TweetFollow Us on Twitter

November 93 - BAMADA Notes

BAMADA Notes

Robert Lenoil

The October BAMADA meeting featured Eric Anderson, author of Apple's Thread Manager package, and Bo Klintberg, author of Software Framework Association's soon-to-be-released OSL Scripting Components product. (There was a September meeting, but I unfortunately couldn't attend, and therefore can't report on the proceedings.)

Thread Manager

The Thread Manager is a Macintosh system extension that provides for multiple threads of execution within a single application. Multi-threaded is all the rage nowadays: Windows NT does it; OS/2 has been doing it; and like so many other "new" features in desktop computer operating systems, many flavors of UNIX have been doing it for years. Now, thanks to the efforts of Eric Anderson and company, you can use the threads model of programming on the Macintosh too.

A thread is a lightweight task within a process that shares all the process's resources (open files, address space, etc.). Basically, a thread is just a private stack and a saved program counter and registers. As context switches go, switching between two threads is fast. When you have a time consuming task to perform or are doing polled or asynchronous i/o, create a separate thread to perform the activity. Periodically or while waiting for i/o, your thread sleeps to allow other threads to run; this lets your program maintain a responsive user interface without the tedious effort of state machine-based background processing from the main event loop, à la MacApp cohandlers or similar mechanisms.

Version 1.2 of Thread Manager is on Apple's November Developer CD. It is not the thread manager described in issue 6 of Apple's d e v e l o p magazine (that thread manager was unsupported and is now obsolete) but the concepts discussed in that article do apply. It can be shipped with your commercial programs for a nominal licensing fee. Also on the developer CD is Voodoo Monkey, a threads-aware debugger (the Debugger from Jasik Designs also knows about Thread Manager); and a utility package that adds semaphores and other features built on top of the basic Thread Manager API.

Thread Manager supports two styles of thread: cooperative and preemptive. Cooperative threads are scheduled at WaitNextEvent time. The default scheduler calls all runnable cooperative threads in a round robin fashion, with special provision for activating the main thread (the initial thread, which will handle your main event loop) whenever an event is available in the OS event queue. Preemptive threads are preemptively multitasked, which means that they run until they yield to another thread or until their time quantum expires. Preemptive threads must follow the rules for code that executes at interrupt time, namely, they cannot call any trap that can cause memory to be moved and they must not call traps where reentrancy is a concern. Preemptive threads are ideal for porting bulky number crunching algorithms to the Macintosh; without any coding changes the main thread will still get processor time and allow the user interface to operate while the computation occurs in the background. Tom Becker demonstrated this technique to the audience with a thread-based version of FracApp, a program which computes and displays the Mandelbrot set.

Threads Manager does have some limitations. For starters, it is only available for applications; not for desk accessories, INITs, or drivers. Thread switching only occurs when the target application is given time by the Process Manager. Since the Process Manager uses a cooperative multiprocessing model, threads - even preemptive ones - can be kept waiting for indefinite periods of time by unfriendly foreground applications. Last, but not least, Eric Anderson announced that preemptive threads will not be supported for native mode applications on PowerPC Macintoshes. So unless you plan on running your applications on PowerPC only in 680x0 emulation mode, you should not use preemptive threads.

OSL Scripting Components

Bo Klintberg spoke to the BAMADA audience as part of his US tour of MADA affiliates. Bo hails from Sweden, where he is hard at work putting the finishing touches on his AppleEvent/AppleScript support library for MacApp. The package is very complete, with a format modeled after MacApp's. It comes with source code (C++), sample apps, an introductory guide, cookbook, class and method reference, 411 help files, and an OSL Scripting Suite reference. The documentation comes to over three hundred pages. Unlike Ken Ryall's MAScript package, which modifies the MacApp source code to add AppleEvent support to existing MacApp classes, OSL Scripting Components leaves the MacApp code untouched and provides a whole new set of classes for dealing with AppleEvents. There are separate classes for client events (which send requests) and server events (which respond to requests). To support a new AppleEvent, your subclass must override the PrepareMessage and ReplyComplete methods; most of the other work is handled for you.

OSL Scripting Components will come with demo applications for an AppleEvent client, an AppleEvent server, and an AppleScript recordable application. In the future, Bo would like to add handlers for the AppleEvent table and database suites. Personally, I wanted him to hurry up and get back to Sweden so that we could get this package sooner; it looks like a winner for AppleEvent and AppleScript programming in MacApp. Hopefully by the time you read this Software Frameworks Association will have announced availability and pricing.

Next time…

BAMADA meets the first Thursday of each month at 7pm at 4 Infinite Loop in Apple's R&D campus in Cupertino. At the November meeting, members of Apple's MacApp team will discuss the upcoming 3.1 release. Also, Tom Becker will be giving a demonstrations on drag and drop, and show a new class that does it for you with no code additions. If you're interested in speaking at an upcoming meeting, or want to be placed on the mailing list for BAMADA announcements, contact Eric Hanig or Tom Becker at ABI.FC (AppleLink), Eric_Hanig@apldbio.com (Internet), or call 800-874-9869 extension 8902.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

5 slither.io mash-ups we'd love to...
If there's one thing that slither.io has proved, it's that the addictive gameplay of Agar.io can be transplanted onto basically anything and it will still be good fun. It wouldn't be surprising if we saw other developers jumping on the bandwagon,... | Read more »
How to navigate the terrain in Sky Charm...
Sky Charms is a whimsical match-'em up adventure that uses creative level design to really ramp up the difficulty. [Read more] | Read more »
Victorious Knight (Games)
Victorious Knight 1.3 Device: iOS Universal Category: Games Price: $1.99, Version: 1.3 (iTunes) Description: New challenges awaits you! Experience fresh RPG experience with a unique combat mechanic, packed with high quality 3D... | Read more »
Agent Gumball - Roguelike Spy Game (Gam...
Agent Gumball - Roguelike Spy Game 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Someone’s been spying on Gumball. What the what?! Two can play at that game! GO UNDERCOVERSneak past enemy... | Read more »
Runaway Toad (Games)
Runaway Toad 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: It ain’t easy bein’ green! Tap, hold, and swipe to help Toad hop to safety in this gorgeous new action game from the creators of... | Read more »
PsyCard (Games)
PsyCard 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: From the makers och Card City Nights, Progress To 100 and Ittle Dew PSYCARD is a minesweeper-like game set in a cozy cyberpunk... | Read more »
Sago Mini Robot Party (Education)
Sago Mini Robot Party 1.0 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0 (iTunes) Description: -- Children's Technology Review Editor's Choice -- | Read more »
How to get a high score in every level o...
Sky Charms is an adorable match three puzzler that provides a decent challenge thanks to its creative level design. It regularly presents something new, forcing you to think on your feet. [Read more] | Read more »
Apestorm: Full Bananas (Games)
Apestorm: Full Bananas 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: ***Launch sale – limited time only!*** Fugitive Apes have taken to the skies in search of revenge after humans have... | Read more »
How to create bigger words in Spellspire
Words have power. At least they do in Spellspire,a game about blasting out magical attacks by making words out of a jumble of letters. And it's a lot of fun. But if you want to be the best, you're going to have to think tactically when you start... | Read more »

Price Scanner via MacPrices.net

Aleratec Releases Mac Software Upgrade for 1...
California based Aleratec Inc., designer, developer and manufacturer of Portable Device Management (PDM) charge/sync products for mobile devices and professional-grade duplicators for hard disk... Read more
Sale! Amazon offers 27-inch iMac, 13-inch 2.9...
Amazon has the 27″ 3.2GHz 5K iMac and the 13″ 3.9GHz Retina MacBook Pro on sale for $300 off MSRP, each including free shipping, for a limited time: - 27″ 3.2GHz/1TB HD 5K iMac (model MK462LL/A): $... Read more
Apple refurbished 13-inch Retina MacBook Pros...
Apple has Certified Refurbished 13″ Retina MacBook Pros available for up to $270 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 13″ 2.7GHz... Read more
13-inch 2.7GHz/128GB Retina MacBook Pro on sa...
Take $200 off MSRP on the price of a new 13″ 2.7GHz/128GB Retina MacBook Pro (model MF839LL/A) at Amazon. Shipping is free: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1099.99 $200 off MSRP Act now if... Read more
Apple refurbished clearance 15-inch Retina Ma...
Apple has Certified Refurbished 2014 15″ 2.2GHz Retina MacBook Pros available for $1609, $390 off original MSRP. Apple’s one-year warranty is included, and shipping is free. They have refurbished 15... Read more
27-inch 5K iMacs on sale for up to $150 off M...
B&H Photo has 27″ 5K iMacs on sale for up to $150 off MSRP including free shipping plus NY sales tax only: - 27″ 3.3GHz iMac 5K: $2199 $100 off MSRP - 27″ 3.2GHz/1TB Fusion iMac 5K: $1849.99 $150... Read more
What Does The Refreshed 12-Inch MacBook Tell...
A lot of commentators are complaining that Apple’s update of the 12-Inch MacBook last week is a bit of a damp squib. I don’t know what they were expecting, since it would be very unlike Apple to do a... Read more
Free Wittify Keyboard Now Available On The Ap...
A team of Harvard Business School students have announced that the Wittify Keyboard, a new app utility for iOS devices, is now available on the Apple App Store. The Wittify keyboard and application... Read more
Apple Reports First Year-Over-Year Quarterly...
Apple on TUesday announced financial results for its fiscal 2016 second quarter ending March 26, 2016. The Company posted quarterly revenue of $50.6 billion and quarterly net income of $10.5 billion... Read more
13-inch 2.7GHz Retina MacBook Pros on sale fo...
Take $130-$150 off MSRP on the price of a new 13″ 2.7GHz Retina MacBook Pro at Amazon. Shipping is free: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1169 $130 off MSRP - 13″ 2.7GHz/256GB Retina MacBook... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Solutions Consultant - Apple (United...
# Apple Solutions Consultant Job Number: 48260200 Phoenix, Arizona, United States Posted: Apr. 22, 2016 Weekly Hours: 40.00 **Job Summary** As an Apple Solutions Read more
Restaurant Manager (Neighborhood Captain) - A...
…in every aspect of daily operation. WHY YOU'LL LIKE IT: You'll be the Big Apple . You'll solve problems. You'll get to show your ability to handle the stress and Read more
Simply Mac *Apple* Specialist- Service Repa...
Simply Mac is the largest premier retailer of Apple products in the nation. In order to support our growing customer base, we are currently looking for a driven Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.