build/ruby(rb_gc_run_obj_finalizer+0x1cf) [0x56144170220f] ../src/gc.c:306 /home/runner/work/ruby/ruby/build/ruby(rb_multi_ractor_p+0x0) [0x56144170246f] ../src/gc/default/default.c:2820 /home/runner/work/ruby/ruby/build/ruby(rb_vm_lock_enter) ../src/vm_sync.h:74 /home/runner/work/ruby/ruby/build/ruby(rb_gc_vm_lock) ../src/gc.c:137 /home/runner/work/ruby/ruby/build/ruby(finalize_list) ../src/gc/default/default.c:2843 /home/runner/work/ruby/ruby/build/ruby(finalize_deferred_heap_pages) ../src/gc/default/default.c:2866 ``` I think it wouldn't be hard to disable that check when running a finalizer, but I don't know if it's the correct thing to do. -- https://bugs.ruby-lang.org/
Issue #21315 has been updated by Eregon (Benoit Daloze). When a Ractor terminates just before it actually does so it should probably run the remaining finalizers, AFAIK, this is what CRuby does when the process is about to terminate and there are finalizers not run yet (but I might be wrong, though it clearly seems to exhibit that behavior). 3 is a no-no, it's already quite difficult to write correct finalizers (which don't capture the object to finalize), it's basically impossible to write them as shareable procs. ---------------------------------------- Bug #21315: Finalizers violate the `rb_ractor_confirm_belonging` assertion https://bugs.ruby-lang.org/issues/21315#change-113065 * Author: byroot (Jean Boussier) * Status: Open * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Reproduction (with assertions enabled): ```ruby require "tempfile" Ractor.new do 10.times do Tempfile.new end end.take GC.start ``` ``` <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:375> (File) /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2 ruby 3.5.0dev (2025-05-09T15:51:24Z pull/13291/merge e289a1dc58) +PRISM [x86_64-linux] -- Control frame information ----------------------------------------------- c:0005 p:0007 s:0025 e:000024 METHOD /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387 [FINISH] c:0004 p:0022 s:0020 e:000019 METHOD /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833 [FINISH] c:0003 p:---- s:0012 e:000011 CFUNC :parse_lex_file c:0002 p:0006 s:0007 e:000006 BLOCK /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'block in test_parse_lex_file' /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'parse_lex_file' /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833:in 'initialize' /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387:in 'call' -- Threading information --------------------------------------------------- Total ractor count: 2 Ruby thread count for this ractor: 1 -- C level backtrace information ------------------------------------------- /home/runner/work/ruby/ruby/build/ruby(rb_print_backtrace+0x14) [0x561441aeedbf] ../src/vm_dump.c:843 /home/runner/work/ruby/ruby/build/ruby(rb_vm_bugreport) ../src/vm_dump.c:1175 /home/runner/work/ruby/ruby/build/ruby(bug_report_end+0x0) [0x561441aa3f39] ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(rb_bug_without_die_internal) ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(die+0x0) [0x5614416e237f] ../src/error.c:1115 /home/runner/work/ruby/ruby/build/ruby(rb_bug) ../src/error.c:1117 /home/runner/work/ruby/ruby/build/ruby(rb_ractor_confirm_belonging+0xde) [0x56144188c6be] ../src/ractor_core.h:376 /home/runner/work/ruby/ruby/build/ruby(vm_exec_core+0xef) [0x5614418b23ef] /home/runner/work/ruby/ruby/build/vm.inc:2500 /home/runner/work/ruby/ruby/build/ruby(rb_vm_exec+0x156) [0x5614418a4676] ../src/vm.c:2618 /home/runner/work/ruby/ruby/build/ruby(vm_call0_cc+0x13d) [0x5614418aa1dd] ../src/vm_eval.c:101 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call0+0x4c) [0x5614418b1cc5] ../src/vm_eval.c:61 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call_kw) ../src/vm_eval.c:326 /home/runner/work/ruby/ruby/build/ruby(rb_check_funcall_default_kw) ../src/vm_eval.c:694 /home/runner/work/ruby/ruby/build/ruby(rb_gc_run_obj_finalizer+0x1cf) [0x56144170220f] ../src/gc.c:306 /home/runner/work/ruby/ruby/build/ruby(rb_multi_ractor_p+0x0) [0x56144170246f] ../src/gc/default/default.c:2820 /home/runner/work/ruby/ruby/build/ruby(rb_vm_lock_enter) ../src/vm_sync.h:74 /home/runner/work/ruby/ruby/build/ruby(rb_gc_vm_lock) ../src/gc.c:137 /home/runner/work/ruby/ruby/build/ruby(finalize_list) ../src/gc/default/default.c:2843 /home/runner/work/ruby/ruby/build/ruby(finalize_deferred_heap_pages) ../src/gc/default/default.c:2866 ``` I think it wouldn't be hard to disable that check when running a finalizer, but I don't know if it's the correct thing to do. -- https://bugs.ruby-lang.org/
Issue #21315 has been updated by jhawthorn (John Hawthorn).
When a Ractor terminates just before it actually does so it should probably run the remaining finalizers
Objects aren't necessarily unreferenced/garbage collectable at this point (they could have been made shareable, or be the return value taken by a another Ractor). I guess we could do this, but it does seem extremely surprising behaviour to run a finalizer on an accessible live object.
For terminated Ractors I don't think it's a big deal, as long as we do what is necessary so that Ractor.current and Ractor local storage still work as expected.
The final return value of a Ractor is not made shareable, so the `take`-ing Ractor may have access with whatever objects were captured in the finalizer proc. I think we probably need to track that and forward the finalizer to the "next" Ractor (possibly following that several levels until we find a still-running Ractor). ---------------------------------------- Bug #21315: Finalizers violate the `rb_ractor_confirm_belonging` assertion https://bugs.ruby-lang.org/issues/21315#change-113066 * Author: byroot (Jean Boussier) * Status: Open * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Reproduction (with assertions enabled): ```ruby require "tempfile" Ractor.new do 10.times do Tempfile.new end end.take GC.start ``` ``` <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:375> (File) /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2 ruby 3.5.0dev (2025-05-09T15:51:24Z pull/13291/merge e289a1dc58) +PRISM [x86_64-linux] -- Control frame information ----------------------------------------------- c:0005 p:0007 s:0025 e:000024 METHOD /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387 [FINISH] c:0004 p:0022 s:0020 e:000019 METHOD /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833 [FINISH] c:0003 p:---- s:0012 e:000011 CFUNC :parse_lex_file c:0002 p:0006 s:0007 e:000006 BLOCK /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'block in test_parse_lex_file' /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'parse_lex_file' /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833:in 'initialize' /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387:in 'call' -- Threading information --------------------------------------------------- Total ractor count: 2 Ruby thread count for this ractor: 1 -- C level backtrace information ------------------------------------------- /home/runner/work/ruby/ruby/build/ruby(rb_print_backtrace+0x14) [0x561441aeedbf] ../src/vm_dump.c:843 /home/runner/work/ruby/ruby/build/ruby(rb_vm_bugreport) ../src/vm_dump.c:1175 /home/runner/work/ruby/ruby/build/ruby(bug_report_end+0x0) [0x561441aa3f39] ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(rb_bug_without_die_internal) ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(die+0x0) [0x5614416e237f] ../src/error.c:1115 /home/runner/work/ruby/ruby/build/ruby(rb_bug) ../src/error.c:1117 /home/runner/work/ruby/ruby/build/ruby(rb_ractor_confirm_belonging+0xde) [0x56144188c6be] ../src/ractor_core.h:376 /home/runner/work/ruby/ruby/build/ruby(vm_exec_core+0xef) [0x5614418b23ef] /home/runner/work/ruby/ruby/build/vm.inc:2500 /home/runner/work/ruby/ruby/build/ruby(rb_vm_exec+0x156) [0x5614418a4676] ../src/vm.c:2618 /home/runner/work/ruby/ruby/build/ruby(vm_call0_cc+0x13d) [0x5614418aa1dd] ../src/vm_eval.c:101 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call0+0x4c) [0x5614418b1cc5] ../src/vm_eval.c:61 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call_kw) ../src/vm_eval.c:326 /home/runner/work/ruby/ruby/build/ruby(rb_check_funcall_default_kw) ../src/vm_eval.c:694 /home/runner/work/ruby/ruby/build/ruby(rb_gc_run_obj_finalizer+0x1cf) [0x56144170220f] ../src/gc.c:306 /home/runner/work/ruby/ruby/build/ruby(rb_multi_ractor_p+0x0) [0x56144170246f] ../src/gc/default/default.c:2820 /home/runner/work/ruby/ruby/build/ruby(rb_vm_lock_enter) ../src/vm_sync.h:74 /home/runner/work/ruby/ruby/build/ruby(rb_gc_vm_lock) ../src/gc.c:137 /home/runner/work/ruby/ruby/build/ruby(finalize_list) ../src/gc/default/default.c:2843 /home/runner/work/ruby/ruby/build/ruby(finalize_deferred_heap_pages) ../src/gc/default/default.c:2866 ``` I think it wouldn't be hard to disable that check when running a finalizer, but I don't know if it's the correct thing to do. -- https://bugs.ruby-lang.org/
Issue #21315 has been updated by Eregon (Benoit Daloze). Eregon (Benoit Daloze) wrote in #note-3:
it clearly seems to exhibit that behavior
To clarify what I mean: ``` $ ruby -e 'OBJ = Object.new; ObjectSpace.define_finalizer(OBJ) { puts "finalizer ran" }' finalizer ran ``` But clearly that object is always reachable, so the finalizer is run on a live object in this case. We can even print the object in its finalizer: ``` $ ruby -e 'OBJ = Object.new; ObjectSpace.define_finalizer(OBJ) { p OBJ }' #<Object:0x00007f48f9d970a8> ```
it does seem extremely surprising behaviour to run a finalizer on an accessible live object.
I agree, I haven't yet fully understood how this works in CRuby. We tried to replicate the behavior in TruffleRuby but it leds to issues because some objects might depend on other objects for finalization, or rely on finalizers of objects they reference to not run before, and so the order can matter and potentially cause segfaults if run in the wrong order. ---------------------------------------- Bug #21315: Finalizers violate the `rb_ractor_confirm_belonging` assertion https://bugs.ruby-lang.org/issues/21315#change-113067 * Author: byroot (Jean Boussier) * Status: Open * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Reproduction (with assertions enabled): ```ruby require "tempfile" Ractor.new do 10.times do Tempfile.new end end.take GC.start ``` ``` <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:375> (File) /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2 ruby 3.5.0dev (2025-05-09T15:51:24Z pull/13291/merge e289a1dc58) +PRISM [x86_64-linux] -- Control frame information ----------------------------------------------- c:0005 p:0007 s:0025 e:000024 METHOD /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387 [FINISH] c:0004 p:0022 s:0020 e:000019 METHOD /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833 [FINISH] c:0003 p:---- s:0012 e:000011 CFUNC :parse_lex_file c:0002 p:0006 s:0007 e:000006 BLOCK /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'block in test_parse_lex_file' /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'parse_lex_file' /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833:in 'initialize' /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387:in 'call' -- Threading information --------------------------------------------------- Total ractor count: 2 Ruby thread count for this ractor: 1 -- C level backtrace information ------------------------------------------- /home/runner/work/ruby/ruby/build/ruby(rb_print_backtrace+0x14) [0x561441aeedbf] ../src/vm_dump.c:843 /home/runner/work/ruby/ruby/build/ruby(rb_vm_bugreport) ../src/vm_dump.c:1175 /home/runner/work/ruby/ruby/build/ruby(bug_report_end+0x0) [0x561441aa3f39] ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(rb_bug_without_die_internal) ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(die+0x0) [0x5614416e237f] ../src/error.c:1115 /home/runner/work/ruby/ruby/build/ruby(rb_bug) ../src/error.c:1117 /home/runner/work/ruby/ruby/build/ruby(rb_ractor_confirm_belonging+0xde) [0x56144188c6be] ../src/ractor_core.h:376 /home/runner/work/ruby/ruby/build/ruby(vm_exec_core+0xef) [0x5614418b23ef] /home/runner/work/ruby/ruby/build/vm.inc:2500 /home/runner/work/ruby/ruby/build/ruby(rb_vm_exec+0x156) [0x5614418a4676] ../src/vm.c:2618 /home/runner/work/ruby/ruby/build/ruby(vm_call0_cc+0x13d) [0x5614418aa1dd] ../src/vm_eval.c:101 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call0+0x4c) [0x5614418b1cc5] ../src/vm_eval.c:61 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call_kw) ../src/vm_eval.c:326 /home/runner/work/ruby/ruby/build/ruby(rb_check_funcall_default_kw) ../src/vm_eval.c:694 /home/runner/work/ruby/ruby/build/ruby(rb_gc_run_obj_finalizer+0x1cf) [0x56144170220f] ../src/gc.c:306 /home/runner/work/ruby/ruby/build/ruby(rb_multi_ractor_p+0x0) [0x56144170246f] ../src/gc/default/default.c:2820 /home/runner/work/ruby/ruby/build/ruby(rb_vm_lock_enter) ../src/vm_sync.h:74 /home/runner/work/ruby/ruby/build/ruby(rb_gc_vm_lock) ../src/gc.c:137 /home/runner/work/ruby/ruby/build/ruby(finalize_list) ../src/gc/default/default.c:2843 /home/runner/work/ruby/ruby/build/ruby(finalize_deferred_heap_pages) ../src/gc/default/default.c:2866 ``` I think it wouldn't be hard to disable that check when running a finalizer, but I don't know if it's the correct thing to do. -- https://bugs.ruby-lang.org/
Issue #21315 has been updated by luke-gru (Luke Gruber). I agree with John, I think we need to find the next eligible ractor for finalizers after ractor termination. ---------------------------------------- Bug #21315: Finalizers violate the `rb_ractor_confirm_belonging` assertion https://bugs.ruby-lang.org/issues/21315#change-113258 * Author: byroot (Jean Boussier) * Status: Assigned * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Reproduction (with assertions enabled): ```ruby require "tempfile" Ractor.new do 10.times do Tempfile.new end end.take GC.start ``` ``` <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:375> (File) /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2 ruby 3.5.0dev (2025-05-09T15:51:24Z pull/13291/merge e289a1dc58) +PRISM [x86_64-linux] -- Control frame information ----------------------------------------------- c:0005 p:0007 s:0025 e:000024 METHOD /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387 [FINISH] c:0004 p:0022 s:0020 e:000019 METHOD /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833 [FINISH] c:0003 p:---- s:0012 e:000011 CFUNC :parse_lex_file c:0002 p:0006 s:0007 e:000006 BLOCK /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'block in test_parse_lex_file' /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'parse_lex_file' /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833:in 'initialize' /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387:in 'call' -- Threading information --------------------------------------------------- Total ractor count: 2 Ruby thread count for this ractor: 1 -- C level backtrace information ------------------------------------------- /home/runner/work/ruby/ruby/build/ruby(rb_print_backtrace+0x14) [0x561441aeedbf] ../src/vm_dump.c:843 /home/runner/work/ruby/ruby/build/ruby(rb_vm_bugreport) ../src/vm_dump.c:1175 /home/runner/work/ruby/ruby/build/ruby(bug_report_end+0x0) [0x561441aa3f39] ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(rb_bug_without_die_internal) ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(die+0x0) [0x5614416e237f] ../src/error.c:1115 /home/runner/work/ruby/ruby/build/ruby(rb_bug) ../src/error.c:1117 /home/runner/work/ruby/ruby/build/ruby(rb_ractor_confirm_belonging+0xde) [0x56144188c6be] ../src/ractor_core.h:376 /home/runner/work/ruby/ruby/build/ruby(vm_exec_core+0xef) [0x5614418b23ef] /home/runner/work/ruby/ruby/build/vm.inc:2500 /home/runner/work/ruby/ruby/build/ruby(rb_vm_exec+0x156) [0x5614418a4676] ../src/vm.c:2618 /home/runner/work/ruby/ruby/build/ruby(vm_call0_cc+0x13d) [0x5614418aa1dd] ../src/vm_eval.c:101 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call0+0x4c) [0x5614418b1cc5] ../src/vm_eval.c:61 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call_kw) ../src/vm_eval.c:326 /home/runner/work/ruby/ruby/build/ruby(rb_check_funcall_default_kw) ../src/vm_eval.c:694 /home/runner/work/ruby/ruby/build/ruby(rb_gc_run_obj_finalizer+0x1cf) [0x56144170220f] ../src/gc.c:306 /home/runner/work/ruby/ruby/build/ruby(rb_multi_ractor_p+0x0) [0x56144170246f] ../src/gc/default/default.c:2820 /home/runner/work/ruby/ruby/build/ruby(rb_vm_lock_enter) ../src/vm_sync.h:74 /home/runner/work/ruby/ruby/build/ruby(rb_gc_vm_lock) ../src/gc.c:137 /home/runner/work/ruby/ruby/build/ruby(finalize_list) ../src/gc/default/default.c:2843 /home/runner/work/ruby/ruby/build/ruby(finalize_deferred_heap_pages) ../src/gc/default/default.c:2866 ``` I think it wouldn't be hard to disable that check when running a finalizer, but I don't know if it's the correct thing to do. -- https://bugs.ruby-lang.org/
Issue #21315 has been updated by ko1 (Koichi Sasada). it will be fixed with ractor-local GC patch. ---------------------------------------- Bug #21315: Finalizers violate the `rb_ractor_confirm_belonging` assertion https://bugs.ruby-lang.org/issues/21315#change-113281 * Author: byroot (Jean Boussier) * Status: Assigned * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Reproduction (with assertions enabled): ```ruby require "tempfile" Ractor.new do 10.times do Tempfile.new end end.take GC.start ``` ``` <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:375> (File) /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2 ruby 3.5.0dev (2025-05-09T15:51:24Z pull/13291/merge e289a1dc58) +PRISM [x86_64-linux] -- Control frame information ----------------------------------------------- c:0005 p:0007 s:0025 e:000024 METHOD /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387 [FINISH] c:0004 p:0022 s:0020 e:000019 METHOD /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833 [FINISH] c:0003 p:---- s:0012 e:000011 CFUNC :parse_lex_file c:0002 p:0006 s:0007 e:000006 BLOCK /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'block in test_parse_lex_file' /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'parse_lex_file' /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833:in 'initialize' /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387:in 'call' -- Threading information --------------------------------------------------- Total ractor count: 2 Ruby thread count for this ractor: 1 -- C level backtrace information ------------------------------------------- /home/runner/work/ruby/ruby/build/ruby(rb_print_backtrace+0x14) [0x561441aeedbf] ../src/vm_dump.c:843 /home/runner/work/ruby/ruby/build/ruby(rb_vm_bugreport) ../src/vm_dump.c:1175 /home/runner/work/ruby/ruby/build/ruby(bug_report_end+0x0) [0x561441aa3f39] ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(rb_bug_without_die_internal) ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(die+0x0) [0x5614416e237f] ../src/error.c:1115 /home/runner/work/ruby/ruby/build/ruby(rb_bug) ../src/error.c:1117 /home/runner/work/ruby/ruby/build/ruby(rb_ractor_confirm_belonging+0xde) [0x56144188c6be] ../src/ractor_core.h:376 /home/runner/work/ruby/ruby/build/ruby(vm_exec_core+0xef) [0x5614418b23ef] /home/runner/work/ruby/ruby/build/vm.inc:2500 /home/runner/work/ruby/ruby/build/ruby(rb_vm_exec+0x156) [0x5614418a4676] ../src/vm.c:2618 /home/runner/work/ruby/ruby/build/ruby(vm_call0_cc+0x13d) [0x5614418aa1dd] ../src/vm_eval.c:101 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call0+0x4c) [0x5614418b1cc5] ../src/vm_eval.c:61 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call_kw) ../src/vm_eval.c:326 /home/runner/work/ruby/ruby/build/ruby(rb_check_funcall_default_kw) ../src/vm_eval.c:694 /home/runner/work/ruby/ruby/build/ruby(rb_gc_run_obj_finalizer+0x1cf) [0x56144170220f] ../src/gc.c:306 /home/runner/work/ruby/ruby/build/ruby(rb_multi_ractor_p+0x0) [0x56144170246f] ../src/gc/default/default.c:2820 /home/runner/work/ruby/ruby/build/ruby(rb_vm_lock_enter) ../src/vm_sync.h:74 /home/runner/work/ruby/ruby/build/ruby(rb_gc_vm_lock) ../src/gc.c:137 /home/runner/work/ruby/ruby/build/ruby(finalize_list) ../src/gc/default/default.c:2843 /home/runner/work/ruby/ruby/build/ruby(finalize_deferred_heap_pages) ../src/gc/default/default.c:2866 ``` I think it wouldn't be hard to disable that check when running a finalizer, but I don't know if it's the correct thing to do. -- https://bugs.ruby-lang.org/
Issue #21315 has been updated by ko1 (Koichi Sasada). Status changed from Assigned to Closed Re-checked on master 4d185cce78 with a RUBY_DEBUG=1 build (RACTOR_CHECK_MODE > 0). Both halves of this ticket are fixed by the per-Ractor GC work (GH-18194), as I expected in #note-8. 1. The assertion in the description no longer fires: require "tempfile" Ractor.new { 10.times { Tempfile.new } }.join GC.start # master, RUBY_DEBUG=1: no assertion failure 2. jhawthorn's case in #note-1 -- a finalizer defined inside a Ractor running in the main Ractor and handing it an unshareable object -- is gone. That script now prints: ruby 4.0.2 : finalizing on #<Ractor:#1 running> (was: #<Ractor:#2 ...>) master : finalizing on #<Ractor:#2 running> (was: #<Ractor:#2 ...>) The finalizer runs in the Ractor that defined it, so the object it captured is never reachable from two Ractors at the same time. On the "what about terminated Ractors?" question from the thread: once a Ractor has terminated and its objspace has been absorbed by the joining Ractor, its outstanding finalizers run there. That is consistent, because at that point nothing else can reach those objects. ---------------------------------------- Bug #21315: Finalizers violate the `rb_ractor_confirm_belonging` assertion https://bugs.ruby-lang.org/issues/21315#change-118832 * Author: byroot (Jean Boussier) * Status: Closed * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Reproduction (with assertions enabled): ```ruby require "tempfile" Ractor.new do 10.times do Tempfile.new end end.take GC.start ``` ``` <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:375> (File) /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2 ruby 3.5.0dev (2025-05-09T15:51:24Z pull/13291/merge e289a1dc58) +PRISM [x86_64-linux] -- Control frame information ----------------------------------------------- c:0005 p:0007 s:0025 e:000024 METHOD /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387 [FINISH] c:0004 p:0022 s:0020 e:000019 METHOD /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833 [FINISH] c:0003 p:---- s:0012 e:000011 CFUNC :parse_lex_file c:0002 p:0006 s:0007 e:000006 BLOCK /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'block in test_parse_lex_file' /home/runner/work/ruby/ruby/src/test/prism/ractor_test.rb:26:in 'parse_lex_file' /home/runner/work/ruby/ruby/src/lib/prism/parse_result.rb:833:in 'initialize' /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387:in 'call' -- Threading information --------------------------------------------------- Total ractor count: 2 Ruby thread count for this ractor: 1 -- C level backtrace information ------------------------------------------- /home/runner/work/ruby/ruby/build/ruby(rb_print_backtrace+0x14) [0x561441aeedbf] ../src/vm_dump.c:843 /home/runner/work/ruby/ruby/build/ruby(rb_vm_bugreport) ../src/vm_dump.c:1175 /home/runner/work/ruby/ruby/build/ruby(bug_report_end+0x0) [0x561441aa3f39] ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(rb_bug_without_die_internal) ../src/error.c:1097 /home/runner/work/ruby/ruby/build/ruby(die+0x0) [0x5614416e237f] ../src/error.c:1115 /home/runner/work/ruby/ruby/build/ruby(rb_bug) ../src/error.c:1117 /home/runner/work/ruby/ruby/build/ruby(rb_ractor_confirm_belonging+0xde) [0x56144188c6be] ../src/ractor_core.h:376 /home/runner/work/ruby/ruby/build/ruby(vm_exec_core+0xef) [0x5614418b23ef] /home/runner/work/ruby/ruby/build/vm.inc:2500 /home/runner/work/ruby/ruby/build/ruby(rb_vm_exec+0x156) [0x5614418a4676] ../src/vm.c:2618 /home/runner/work/ruby/ruby/build/ruby(vm_call0_cc+0x13d) [0x5614418aa1dd] ../src/vm_eval.c:101 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call0+0x4c) [0x5614418b1cc5] ../src/vm_eval.c:61 /home/runner/work/ruby/ruby/build/ruby(rb_vm_call_kw) ../src/vm_eval.c:326 /home/runner/work/ruby/ruby/build/ruby(rb_check_funcall_default_kw) ../src/vm_eval.c:694 /home/runner/work/ruby/ruby/build/ruby(rb_gc_run_obj_finalizer+0x1cf) [0x56144170220f] ../src/gc.c:306 /home/runner/work/ruby/ruby/build/ruby(rb_multi_ractor_p+0x0) [0x56144170246f] ../src/gc/default/default.c:2820 /home/runner/work/ruby/ruby/build/ruby(rb_vm_lock_enter) ../src/vm_sync.h:74 /home/runner/work/ruby/ruby/build/ruby(rb_gc_vm_lock) ../src/gc.c:137 /home/runner/work/ruby/ruby/build/ruby(finalize_list) ../src/gc/default/default.c:2843 /home/runner/work/ruby/ruby/build/ruby(finalize_deferred_heap_pages) ../src/gc/default/default.c:2866 ``` I think it wouldn't be hard to disable that check when running a finalizer, but I don't know if it's the correct thing to do. -- https://bugs.ruby-lang.org/
participants (5)
-
byroot (Jean Boussier) -
Eregon (Benoit Daloze)
-
jhawthorn (John Hawthorn)
-
ko1 (Koichi Sasada)
-
luke-gru (Luke Gruber)