Use main Ractor EC on threads without EC #4108
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Previously in threads which weren't created to running Ruby (which includes the timer thread), calling rb_postponed_job_register_one as well as probably similar hooks would cause a segfault due to the now-thread-local EC being NULL. This was particularly a problem for profiling tools (like stackprof), which rely on signal handlers, which may be sent to any thread in the process including those not managed by Ruby. [Fixes #17573] Co-authored-by: John Crepezzi <john.crepezzi@gmail.com>
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XrXr
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Nov 23, 2021
After 5680c38, postponed job APIs now expect to be called on native threads not managed by Ruby and handles getting a NULL execution context. However, in debug builds the change runs into an assertion failure with GET_EC() which asserts that EC is non-NULL. Avoid the assertion failure by passing `false` for `expect_ec` instead as the intention is to handle when there is no EC. Add a test from John Crepezzi and John Hawthorn to exercise this situation. See GH-4108 See GH-5094 [Bug #17573] Co-authored-by: John Hawthorn <john@hawthorn.email> Co-authored-by: John Crepezzi <john.crepezzi@gmail.com>
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…Backport #17573] Use valid `ec` for postponed job. Postponed job can be registered from non-Ruby thread, which means `ec` in TLS can be NULL. In this case, use main thread's `ec` instead. See #4108 and #4336 --- vm_trace.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) Avoid assert failure when NULL EC is expected After 5680c38, postponed job APIs now expect to be called on native threads not managed by Ruby and handles getting a NULL execution context. However, in debug builds the change runs into an assertion failure with GET_EC() which asserts that EC is non-NULL. Avoid the assertion failure by passing `false` for `expect_ec` instead as the intention is to handle when there is no EC. Add a test from John Crepezzi and John Hawthorn to exercise this situation. See GH-4108 See GH-5094 [Bug #17573] Co-authored-by: John Hawthorn <john@hawthorn.email> Co-authored-by: John Crepezzi <john.crepezzi@gmail.com> --- ext/-test-/postponed_job/postponed_job.c | 31 ++++++++++++++++++++++++++ test/-ext-/postponed_job/test_postponed_job.rb | 7 ++++++ vm_trace.c | 2 +- 3 files changed, 39 insertions(+), 1 deletion(-)
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Previously in threads which weren't created to running Ruby (which includes the timer thread), calling rb_postponed_job_register_one as well as probably similar hooks would cause a segfault due to the now-thread-local EC being NULL.
This was particularly a problem for profiling tools (like stackprof), which rely on signal handlers, which may be sent to any thread in the process including those not managed by Ruby.