<div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-size:small">Hi Jaromir,</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jun 27, 2022 at 9:05 AM Jaromir Matas <<a href="mailto:mail@jaromir.net">mail@jaromir.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">
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<p class="MsoNormal">Hi Eliot,</p>
<p class="MsoNormal">The attached version of #signalException fixes the stack issue (MNU) when the extra context returns (#jump takes care if it) - for your review.</p></div></div></blockquote><div><br></div><div class="gmail_default" style="font-size:small">Beautiful. That's a really nice implementation.</div><div class="gmail_default" style="font-size:small"></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div lang="EN-US" style="word-wrap:break-word"><div class="gmail-m_-5175141591949779556WordSection1">
<p class="MsoNormal"><u></u> I have one more question: do you prefer to continue in case of nil suspendedContext or would you rather return (as suggested here)?</p></div></div></blockquote><div><br></div><div class="gmail_default" style="font-size:small">Turns out it should error. The usage that I had in VMMaker was</div><div class="gmail_default" style="font-size:small"></div><div class="gmail_default" style="font-size:small">shutdownModule<br> <doNotGenerate><br> <span class="gmail-Apple-converted-space"> </span>| guiProcess activeProcess |<br> <span class="gmail-Apple-converted-space"> </span>threads ifNil: [^self].<br> <span class="gmail-Apple-converted-space"> </span>(guiProcess := self guiProcess) ~= (activeProcess := Processor activeProcess) ifTrue:<br> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>[guiProcess</div><div class="gmail_default" style="font-size:small"> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>signalException:</div><div class="gmail_default" style="font-size:small"> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>(Notification new tag: #evaluateQuit; yourself).</div><div class="gmail_default" style="font-size:small"> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>Project current spawnNewProcessIfThisIsUI: activeProcess.</div><div class="gmail_default" style="font-size:small"> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>activeProcess terminate].</div><div class="gmail_default" style="font-size:small"> <span class="gmail-Apple-converted-space"> ...</span><br></div><div class="gmail_default" style="font-size:small"><span class="gmail-Apple-converted-space"><br></span></div><div class="gmail_default" style="font-size:small"><span class="gmail-Apple-converted-space">but it is now</span></div><div class="gmail_default" style="font-size:small"><span class="gmail-Apple-converted-space"><br></span></div><div class="gmail_default" style="font-size:small"><span class="gmail-Apple-converted-space"><div class="gmail_default">shutdownModule<br> <doNotGenerate><br> <span class="gmail-Apple-converted-space"> </span>| guiProcess activeProcess |<br> <span class="gmail-Apple-converted-space"> </span>threads ifNil: [^self].<br> <span class="gmail-Apple-converted-space"> </span>(guiProcess := self guiProcess) ~= (activeProcess := Processor activeProcess) ifTrue:<br> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>[guiProcess isTerminated ifFalse:</div><div class="gmail_default"> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>[guiProcess</div><div class="gmail_default"> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>signalException:</div><div class="gmail_default"> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>(Notification new tag: #evaluateQuit; yourself)].</div><div class="gmail_default"> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>Project current spawnNewProcessIfThisIsUI: activeProcess.</div><div class="gmail_default"> <span class="gmail-Apple-converted-space"> </span> <span class="gmail-Apple-converted-space"> </span>activeProcess terminate].</div><div class="gmail_default"> <span class="gmail-Apple-converted-space"> ...</span><br></div><br class="gmail-Apple-interchange-newline"></span></div><div class="gmail_default" style="font-size:small"><span class="gmail-Apple-converted-space"><br></span></div><div class="gmail_default" style="font-size:small"><span class="gmail-Apple-converted-space">and the suspendedContext being nil is no longer an issue.</span></div><div class="gmail_default" style="font-size:small"><span class="gmail-Apple-converted-space"><br></span></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div lang="EN-US" style="word-wrap:break-word"><div class="gmail-m_-5175141591949779556WordSection1">
<p class="MsoNormal"> …</p>
<p class="MsoNormal"> suspendedContext ifNil: [^self error: 'no suspended context!!!!'].</p>
<p class="MsoNormal"></p>
<p class="MsoNormal">Also, #signalException originally didn’t resume suspended processes (mentioned in the comments) but your latest version resumes all immediately; the intended semantics is hard to judge without real experience, so just doublechecking. :)</p></div></div></blockquote><div><br></div><div class="gmail_default" style="font-size:small">I think the explicit check is good, but is perhaps better if it reads self isTerminated. Can you commit to trunk or do you need me to?</div><div class="gmail_default" style="font-size:small"><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div lang="EN-US" style="word-wrap:break-word"><div class="gmail-m_-5175141591949779556WordSection1">
<p class="MsoNormal"><u></u> Many thanks,</p>
<p class="MsoNormal">Jaromir</p></div></div></blockquote><div><br></div><div class="gmail_default" style="font-size:small">You're the one who deserves thanks.</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div lang="EN-US" style="word-wrap:break-word"><div class="gmail-m_-5175141591949779556WordSection1">
<p class="gmail-m_-5175141591949779556MsoNoSpacing"><strong><span style="font-family:"Calibri Light",sans-serif;color:rgb(51,51,51);font-weight:normal">Jaromír Matas</span></strong><span style="font-family:"Calibri Light",sans-serif;color:rgb(85,85,85)"><u></u><u></u></span></p>
<p class="gmail-m_-5175141591949779556MsoNoSpacing"><span style="font-family:"Calibri Light",sans-serif;color:rgb(46,117,182)"><a href="mailto:mail@jaromir.net" target="_blank">mail@jaromir.net</a></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><img width="694" height="2" style="width: 7.2291in; height: 0.0208in;" id="gmail-m_-5175141591949779556Horizontal_x0020_Line_x0020_1" src="cid:181a64d3026af9f1f1c1"><u></u><u></u></p>
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<p class="MsoNormal"><b><span style="color:black">From:</span></b><span style="color:black"> Squeak-dev <<a href="mailto:squeak-dev-bounces@lists.squeakfoundation.org" target="_blank">squeak-dev-bounces@lists.squeakfoundation.org</a>> on behalf of Jaromir Matas <<a href="mailto:mail@jaromir.net" target="_blank">mail@jaromir.net</a>><br>
<b>Sent:</b> Monday, June 27, 2022 10:12:25 AM<br>
<b>To:</b> The general-purpose Squeak developers list <<a href="mailto:squeak-dev@lists.squeakfoundation.org" target="_blank">squeak-dev@lists.squeakfoundation.org</a>><br>
<b>Subject:</b> Re: [squeak-dev] The Trunk: Kernel-eem.1484.mcz</span> <u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="gmail-m_-5175141591949779556xmsonormal">Hi Marcel,</p>
<p class="gmail-m_-5175141591949779556xmsonormal">I think we have oversimplified #signalException.</p>
<p class="gmail-m_-5175141591949779556xmsonormal">It looks like only tests use it in the Trunk (and those test are ok either way) but Eliot apparently has some not-so-happy usages elsewhere.</p>
<p class="gmail-m_-5175141591949779556xmsonormal"> </p>
<p class="gmail-m_-5175141591949779556xmsonormal">My suggestion is attached; unfortunately there are no tests for this functionality so I guess the ultimate criteria is whether it works for Eliot ;)</p>
<p class="gmail-m_-5175141591949779556xmsonormal">Best,</p>
<p class="gmail-m_-5175141591949779556xmsonormal">Jaromir</p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS">--</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><strong><span style="font-family:"Calibri Light",sans-serif;color:rgb(51,51,51);font-weight:normal">Jaromír Matas</span></strong></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span style="font-family:"Calibri Light",sans-serif;color:rgb(46,117,182)"><a href="mailto:mail@jaromir.net" target="_blank">mail@jaromir.net</a></span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"> </p>
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<p class="gmail-m_-5175141591949779556xmsonormal"><b>From: </b><a href="mailto:marcel.taeumel@hpi.de" target="_blank">Marcel Taeumel</a><br>
<b>Sent: </b>Monday, June 27, 2022 9:38<br>
<b>To: </b><a href="mailto:squeak-dev@lists.squeakfoundation.org" target="_blank">squeak-dev</a><br>
<b>Subject: </b>Re: [squeak-dev] The Trunk: Kernel-eem.1484.mcz</p>
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<p class="gmail-m_-5175141591949779556xmsonormal"> </p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Hi Eliot, hi Jaromir --</span></p>
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<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Please resolve this issue ASAP. I did not expect such a commit given that we are in "CODE FREEZE" at this point. A short notice/discussion would have been nice.</span></p>
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<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
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<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Yet, thanks for working on this issue. :-) Can we leave it as is or is another change required?</span></p>
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<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
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<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Best,</span></p>
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<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Marcel</span></p>
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<p style="margin-top:7.5pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(170,170,170)">Am 26.06.2022 23:57:23 schrieb Jaromir Matas <<a href="mailto:mail@jaromir.net" target="_blank">mail@jaromir.net</a>>:</span></p>
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<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Hi Eliot,</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">How about like this:<br>
<br>
signalException: anException</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> "Signal an exception in the receiver process...if the receiver is currently</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> suspended, the exception will get signaled when the receiver is resumed. If
</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> the receiver is blocked on a Semaphore, it will be immediately re-awakened</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> and the exception will be signaled; if the exception is resumed, then the receiver</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> will return to a blocked state unless the blocking Semaphore has excess signals"</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> | oldList |</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> "If we are the active process, go ahead and signal the exception"</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> self isActiveProcess ifTrue: [^anException signal].</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> "Suspend myself first to ensure that I won't run away in the</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> midst of the following modifications."</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> (oldList := myList) ifNotNil: [self suspend].</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">
</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> suspendedContext ifNil: [self error: 'no suspended context!!'].</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> "Add a new method context to the stack that will signal the exception"</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> suspendedContext := Context</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> sender: suspendedContext</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> receiver: self</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> method: (self class lookupSelector: #pvtSignal:)</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> arguments: {anException}.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> "If we are not on a list to be run (i.e. this process is suspended), then when the</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> process is resumed, it will signal the exception"</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> oldList ifNotNil: [self resume]</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black">pvtSignal: anException</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> "Private. This method is used to signal an exception from another</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> process...the receiver must be the active process."</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> "Since this method is not called in a normal way, we need to take care</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> that it doesn't directly return to the caller (because I believe that could</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> have the potential to push an unwanted object on the caller's stack)."</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> | blocker |</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> self isActiveProcess ifFalse: [^self].</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> anException signal.</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> blocker := Semaphore new.</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> [self suspend.</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> suspendedContext := suspendedContext swapSender: nil.</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> self resume] fork.</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> blocker wait.</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black">--</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><strong><span style="font-size:10pt;font-family:"Calibri Light",sans-serif;color:rgb(51,51,51);font-weight:normal">Jaromír Matas</span></strong></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span style="font-size:10pt;font-family:"Calibri Light",sans-serif;color:rgb(46,117,182)"><a href="mailto:mail@jaromir.net" target="_blank">mail@jaromir.net</a></span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
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<p class="gmail-m_-5175141591949779556xmsonormal"><b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">From:
</span></b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"><a href="mailto:mail@jaromir.net" target="_blank">Jaromir Matas</a><br>
<b>Sent: </b>Sunday, June 26, 2022 20:41<br>
<b>To: </b><a href="mailto:squeak-dev@lists.squeakfoundation.org" target="_blank">The general-purpose Squeak developers list</a><br>
<b>Subject: </b>Re: [squeak-dev] The Trunk: Kernel-eem.1484.mcz</span></p>
</div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Hi Eliot,</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">I think the MNU error situation corresponds to the scenario described in pvtSignal:list:; unless I’m mistaken or you find more elegant way I’d suggest to use the
helper method again; fortunately nicely simplified thanks to the new suspend:</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">pvtSignal: anException</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> "Private. This method is used to signal an exception from another</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> process...the receiver must be the active process."</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> "Since this method is not called in a normal way, we need to take care</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> that it doesn't directly return to the caller (because I believe that could</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> have the potential to push an unwanted object on the caller's stack)."</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> | blocker |</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> self isActiveProcess ifFalse: [^self].</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> anException signal.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> blocker := Semaphore new.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> [self suspend.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> suspendedContext := suspendedContext swapSender: nil.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> self resume] fork.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> blocker wait.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">What do you think?</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Best,</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Jaromir</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<div style="border-style:solid none none;border-top-width:1pt;border-top-color:rgb(225,225,225);padding:3pt 0in 0in">
<p class="gmail-m_-5175141591949779556xmsonormal"><b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">From:
</span></b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"><a href="mailto:mail@jaromir.net" target="_blank">Jaromir Matas</a><br>
<b>Sent: </b>Sunday, June 26, 2022 19:03<br>
<b>To: </b><a href="mailto:squeak-dev@lists.squeakfoundation.org" target="_blank">The general-purpose Squeak developers list</a><br>
<b>Subject: </b>Re: [squeak-dev] The Trunk: Kernel-eem.1484.mcz</span></p>
</div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Hi Eliot,</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Thanks for the examples; I have a problem with this one:</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">p := [Semaphore new wait] fork.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Processor yield.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">p signalException: Notification</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">It gives me MNU: UndefinedObject>>wait</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">The reason is:</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">1) you place the new context (Notification signal) on top of the previous suspendedContext (Semaphore new wait); its pc is at the wait.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">2) now when the (Notification signal) context finally returns it places its return value on the top of its senders stack -> and this is a problem because when you
send the wait it takes the stack top as the receiver (but that’s changed in the meantime) if I understand it correctly – resulting in the MNU</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Is this a bug? I’ve never used #signalException so I’m not entirely sure what to expect from it but it behaves differently than in 5.3.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Enclosing a screen snip. If, at that moment, you do suspendedContext pop, the computation will proceed as expected.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">I’ll keep looking at it but wanted to let you know…</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Thanks,</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Jaromir</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span lang="CS" style="font-size:10pt;font-family:Arial,sans-serif;color:black">--</span></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><strong><span style="font-size:10pt;font-family:"Calibri Light",sans-serif;color:rgb(51,51,51);font-weight:normal">Jaromír Matas</span></strong></p>
<p class="gmail-m_-5175141591949779556xmsonospacing"><span style="font-size:10pt;font-family:"Calibri Light",sans-serif;color:rgb(46,117,182)"><a href="mailto:mail@jaromir.net" target="_blank">mail@jaromir.net</a></span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<div style="border-style:solid none none;border-top-width:1pt;border-top-color:rgb(225,225,225);padding:3pt 0in 0in">
<p class="gmail-m_-5175141591949779556xmsonormal"><b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">From:
</span></b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"><a href="mailto:eliot.miranda@gmail.com" target="_blank">Eliot Miranda</a><br>
<b>Sent: </b>Saturday, June 25, 2022 21:12<br>
<b>To: </b><a href="mailto:squeak-dev@lists.squeakfoundation.org" target="_blank">The general-purpose Squeak developers list</a><br>
<b>Subject: </b>Re: [squeak-dev] The Trunk: Kernel-eem.1484.mcz</span></p>
</div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<div>
<div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"> </span></p>
</div>
</div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">On Sat, Jun 25, 2022 at 1:50 AM Jaromir Matas <<a href="mailto:mail@jaromir.net" target="_blank">mail@jaromir.net</a>> wrote:</span></p>
</div>
<blockquote style="border-style:none none none solid;border-left-width:1pt;border-left-color:rgb(204,204,204);padding:0in 0in 0in 6pt;margin:5pt 0in 5pt 4.8pt">
<div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Hi Eliot,</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">I missed that one, sorry.
</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">I’ve just tried this example and only got an assertion error (without your fix):</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">p := [] newProcess suspendedContext: nil.</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">p signalException: Error</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">I just can’t figure out in which case you got the BCR exception :)</span></p>
</div>
</div>
</blockquote>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">In the VMMaker VM simulator, when the simulator window is closed, the closing code attempts to close any and all notifiers & debuggers . I'm working on the threaded
FFI plugin, which in the simulator has multiple Smalltalk processes emulating OS threads. To close each notifier it needs to deliver a tagged Notification signal to the relevant process. Some of these processes are waiting on semaphores. If they are the
old code would suspend, which would set the process's suspendedContext to nil, and result in a cannot return error as the signal was being delivered.</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"> </span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">So the example to test is</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"> </span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">p := [Semaphore new wait] fork.</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">Processor yield.</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">p signalException: Notification</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"> </span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">With the old signalException: version and the new suspend primitive this would crash with the BCR error. Or something like that. Maybe it had to be terminated,
as in</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"> </span></p>
</div>
<div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">p := [Semaphore new wait] fork.</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">Processor yield.</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">p terminate.</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">p signalException: Notification</span></p>
</div>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"> </span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">But you get the idea. If the process's suspendedContext is nil then the context that is put on top of the stack towards the end of signalException: will not be
able to return.</span></p>
</div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"> </span></p>
</div>
<blockquote style="border-style:none none none solid;border-left-width:1pt;border-left-color:rgb(204,204,204);padding:0in 0in 0in 6pt;margin:5pt 0in 5pt 4.8pt">
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<div>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Thanks!</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Jaromir</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<div style="border-style:solid none none;border-top-width:1pt;border-top-color:rgb(225,225,225);padding:3pt 0in 0in">
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">From:
</span></b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"><a href="mailto:commits@source.squeak.org" target="_blank">commits@source.squeak.org</a><br>
<b>Sent: </b>Saturday, June 25, 2022 1:58<br>
<b>To: </b><a href="mailto:squeak-dev@lists.squeakfoundation.org" target="_blank">squeak-dev@lists.squeakfoundation.org</a>;
<a href="mailto:packages@lists.squeakfoundation.org" target="_blank">packages@lists.squeakfoundation.org</a><br>
<b>Subject: </b>[squeak-dev] The Trunk: Kernel-eem.1484.mcz</span></p>
</div>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-right:0in;margin-bottom:12pt;margin-left:19.2pt">
<span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Eliot Miranda uploaded a new version of Kernel to project The Trunk:<br>
<a href="http://source.squeak.org/trunk/Kernel-eem.1484.mcz" target="_blank">http://source.squeak.org/trunk/Kernel-eem.1484.mcz</a><br>
<br>
==================== Summary ====================<br>
<br>
Name: Kernel-eem.1484<br>
Author: eem<br>
Time: 24 June 2022, 4:58:09.258613 pm<br>
UUID: f8ca934f-5875-434a-8cec-4d055099bdb6<br>
Ancestors: Kernel-mt.1483<br>
<br>
Fix a bug in Process>>signalException: where signalling a suspended process would cause a cannot return exception.<br>
<br>
=============== Diff against Kernel-mt.1483 ===============<br>
<br>
Item was changed:<br>
----- Method: Process>>signalException: (in category 'signaling') -----<br>
signalException: anException<br>
"Signal an exception in the receiver process...if the receiver is currently<br>
suspended, the exception will get signaled when the receiver is resumed. If
<br>
the receiver is blocked on a Semaphore, it will be immediately re-awakened<br>
and the exception will be signaled; if the exception is resumed, then the receiver<br>
will return to a blocked state unless the blocking Semaphore has excess signals"<br>
<br>
"If we are the active process, go ahead and signal the exception"<br>
self isActiveProcess ifTrue: [^anException signal].<br>
<br>
"Suspend myself first to ensure that I won't run away<br>
in the midst of the following modifications."<br>
+ self isSuspended ifFalse:<br>
+ [self suspend].<br>
+ suspendedContext ifNil: [self error: 'no suspended context!!!!'].<br>
+ suspendedContext := Context<br>
- self suspend.<br>
- suspendedContext := Context<br>
sender: suspendedContext<br>
receiver: anException<br>
method: (anException class lookupSelector: #signal)<br>
arguments: #().<br>
+ ^self resume!<br>
- ^self resume!</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
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<p class="gmail-m_-5175141591949779556xmsonormal" style="margin-left:19.2pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
</blockquote>
</div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"><br clear="all">
</span></p>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
</div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">--
</span></p>
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<div>
<div>
<div>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">_,,,^..^,,,_</span></p>
</div>
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<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">best, Eliot</span></p>
<p class="gmail-m_-5175141591949779556xmsonormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"> </span></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><span style="font-size:small;border-collapse:separate"><div>_,,,^..^,,,_<br></div><div>best, Eliot</div></span></div></div></div></div>