Issues

• Proposal: Explore a CAS fast path for Semaphore with native atomics

  ruby-concurrency/concurrent-ruby#1118 · Filter by author Yuhi-Sato opened on Sep 13, 2026

• Deadlock race when calling ScheduledTask#reschedule

  ruby-concurrency/concurrent-ruby#1099 · Filter by author snickell opened on Feb 3, 2026
  9

• Implement FIFO and LRU caches through a Map memory limit

  ruby-concurrency/concurrent-ruby#1095 · Filter by author mrj opened on Dec 8, 2025
  10

• concurrent-ruby rspec testsuite fails with ruby4.0.0dev perhaps due to Set change

  ruby-concurrency/concurrent-ruby#1093 · Filter by author mtasaka opened on Nov 16, 2025
  3

• concurrent_ruby.jar included in gem has no version information included

  ruby-concurrency/concurrent-ruby#1091 · Filter by author dominicgrindle opened on Sep 4, 2025

• ThreadPoolExecutor#kill: documentation and implementation are out of sync

  ruby-concurrency/concurrent-ruby#1072 · Filter by author hms opened on Nov 26, 2024

• Review usages of Integer#size in the gem

  ruby-concurrency/concurrent-ruby#1057 · Filter by author eregon opened on Jul 25, 2024
  4

• should the thread_local_var_accessor gem be included within the concurrent-ruby gem?

  ruby-concurrency/concurrent-ruby#1056 · Filter by author aks opened on Jul 25, 2024
  4

• Add keyword arguments to async

  ruby-concurrency/concurrent-ruby#1040 · Filter by author reeganviljoen opened on Feb 11, 2024
  5

• Add API to prestart threads in threadpools

  ruby-concurrency/concurrent-ruby#1032 · Filter by author catlee opened on Jan 17, 2024
  5

• [REDIRECT] Segfault on Ruby 3.3.0 on linux-aarch64? See https://bugs.ruby-lang.org/issues/20085

  ruby-concurrency/concurrent-ruby#1023 · Filter by author eregon opened on Dec 27, 2023

• DaemonThreadFactory creating new Java thread factory each time it creates a new thread

  ruby-concurrency/concurrent-ruby#1008 · Filter by author obulkin opened on Aug 24, 2023
  8

• why use wait_for_termination method will stuck the code

  ruby-concurrency/concurrent-ruby#1004 · Filter by author banzhihang1 opened on Jul 14, 2023
  2

• CAtomicFixnum should probably be a private constant

  ruby-concurrency/concurrent-ruby#981 · Filter by author eregon opened on Jan 8, 2023
  1

• Concurrent::Hash default initialization is not fully thread-safe

  high-priority
  ruby-concurrency/concurrent-ruby#970 · Filter by author mensfeld opened on Nov 17, 2022
  8

  

• Memory leak in Concurrent::Promises.future

  ruby-concurrency/concurrent-ruby#960 · Filter by author leoarnold opened on Aug 4, 2022
  1

• Memory leak in Concurrent::Future

  ruby-concurrency/concurrent-ruby#959 · Filter by author leoarnold opened on Aug 4, 2022
  2

• Concurrent::Hash and Concurrent::Array are not fully threadsafe on CRuby

  high-priority
  ruby-concurrency/concurrent-ruby#929 · Filter by author jacobat opened on Dec 14, 2021
  9

  

• should we use new c macros included with rubyc?

  enhancementlooking-for-contributor
  ruby-concurrency/concurrent-ruby#897 · Filter by author dsisnero opened on Jan 5, 2021
  1

• Use channel as a stremming object

  ruby-concurrency/concurrent-ruby#895 · Filter by author kvokka opened on Nov 13, 2020

• concurrent-ruby-edge Channel.select consumes full(single core) cpu

  ruby-concurrency/concurrent-ruby#883 · Filter by author adityacs opened on Aug 28, 2020
  1

• Passenger workers hang / segfault with Ruby 2.5 / concurrent-ruby 1.1.6

  bug
  ruby-concurrency/concurrent-ruby#871 · Filter by author astupka opened on May 15, 2020
  3

• Promise.zip hangs on rejected promise in chain

  ruby-concurrency/concurrent-ruby#870 · Filter by author wjordan opened on May 8, 2020

• Bad test behavior when transient test threads die

  ruby-concurrency/concurrent-ruby#862 · Filter by author headius opened on Apr 8, 2020

• Concurrent::Promises::Channel deadlock in example code

  ruby-concurrency/concurrent-ruby#860 · Filter by author ilyacherevkov opened on Mar 19, 2020
  1