Unable to interrupt execution by using SIGINT

[JohnReppy]

Version

110.99.2

Operating System

• All
• Linux
• macOS
• Windows
• Other Unix

OS Version

No response

Processor

No response

Component

Core system

Severity

Major

Description of the problem

In smlnj v110.99.2, I am not able to interrupt the execution of an expression by sending SIGINT to smlnj.
For example, if I run an infinite loop while true do ();, I am not able to stop it by pressing CTRL-C.
Older versions of smlnj do not seem to have this problem. In smlnj v110.79, I am able to stop the infinite loop using CTRL-C:

Standard ML of New Jersey v110.79 [built: Sun Oct 27 08:29:41 2019]

• while true do ();

Interrupt

Transcript

No response

Expected Behavior

No response

Steps to Reproduce

No response

Additional Information

No response

Email address

No response

Comments from smlnj-gforge

Original smlnj-gforge bug number 311

Submitted on 2022-05-19 at 23:50:00

comment by @JohnReppy on 2022-05-20 09:20:00 +000 UTC

I was unable to reproduce this bug (macOS/arm64) Since the report does not provide any contact info and does not specify the version of Unix/architecture, I'm not able to do further testing or ask for additional information.

[JohnReppy]

I have also verified that this issue is not a problem on Linux in the 110.99.3.

[JohnReppy]

Based on email from the original submitter, the problem is actually with the way that the signal-handling state is being maintained across exportML. If a signal is set to be ignored in the environment when exportML is called, that behavior is preserved when the program is restarted. We need to figure out a precise description of signal semantics (and how it interacts with exportML and exportFn) and correct the implementation.

[JohnReppy]

Fixed this problem by delaying the setup of the signal handler state until after the heap image is loaded. This change means that the signals that are ignored when the image is created, but not when the image is run, will not be ignored.