Shutdown the runtime only when unforked #4234
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armanbilge
commented
Jan 11, 2025
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| case t => | ||
| runtime.shutdown() | ||
| queue.clear() | ||
| queue.put(t) |
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We don't have access to isForked here. But, I think this particular case doesn't matter, because t is a fatal exception, and point of fatal exceptions in that they may leave the JVM in an inconsistent state (such as stuff not being shutdown/closed). Furthermore it may never have been safe to attempt shutdown here anyway—we don't entirely control this shutdown code, so we couldn't be certain it's not allocating.
| val run: IO[Unit] = | ||
| IO.blocking(System.exit(0)).uncancelable | ||
| val run: IO[Unit] = IO(System.exit(0)) |
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Restores this test to the original state*, now that we fixed this gotcha.
* The original test had uncancelable and I'm not sure why, since I don't think it does anything.
djspiewak
approved these changes
Jan 11, 2025
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It's already explained in the code comment: shutting down the runtime is really only relevant for unforked scenarios.
cats-effect/core/jvm/src/main/scala/cats/effect/IOApp.scala
Lines 505 to 507 in a49a028
By not aggressively shutting down the runtime in the shutdown handler, we fix some gotchas e.g. deadlock if you attempted to execute
System.exiton the runtime.