[ruby-core:103306] [Ruby master Bug#15735] Thread#handle_interrupt does not prevent Thread#kill from interrupting

[ruby-core:103306] [Ruby master Bug#15735] Thread#handle_interrupt does not prevent Thread#kill from interrupting

[merch-redmine]

Issue #15735 has been updated by jeremyevans0 (Jeremy Evans).


I've determined this is just a documentation issue, and there is a way for `Thread.handle_interrupt` to handle kill/terminate interrupts, which I've committed.

If we handle to allow `Exception` to include these interrupts, we could do something like this:

```diff
--- a/thread.c
+++ b/thread.c
@@ -1992,6 +1992,7 @@ rb_threadptr_pending_interrupt_check_mask(rb_thread_t *th, VALUE err)
     VALUE mod;
     long i;

+  retry:
     for (i=0; i<mask_stack_len; i++) {
        mask = mask_stack[mask_stack_len-(i+1)];

@@ -2023,6 +2024,15 @@ rb_threadptr_pending_interrupt_check_mask(rb_thread_t *th, VALUE err)
        }
        /* try to next mask */
     }
+
+    /* eKillSignal and eTerminateSignal are Integers, but should be
+     * rescued if using Exception in Thread.handle_interrupt.
+     */
+    if (err == rb_cInteger) {
+        err = rb_eException;
+        goto retry;
+    }
+
     return INTERRUPT_NONE;
 }


```

----------------------------------------
Bug #15735: Thread#handle_interrupt does not prevent Thread#kill from interrupting
https://bugs.ruby-lang.org/issues/15735#change-91391

* Author: inoueyu (Yuki INOUE)
* Status: Closed
* Priority: Normal
* ruby -v: 2.6.2p47 (2019-03-13 revision 67232) [x86_64-darwin18]
* Backport: 2.4: UNKNOWN, 2.5: UNKNOWN, 2.6: UNKNOWN
----------------------------------------
https://docs.ruby-lang.org/en/trunk/Thread.html#method-c-handle_interrupt

According to the documentation above, `Thread#handle_interrupt(Exception => :never)` would prevent the interrupts from `Thread#kill`.

In the following code, however, the `Thread#kill` seems to just kill the thread immediately even if the thread is instructed to never handle interrupt.

``` ruby
t = Thread.new do
  Thread.handle_interrupt(Exception => :never) do
    puts "thread started"
    sleep 2
    puts "thread end"
  end
end
sleep 1
t.kill
puts "main end"
sleep 2
```

Outputs

```
$ ruby test.rb
thread started
main end
$ 
```

Is the document wrong?  Or, implementation not working as expected?



-- 
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