<div dir="ltr"><div>Running SqueakDebug.app in lldb, I get:</div><div><br></div><div>Process 61332 stopped<br>* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x18)<br> frame #0: 0x09f17c07 Squeak3D`b3dMainLoop(state=0x09f1928c, stopReason=0) at b3dMain.c:1407:32<br> 1404 if(fillList->firstFace) {<br> 1405 /* Note: We fill *including* leftX and rightX */<br> 1406 int leftX = (leftEdge->xValue >> B3D_FixedToIntShift) + 1;<br>-> 1407 int rightX = (rightEdge->xValue >> B3D_FixedToIntShift);<br> 1408 B3DPrimitiveFace *topFace = fillList->firstFace;<br> 1409 <br> 1410 if(leftX < 0) leftX = 0;<br>Target 0: (Squeak) stopped.<br>(lldb) print rightEdge<br>(B3DPrimitiveEdge *) $0 = 0x00000000<br>(lldb) print leftEdge<br>(B3DPrimitiveEdge *) $1 = 0x0617a49c<br>(lldb) bt<br>* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x18)<br> * frame #0: 0x09f17c07 Squeak3D`b3dMainLoop(state=0x09f1928c, stopReason=0) at b3dMain.c:1407:32<br> frame #1: 0x09f0cb23 Squeak3D`b3dStartRasterizer at Squeak3D.c:1704:12<br> frame #2: 0x05d01398<br> frame #3: 0x00002f52 Squeak`interpret at gcc3x-cointerp.c:2749:3</div><div><br></div><div>So why rightEdge is a null pointer?</div><div>If you already examined the code, you may have an idea...<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le sam. 28 déc. 2019 à 22:55, Nicolas Cellier <<a href="mailto:nicolas.cellier.aka.nice@gmail.com">nicolas.cellier.aka.nice@gmail.com</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Hi Stephane,</div><div>I confirm that I can reproduce the crash with an up-to-date VM (on OSX).<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le sam. 28 déc. 2019 à 19:20, Stéphane Rollandin <<a href="mailto:lecteur@zogotounga.net" target="_blank">lecteur@zogotounga.net</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> <br>
Hello all,<br>
<br>
For my first post on this list, I would like to submit the bug that <br>
prevents one of my game (this one: <br>
<a href="http://www.zogotounga.net/comp/guardians.htm" rel="noreferrer" target="_blank">http://www.zogotounga.net/comp/guardians.htm</a>) to work reliably.<br>
<br>
I spent quite some time on this, and I ended up with a nice and concise <br>
way to crash the Squeak3D plugin. The image is available at:<br>
<br>
<a href="http://www.zogotounga.net/swap/crashlab3.zip" rel="noreferrer" target="_blank">http://www.zogotounga.net/swap/crashlab3.zip</a><br>
<br>
Instructions to crash the VM are detailed therein.<br>
<br>
The 3D scene is very simple, there are only three objects. The crash<br>
seems related to a race condition, because inserting a simple delay in<br>
the code prevents it - this is detailed in the image itself.<br>
<br>
I have spent days studying the Smalltalk code, and could not see<br>
anything wrong with what is sent to the plugin. It looks to my<br>
uninformed eyes as a problem of shared memory, where one rasterizing<br>
operation messes up with another happening in parallel (although no<br>
processed is being forked on the Smalltalk side).<br>
<br>
<br>
Stef<br>
</blockquote></div>
</blockquote></div>