timer-thread may set trap interrupt with rb_threadptr_check_signal
at any time independent of GVL. This means timer-thread may set
the trap interrupt flag on the previous execution context; causing
the flag to be unnoticed until a future ec switch (or lost
completely if the ec is done).
Note: I avoid relying on th->interrupt_lock here and use
atomics because we won't be able to rely on it for proposed lazy
timer-thread [Misc #14937].
This regression affects Ruby 2.5 as it was introduced by moving
interrupt_flag to `ec' which is an unstable pointer. Ruby <= 2.4
was unaffected because vm->main_thread->interrupt_flag never
changed.
cont.c (ec_switch): prevent delayed/missed trap interrupt race
timer-thread may set trap interrupt with rb_threadptr_check_signal
at any time independent of GVL. This means timer-thread may set
the trap interrupt flag on the previous execution context; causing
the flag to be unnoticed until a future ec switch (or lost
completely if the ec is done).
Note: I avoid relying on th->interrupt_lock here and use
atomics because we won't be able to rely on it for proposed lazy
timer-thread [Misc #14937].
This regression affects Ruby 2.5 as it was introduced by moving
interrupt_flag to `ec' which is an unstable pointer. Ruby <= 2.4
was unaffected because vm->main_thread->interrupt_flag never
changed.
[ruby-core:88119] [Bug #14939]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64062 b2dd03c8-39d4-4d8f-98ff-823fe69b080e