Folks -

I have just issued 11 new updates.  Beyond sundry fixes, this includes John McIntosh's rewrite of Mac Sockets to support Open Transport.  It should run compatibly with earlier VMs, but if you fetch or build a new VM, you will be able to take advantage of the new Socket implementation and support for Open Transport.  The new (backward-compatible) VM can be found in the 2.8 folder on the UIUC server, called
	SqueakVM2.8beta3.sea

John will probably post further information about the new Sockets.  It would be great to get some early testing, both so we can fix any bugs and so we can find out whether the substantially better benchmarks make a real difference "out in the field".

Enjoy
	- Dan
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2300AsyncFile-failComment

2301TurtleTrailMods-di -- Dan Ingalls -- 23 May 2000
Makes batched pen trails work depending on the setting of a preference.
Also pen trails work in the world as well as in any other PasteUp.
Most important, pen trails now work for embedded objects with arbitrary flexing.

2302BigTextFixes-di -- Dan Ingalls -- 7 June 2000
Changes NewParagraph>>selectionRectsFrom:to: to return a single rectangle for all lines between the first and last when the container is a simple rectangle.  This changes the time to display a full selection in a megabyte file from over 10 seconds to about 1/4 second.
Changes CharacterBlock copy to do a simple shallowCopy.  It had been inheriting deepCopy from Rectangle, thus making an unneeded copy of the entire text as well.  Greatly improves typing into a megabyte file.

2303resetExtent-raa -- Bob Arning -- 8 June 2000
Recent changes to #showScrollBar and #hideScrollBar in 2282HiddenScrollBar-dew have unfortunate side-effects for users of retractable scrollbars - they send #extent: whenever the scrollbar is hidden or shown. This leads to:
- long pauses when leaving a text pane with lots of text in which there is a selection
- shifting the contents so that the selection is visible.
I think both (certainly the first) are undesirable. This change set sends #extent: only when the scrollbars are inboard."

2304FXColorFixes -- Andreas Raab -- 8 June 2000
A bunch of fixes for external forms with non-squeak RGBA formats. Found and fixed on the new demo laptop which uses a neat 5x6x5 RGB format in 16 bit depth. Very good for testing.

2305sketchThumbnail-sw -- Scott Wallace -- 9 June 2000
Further chasings of ones own tail regarding the pursuit of consistent dockup of morph and player in the presence of TransformationMorphs...  When a new Sketch was drawn in a quite large painting area, the painting system was often returning a spurious,  nonzero but vanishingly small (order of 1E-14) forward-direction, resulting in the premature launching of an unwanted TransformationMorph for the newborn -- the result of round-off error when computing forward-direction.  This workaround simply maps such spurious tiny offsets returned from the painting system back to zero, which appears to avoid the problem of plain gray thumbnails, which can be traced to this situation."

2306HQTextures -- Andreas Raab -- 9 June 2000
The change set allows the definition of explicit high quality textures when using Morphs as a texture in 3D. The need for such high quality textures comes from the (unfortunate) requirement of all current 3D hardware to deal with textures that are powers of two only. Although that's kinda stupid we gotta play by their rules here.
The dilemma occurs when considering a morph which is, say, 384 at 384 wide. Downsampling to 256 at 256 does require less space (good for limited VRAM/AGP resources on the card) but can lead to bad, bad distortions. Upscaling to 512 at 512 on the other hand requires four times as much space. But it looks just beautiful then. So with this change set we have a choice of what to use and the tradeoffs are made explicit with a new menu entry in the Wonderland wrapper morphs.
As a side effect, the change set introduces a method for scaling arbitrary forms through the best available method (which is using bilinear interpolation if possible, and if not, to use WarpBlt instead).
" 

2307JMM-SemaTableAndLessInt -- johnmci at smalltalkconsulting.com -- 7 June 2000
When I was building a high performance tcp/ip test server I found a number of problems with the external interrupt interface. The first problem is the table at 25 elements is too small, I had test cases that triggered upto 216 interrupts. The second issue was the signalSemaphoreWithIndex: method consolidated semaphores, so two calls on the same semaphore might become one call. This isn't how the Semaphore logic work in the Squeak Class. The third and more difficult problem to solve is that the code used to populate the table and reading from the table is not thread safe. As Squeak is reading from the table then setting the counter to zero you can be busy placing elements in the table via interrupt driven routines. The more complicated fix is to use a OS thread safe queue. The less complicated solution is to use a dual buffered array. This fix uses the dual buffered array. Two arrays of 500 are created and alternate usage based on who is read and who is writting. This should limit problems with interrupt driven code attempting to place items in a array that is being itterated over. In this solution signalExternalSemaphores iternates over the array that isn't active, the signalSemaphoreWithIndex: routine places items in the active array without fear of stomping on the signalExternalSemaphores logic. 
Note of course you can still exceed the 500 element fixed limit and loose interrupts, but of course you could compile a new VM with a larger limit.
I also discovered various race conditions on the access to the externalSemaphore table. This new class uses class side methods to restrict access using a mutex semaphore. It seemed cleaner to deligate the reponsibility here versus adding more code and another class variable to SystemDictionary 
Note that in Smalltalk recreateSpecialObjectsArray we still directly play with the table.
Lastly on the faster machines of today I found that checkForInterrupts was being called well over a thousand times per second. If there is no interrupt activity or other extraordinary events then a simple counter is used to dicate how often the call should be made. Problem is machines are so fast now that the original 1000 counter start value is too small. This change attempts to use feedback to dictate the number of calls to about 200 per second (perhaps too high?) As time progresses it attempts to make the counter start number float to a optimistic value. Clock overFlows, long delays etc should not drastically affect the algoritmn, we still limit the lower end to 1000. On a PowerBook 500Mhz the value floated between 5200 and 10500, and gave me a 2% improvement in bytescodes per second.
Note that interruptChecksEveryNms is the target delay between calls, this value is in milliseconds, to use a different value you must then build a new VM.
Beware if your implementation's millisecond clock doesn't record in resolutions of at least 5 milliseond increments. If for example your clock will only give you 1/60 of a second accuracy this change set will cause problems. in this case change interruptChecksEveryNms to 0 to keep the historical behavior when you are building your VM"

2308JMM-Socket-Changes -- John M McIntosh -- 5 June 2000
A number of changes were made to NetNameResolver and Socket when I was creating the Macintosh Open Transport plugin. These changes range from adding some accessors to get at instance variables to a fundamental change in semaphore signalling logic.
We now have three semaphores: one for open/close/listen, one for reading, one for writing. Existing applications and existing C code are unaffected by this change since I attempted to make this change backwards compatible. However this change makes mult-threaded applications safer to write since you now can have seperate processes in a application that have the responsiblity for listening, reading, and writing to a socket. Implementation of this feature depends on the underlying VM implementation. As of June 5th 2000 it is fully supported on the Macintosh. Beware you can of course write a Squeak application that will not behave correctly on an older VM. Use the accessor primitiveOnlySupportsOneSemaphore to find out if the C code supports one or three semaphores and make a decision about continuing.
Additional support for UDP was added, now you can set the host for an outgoing UDP datagrams, and on reading a UDP datagram get information about who it came from, this support of course relies on the underlying VM implementation. Although this feature was support somewhat in the in the previous implementation we now tie host information to the datagram which ensures race conditions or high volume UDP traffic from multiple locations does not affect who we think we are talking to.
Support for setting and getting Socket, TCP/IP, and UDP options was added.  You should be able to set or get information about socket options for all of the common options and most of the uncommon ones. Again support relies on the underlying VM implementation.
Lastly some cleanup of the test examples and new examples were added, but for testing purposes you should use the SUnit test suite that I created to run tests when making socket C code changes or changes to the Classes"

2309JMM-PLG-New-Mac-Socket

2310JMM-MacCcodeChangesForOT