Vm-dev August 2008

vm-dev@lists.squeakfoundation.org

7 participants
10 discussions

Profiling and delay accuracy
by Andreas Raab 06 Aug '11

06 Aug '11

Hi Folks - For a long time now I had this feeling that MessageTally reports pretty bogus results in many situations without being able to precisely track down why this would be the case. Today I was looking at primitiveResponse() and, much to my surprise, noticed that the checkForInterrupts() that used to be there for years is gone (see Squeak3.6 for example which still has it). The sole reason for this check was to get both high delay accuracy and good profiling behavior. Consider this example: fc := FormCanvas on: Display. MessageTally spyOn:[ 1 to: 100 do:[:i| fc fillColor: Color white. fc printString. ]. ]. Using 3.6 this will be measured correctly as: **Tree** 87.5% {243ms} FormCanvas>>fillColor: |87.5% {243ms} GrafPort>>fillRect:offset: | 87.5% {243ms} GrafPort>>copyBits 12.5% {35ms} FormCanvas(Object)>>printString 12.5% {35ms} FormCanvas(Object)>>printStringLimitedTo: whereas the 3.10 reports it as **Tree** 99.6% {670ms} FormCanvas(Object)>>printString 94.9% {639ms} primitives 4.6% {31ms} FormCanvas(Object)>>printStringLimitedTo: I think you can see the problem and just imagine what this does to any cumulative results. I also wonder what that change does to platforms that don't have high-resolution asynchronous timers. This used to be the one place where we would catch timer changes at high resolution and unless the platform forces high resolution timer interrupts asynchronously (by resetting the interrupt counter) we must be loosing a lot in terms of delay accuracy. (it just so happens that the Windows VM *does* do asynchronous timer interrupts so I never noticed this but I'm very curious about the difference on Linux which typically still has pretty bad timer granularity). Any opinions? My feeling is that the timer check should go back in for all of the above reasons. At the very least a quickCheckForInterrupt() is required but I actually think putting the full check back in is worth it. Cheers, - Andreas

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Joys of Squeak-dev image, VM Compiling on MacIntel and Spoon remote OtherBrowsing
by Ken G. Brown 16 Nov '10

16 Nov '10

MacPro OS X 10.4.9 Xcode 2.4.1 Squeak-dev-114-2, VMMaker 2.8b6.1, Squeak 3.8.15beta6U.app, and version 1657 of svn MacOS VM sources, and Spoon v2a12. Downloaded http://www.squeakvm.org/cgi-bin/viewcvs.cgi/ trunk version 1657 for MacOS Ran squeak-dev-beta-114-2.image on Squeak 3.8.15beta6U.app Loaded VMMaker 3.8b6.1 from dev image Universes. Generated vm sources by following instructions in <http://www.squeakvm.org/cgi-bin/viewcvs.cgi/trunk/platforms/Mac%20OS/vm/Doc…> Fought with Xcode wanting to use MacOSX10.3.9.sdk for ppc which was giving an error which was known and documented in the Readme. Finally figured out what Xcode wanted so built universal app just using 10.4.9 sdk. Couple issues: Exupery references remain in sqnamedPrims.h and sqPlatformSpecific.h from svn version 1657, I just commented them out. Notes said: Info-NPSqueak__Upgraded_.plist was to be found in the Developer directory. I could not find it so scammed a info.plist out of John's Squeak 3.8.15beta6U.app vm. Not sure what impact this has. And much, much diddling about figuring out various things... Finally got a build. It's a lot smaller (3.9MB) than John McIntosh's Squeak 3.8.15beta6U.app (8.1MB), and it looks like it is a PowerPC one but at least it runs. I'll look into the Xcode build process some more. Then: Replaced interp.c with Craig's interp.c for Spoon, rebuilt and got a VM with Spoon client stuff. Downloaded Spoon release 2a12. Moved a copy of Flow plugin from within Craig's naiad.app package into a plugins subdirectory where the new spoon client compatible MacIntel universal VM was run from. Followed Craig's Spoon instructions for loading niaid.st and niaid.pr into the 3.10 image (Squeak-dev-114-2) running on the new VM. Did the run spoon.app thing from Spoon.dmg (version 2a12), needs to be done twice if Safari is not running. Got Spoon processor running. Followed instructions again in the Spoon client and lo! Got OtherBrowser browsing the Spoon memory running on processor. Yay Craig! Who do i get to sign my certificate? :) Ken

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How to use Croquet VMMaker
by Matthew Fulmer 29 Apr '09

29 Apr '09

Hi. In anticipation of working on HydraVM, I am trying to test as close a configuration as possible to HydraVM without being hydra. That is, load the nearest ancestor VMMaker and C sources to hydra, and try to make a working VM. This should help ensure that there are no "normal" bugs once I switch to Hydra, only hydra bugs. So, I did that: Here is my setup: - Fedora core 7 on x86 processor - Release 3.9 image/VM from squeak.org - Load FFI from SqueakMap - Load VMMaker-ar.70 from http://jabberwocky.croquetproject.org:8889/Homebase/ - Checkout http://squeakvm.org/svn/squeak/trunk revision 1796 (The nearest ancestor of HydraVM) I pointed VMMaker at the platforms directory in the checkout, and told it to build source in platforms/unix/src. I selected all plugins to be external, but moved FilePlugin and SocketPlugin to be internal. Then I did mkdir unixbuild cd unixbuild ../platforms/unix/config/configure make make fails linking gnu-interp.o: /bin/sh /home/matthewf/squeak/vm/hydravm-trunk-base/unixbuild/libtool --mode=link gcc -g -O2 -fomit-frame-pointer -DLSB_FIRST=1 -export-dynamic -R/usr/local/lib -o squeak vm/vm.a FilePlugin/FilePlugin.a SocketPlugin/SocketPlugin.a disabledPlugins.o version.o -lutil -ldl -lm -lnsl vm/vm.a gcc -g -O2 -fomit-frame-pointer -DLSB_FIRST=1 -o squeak disabledPlugins.o version.o -Wl,--export-dynamic vm/vm.a FilePlugin/FilePlugin.a SocketPlugin/SocketPlugin.a -lutil -ldl -lm -lnsl vm/vm.a -Wl,--rpath -Wl,/usr/local/lib vm/vm.a(gnu-interp.o): In function `primitiveGetWindowLabel': /home/matthewf/squeak/vm/hydravm-trunk-base/unixbuild/vm/gnu-interp.c:15141: undefined reference to `ioGetWindowLabel' vm/vm.a(gnu-interp.o): In function `primitiveSetWindowLabel': /home/matthewf/squeak/vm/hydravm-trunk-base/unixbuild/vm/gnu-interp.c:18770: undefined reference to `ioSetWindowLabelOfSize' collect2: ld returned 1 exit status Building this VM worked when using the latest VMMaker from SqueakMap (VMMaker-tpr.58), everything else the same. Is there something else I need to do in order to build using the Croquet VMMaker? I want to use it specifically, since the Hydra VMMaker is derived from it. The dev notes on Hydra are at http://squeakvm.org/~sig/hydravm/devnotes.html -- Matthew Fulmer -- http://mtfulmer.wordpress.com/ Help improve Squeak Documentation: http://wiki.squeak.org/squeak/808

5 9

Interpreter>>signed32BitValueOf: and signed64BitValueOf: broken
by Andreas Raab 26 Nov '08

26 Nov '08

Hi - I just noticed hat Interpreter>>signed32BitValueOf: and signed64BitValueOf: are broken for edge cases. The following example will illustrate the problem: array := IntegerArray new: 1. array at: 1 put: 16rFFFFFFFF. "should fail but doesn't" array at: 1. "answers -1 incorrectly" array := IntegerArray new: 1. array at: 1 put: -16rFFFFFFFF. "should fail but doesn't" array at: 1. "answers 1 incorrectly" The problem is that both signed32BitValueOf: as well as signed64BitValueOf: do not test whether the high bit of the magnitude is set (which it mustn't to fit into a signed integer). The fix is trivial in both cases - basically all that's needed at the end of both functions is this: "Filter out values out of range for the signed interpretation such as 16rFFFFFFFF (positive w/ bit 32 set) and -16rFFFFFFFF (negative w/ bit 32 set). Since the sign is implicit in the class we require that the high bit of the magnitude is not set which is a simple test here" value < 0 ifTrue:[^self primitiveFail]. negative ifTrue:[^0 - value] ifFalse:[^value] Cheers, - Andreas

4 12

Stdin/stdout/stderr support
by Bert Freudenberg 07 Sep '08

07 Sep '08

I have implemented direct support for std streams: http://squeakvm.org/svn/squeak/branches/olpc/platforms/Cross/plugins/FilePl… This will catch filenames like "/dev/stderr" and connect the real stderr instead (also preventing to close these). This file pattern is in usage already, e.g. http://lists.squeakfoundation.org/pipermail/beginners/2007-April/002268.html In OLPC we used this to log errors (we added FileStream class>>stderr etc.) because SqueakDebug.log is in an unaccessible place, but using the /dev/stderr symlink is broken by the security architecture, so I need to access the actual stderr. Any objections to make this go into the trunk Cross platform dir? - Bert -

3 9

Timezones in LocalePlugin
by Bert Freudenberg 29 Aug '08

29 Aug '08

For OLPC I need a UTC time stamp, and found VM's behaviors to differ widely. All VMs currently report time as local time. To identify those VMs we need a primitive that answers the offset of the VM time from local time. This could nicely fallback to 0 if no LocalePlugin is available. Then we also need a primitive to determine the offset of local time from UTC. The locale plugin currently has three related primitives: ==================================== http://squeakvm.org/svn/squeak/trunk/platforms/Cross/plugins/LocalePlugin/L… /* return in minutes the offset between thisVM and UTC. */ sqInt sqLocGetVMOffsetToUTC(void); /* return in minutes the offset between the currenct timezone and UTC */ sqInt sqLocGetTimezoneOffset(void); /* return true if DST is in use, false otherwise */ sqInt sqLocDaylightSavings(void); ==================================== IMHO these are insufficient, besides they do not work the same on all platforms. Here's what I get in Germany with DST in effect: platform Win Mac Linux vm offset 0 0 -120 timezone 60 120 -120 daylight true true true So VMOffsetToUTC is reported as 0 by Mac and Win - I think that primitive is simply misnamed, which led to the wrong implementation in Linux. If the VM answers local time this should be 0. (we might simply declare the VM is always in local time and get rid of this prim entirely) The TimezoneOffset should be counted EAST of Greenwich, this wasn't really specified in the header so that's why Linux got it wrong (Unix timezones are typically counted West). This *should* include DST adjustment IMHO as Mac and Win do. It really is the offset between local time and UTC. So I propose to redefine the primitives as follows: ==================================== /* return in minutes the offset between local time and this VM. this value plus the time reported by the VM gives local time. 0 indicates VM answers local time. If VM answers UTC, in Berlin in Summer this would be +120 */ sqInt sqLocGetVMOffset(void); /* return in minutes the offset between local time and UTC where positive values are East of Greenwich. e.g., Berlin in Summer is +120 in Winter +60 */ sqInt sqLocGetUTCOffset(void); /* return true if DST is in use, false otherwise */ sqInt sqLocDaylightSavings(void); ==================================== As far as I am aware, nobody used these primitives yet. If renaming is too much hassle we could leave the old wrong names but add the comments as I proposed above, and adjust the behavior. Mac then would already be compliant, Windows is only off by an hour (in Summer?), and I'll fix Linux in the OLPC branch. Comments? - Bert -

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Version update to VMMaker on SqueakSource
by David T. Lewis 17 Aug '08

17 Aug '08

Tim, I committed VMMaker-dtl.87.mcz to the SqueakSource repository, and added a Mantis entry to document it: http://bugs.squeak.org/view.php?id=7154 I'm a bit hesitant to write to the VMMaker repository without prior approval, hence this note. Please let me know if I'm overstepping my bounds. Andreas, The change includes a modification to TCaseStmtNode>>customizeShortCasesForDispatchVar:in:method:, which belongs to you. It should be a safe change, but you may want to check Mantis 7154 if you have a chance. Thanks, Dave

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New VMMaker admin
by tim Rowledge 09 Aug '08

09 Aug '08

I've assigned Dave Lewis as an admin for the Sqeaksource VMMaker project. Please contact him in future if you want to be assigned developer or admin status.

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win32 browser plugin
by Bernd Eckardt 07 Aug '08

07 Aug '08

Hi , the windows browserplugin sources include a ocx and a ocx2 version, can Andreas or someone else explain what the main difference is and what problem could be resolved when using one or the other? Thanks Bernd

2 1

unix related VM mantis reports
by tim Rowledge 07 Aug '08

07 Aug '08

I need some help on a few unix specific mantis reports. http://bugs.squeak.org/view.php?id=7123 http://bugs.squeak.org/view.php?id=7103 http://bugs.squeak.org/view.php?id=1386 and http://bugs.squeak.org/view.php?id=0559 No help means no fixes. tim -- tim Rowledge; tim(a)rowledge.org; http://www.rowledge.org/tim Nice computers don't go down.

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Vm-dev August 2008