<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=Windows-1252"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="EN-US" link="blue" vlink="#954F72" style="word-wrap:break-word"> <div class="WordSection1"> Hi Juan,<o:p></o:p> <o:p> </o:p> I hate to bring bad news but I’m afraid there’s still one outstanding issue ;)<o:p></o:p> <o:p> </o:p> s := Semaphore new.<o:p></o:p> [1/0. s signal] fork.<o:p></o:p> s wait.<o:p></o:p> Transcript cr; show: 'done'<o:p></o:p> <o:p> </o:p> If you terminate a blocked UI it means it won’t be able to continue when signaled and won’t print ‘done’ in this case.<o:p></o:p> <o:p> </o:p> This feels like a natural requirement for the blocked UI to continue because if it was just a regular non-UI process we would want it continue too, I guess; like this:<o:p></o:p> <o:p> </o:p> [s := Semaphore new.<o:p></o:p> [1/0. s signal] fork.<o:p></o:p> s wait.<o:p></o:p> Transcript cr; show: 'done'] fork<o:p></o:p> <o:p> </o:p> I look forward to hearing from you again, many thanks!<o:p></o:p> <o:p> </o:p> PS: I tried resuming instead of terminating the oldUIProcess but that of course ends up infamously with two UI processes ;)<o:p></o:p> <o:p> </o:p> Best,<o:p></o:p> Jaromir<o:p></o:p> -- Jaromír Matas<o:p></o:p> mail@jaromir.net <o:p> </o:p> <div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"> From: <a href="mailto:JuanVuletich@zoho.com">Juan Vuletich</a> Sent: Saturday, July 2, 2022 21:55 To: <a href="mailto:cuis-dev@lists.cuis.st">Discussion of Cuis Smalltalk</a> Cc: <a href="mailto:JuanVuletich@zoho.com">Juan Vuletich</a>; <a href="mailto:mail@jaromir.net"> Jaromir Matas</a> Subject: Re: [Cuis-dev] Freezing UI - can't interrupt via Alt+.<o:p></o:p> </div> <o:p> </o:p> Hi Jaromir, I think it is fair to say that if the debugger needs to open, there must be a runnable UI process. Just pushed #5347 for that. I just think that nobody in the Cuis / Squeak community thought about that before. Thanks!!! Cheers, On 7/2/2022 6:03 AM, Jaromir Matas via Cuis-dev wrote: <o:p></o:p> <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"> Hi Juan,<o:p></o:p> <o:p></o:p> the update indeed works, thanks! <o:p> </o:p> An observation though: if you do:<o:p></o:p> 1) Semaphore new wait<o:p></o:p> 2) Alt+.<o:p></o:p> 3) Proceed<o:p></o:p> It disrupts the screen and 'restore display' from the World menu is needed; nothing serious, just reporting because I don't know whether this is to be expected or not :)<o:p></o:p> <o:p></o:p> There's one issue I'd very much like to discuss:<o:p></o:p> <o:p></o:p> s := Semaphore new.<o:p></o:p> [1/0. s signal] fork.<o:p></o:p> s wait<o:p></o:p> <o:p></o:p> When I first ran this example I kind of hoped the UI would not freeze and would open a debugger on the ZeroDivide. I can't see any reason why not behave like that but both Squeak and Cuis freeze because the UI waits on the semaphore and the forked process requests the UI to open a debugger but the UI is stuck at the semaphore :)<o:p></o:p> <o:p></o:p> My expectation was the system would spawn a new UI that would open the debugger but I have no experience with UIs and debuggers and can imagine it may be very tricky :)<o:p></o:p> <o:p></o:p> I'd be very interested in your opinion how the above example could/should be handled by the UI.<o:p></o:p> <o:p></o:p> Of course if you run the example in a non-UI process it works as expected but it'd be nice I guess if running it in the UI would behave similarly :)<o:p></o:p> <o:p></o:p> [s := Semaphore new.<o:p></o:p> [1/0. s signal] fork.<o:p></o:p> s wait] fork<o:p></o:p> <o:p></o:p> Many thanks!<o:p></o:p> Jaromir<o:p></o:p> <o:p></o:p> --<o:p></o:p> Jaromír Matas<o:p></o:p> <a href="mailto:mail@jaromir.net">mail@jaromir.net</a><o:p></o:p> <o:p></o:p> <div style="border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0in 0in 0in;border-color:rgb(225, 225, 225) -moz-use-text-color -moz-use-text-color"> From: <a href="mailto:JuanVuletich@zoho.com">Juan Vuletich</a> Sent: Saturday, July 2, 2022 1:54 To: <a href="mailto:cuis-dev@lists.cuis.st">Discussion of Cuis Smalltalk</a> Cc: <a href="mailto:JuanVuletich@zoho.com">Juan Vuletich</a>; <a href="mailto:mail@jaromir.net">Jaromir Matas</a> Subject: Re: [Cuis-dev] Freezing UI - can't interrupt via Alt+.<o:p></o:p> </div> <o:p></o:p> On 7/1/2022 9:45 AM, Juan Vuletich via Cuis-dev wrote: <o:p></o:p> <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"> On 7/1/2022 8:17 AM, Jaromir Matas via Cuis-dev wrote: <o:p></o:p> <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"> Hi Juan, all,<o:p></o:p> <o:p></o:p> I wonder why this can’t be interrupted by Alt+.<o:p></o:p> <o:p></o:p> Semaphore new wait<o:p></o:p> <o:p></o:p> The system returns a message “Can not interrupt background process” and the image has to be closed.<o:p></o:p> <o:p></o:p> The same happens in this case:<o:p></o:p> <o:p></o:p> s := Semaphore new.<o:p></o:p> [1/0. s signal] fork.<o:p></o:p> s wait<o:p></o:p> <o:p></o:p> It not only freezes the UI but is not even recoverable…<o:p></o:p> <o:p></o:p> Thanks,<o:p></o:p> jaromir<o:p></o:p> <o:p></o:p> --<o:p></o:p> Jaromír Matas<o:p></o:p> <a href="mailto:mail@jaromir.net">mail@jaromir.net</a><o:p></o:p> <o:p></o:p> </blockquote> Hi Jaromir, The problem is in #handleUserInterrupt, in particular in #processTakingMostCPU. #handleUserInterrupt runs on a high priority process, so the first thing it needs to figure out is which process to interrupt. I wrote that code believing that alt+. would need to interrupt busy code, and it works in that case. It doesn't work if the UI process is waiting and never resumed, as it is not "busy". We need to do better here. I won't be able to work on this for the next few days, but would be very happy if any of you folks suggest / code a solution. Thanks, <o:p></o:p> <pre>-- </pre> <pre>Juan Vuletich</pre> <pre><a href="http://www.cuis-smalltalk.org">www.cuis-smalltalk.org</a></pre> <pre><a href="https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev">https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev</a></pre> <pre><a href="https://github.com/jvuletich">https://github.com/jvuletich</a></pre> <pre><a href="https://www.linkedin.com/in/juan-vuletich-75611b3">https://www.linkedin.com/in/juan-vuletich-75611b3</a></pre> <pre><a href="https://independent.academia.edu/JuanVuletich">https://independent.academia.edu/JuanVuletich</a></pre> <pre><a href="https://www.researchgate.net/profile/Juan-Vuletich">https://www.researchgate.net/profile/Juan-Vuletich</a></pre> <pre><a href="https://patents.justia.com/inventor/juan-manuel-vuletich">https://patents.justia.com/inventor/juan-manuel-vuletich</a></pre> <pre><a href="https://twitter.com/JuanVuletich">https://twitter.com/JuanVuletich</a></pre> </blockquote> Just pushed a fix. Please review it. It is update #5346. Thanks! <o:p></o:p> <pre>-- </pre> <pre>Juan Vuletich</pre> <pre><a href="http://www.cuis-smalltalk.org">www.cuis-smalltalk.org</a></pre> <pre><a href="https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev">https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev</a></pre> <pre><a href="https://github.com/jvuletich">https://github.com/jvuletich</a></pre> <pre><a href="https://www.linkedin.com/in/juan-vuletich-75611b3">https://www.linkedin.com/in/juan-vuletich-75611b3</a></pre> <pre><a href="https://independent.academia.edu/JuanVuletich">https://independent.academia.edu/JuanVuletich</a></pre> <pre><a href="https://www.researchgate.net/profile/Juan-Vuletich">https://www.researchgate.net/profile/Juan-Vuletich</a></pre> <pre><a href="https://patents.justia.com/inventor/juan-manuel-vuletich">https://patents.justia.com/inventor/juan-manuel-vuletich</a></pre> <pre><a href="https://twitter.com/JuanVuletich">https://twitter.com/JuanVuletich</a></pre> <o:p></o:p> </blockquote> <o:p></o:p> <pre>-- </pre> <pre>Juan Vuletich</pre> <pre><a href="http://www.cuis-smalltalk.org">www.cuis-smalltalk.org</a></pre> <pre><a href="https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev">https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev</a></pre> <pre><a href="https://github.com/jvuletich">https://github.com/jvuletich</a></pre> <pre><a href="https://www.linkedin.com/in/juan-vuletich-75611b3">https://www.linkedin.com/in/juan-vuletich-75611b3</a></pre> <pre><a href="https://independent.academia.edu/JuanVuletich">https://independent.academia.edu/JuanVuletich</a></pre> <pre><a href="https://www.researchgate.net/profile/Juan-Vuletich">https://www.researchgate.net/profile/Juan-Vuletich</a></pre> <pre><a href="https://patents.justia.com/inventor/juan-manuel-vuletich">https://patents.justia.com/inventor/juan-manuel-vuletich</a></pre> <pre><a href="https://twitter.com/JuanVuletich">https://twitter.com/JuanVuletich</a></pre> <o:p> </o:p> <o:p> </o:p> </div> </body> </html>