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

Tips and tricks to get a higher score in...
Tank.iois - you guessed it! - another multiplayer arena battler likeAgar.io and Slither.io. It does differentiate itself by putting you in a tiny tank though, so it's not exactly the same. To help you get that all-important high score, we've got a... | Read more »
How to unlock characters in One Tap Tenn...
As the title suggests, One Tap Tennis requires only a single tap to play its particular brand of tennis, and rewards you with a ton of unlockable characters if you perform well. Fortunately for you, we at 148Apps have got a few tips and tricks to... | Read more »
Grab it now: Game Craft’s Legend of War...
The real time strategy game is now available for you to sink your teeth into, through the App Store and Google Play. Combining elements of skill, strategy and empire building, Legend of War is a real gamers’ game. [Read more] | Read more »
Skateboard Party 3 ft. Greg Lutzka (Gam...
Skateboard Party 3 ft. Greg Lutzka 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Skateboard Party is back! This third edition of the popular sports franchise features professional skater... | Read more »
Cubious (Games)
Cubious 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: Cubious – How smart are you? How high is your IQube? Solve the impossible puzzles to find out, and help a lost little cube find his... | Read more »
Goat Simulator Waste of Space (Games)
Goat Simulator Waste of Space 1.1 Device: iOS Universal Category: Games Price: $4.99, Version: 1.1 (iTunes) Description: ** IMPORTANT - SUPPORTED DEVICESiPhone 4S, iPad 2, iPod Touch 5 or better.** | Read more »
Wildfulness - Unwind in nature and calm...
Wildfulness - Unwind in nature and calm your mind with nature sounds and illustrations 1.0 Device: iOS Universal Category: Healthcare & Fitness Price: $1.99, Version: 1.0 (iTunes) Description: Spending time in nature helps you to... | Read more »
Dr. Panda Racers (Education)
Dr. Panda Racers 1.0 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0 (iTunes) Description: STEP ON THE GAS, RACE AND WIN!Fasten your seat belts and get ready to race! Speed your way to the finish line while doing... | Read more »
ROMANCING SAGA 2 (Games)
ROMANCING SAGA 2 1.0.0 Device: iOS Universal Category: Games Price: $17.99, Version: 1.0.0 (iTunes) Description: Romancing SaGa 2, originally released only in Japan in 1993, has been completely remastered and now receives its first... | Read more »
WRIO Keyboard (Utilities)
WRIO Keyboard 1.0 Device: iOS iPhone Category: Utilities Price: $2.99, Version: 1.0 (iTunes) Description: 40% OFF DURING LIMITED INTRODUCTORY OFFER | Read more »

Price Scanner via MacPrices.net

Enterprise Workers Pick Technology Over Perks...
New Adobe study shows surprising attitudes about office jobs and where the future of work is heading. Adobe has released survey findings revealing that a surprising 70 percent of U.S. office workers... Read more
Goal Zero and OtterBox Partner to Expand iPh...
Goal Zero, specialists in portable power, have announced a partnership with OtterBox, brand smartphone case protection, to offer the Slide and Slide Plus Batteries as modules compatible with the new... Read more
15-inch Retina MacBook Pros on sale for up to...
B&H Photo has 15″ Retina MacBook Pros on sale for up to $210 off MSRP. Shipping is free, and B&H charges NY tax only: - 15″ 2.2GHz Retina MacBook Pro: $1799 $200 off MSRP - 15″ 2.5GHz Retina... Read more
Clearance 2015 13-inch MacBook Airs available...
B&H Photo has clearance 2015 13″ MacBook Airs available for $250 off original MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 1.6GHz/4GB/128GB MacBook Air (MJVE2LL/A): $799... Read more
Apple refurbished Apple TVs available for up...
Apple has Certified Refurbished 32GB and 64GB Apple TVs available for up to $30 off the cost of new models. Apple’s standard one-year warranty is included with each model, and shipping is free: -... Read more
21-inch iMacs on sale for up to $120 off MSRP
B&H Photo has 21″ iMacs on sale for up to $120 off MSRP including free shipping plus NY sales tax only: - 21″ 3.1GHz iMac 4K: $1379.99 $120 off MSRP - 21″ 2.8GHz iMac: $1189 $110 off MSRP - 21″ 1... Read more
Kanex Introduces GoPower USB-C Rechargeable B...
Kanex has announced its GoPower USB-C portable battery for the USB-C MacBook, featuring the new industry standard connector and cable used for connectivity and power. Providing users with a new... Read more
Convertible and Detachable Devices Winning Ov...
According to the latest figures published by International Data Corporation (IDC), Western European shipments of ultraslim convertibles and detachables posted positive growth (44.7%) to account for... Read more
New MacBook Pros And Will MacBook Air Be Upgr...
With my mid-2013 13-inch MacBook Air closing on its third anniversary come November, I’m in system upgrade mode. Actually the Haswell CPU equipped Air is still doing a fine job, but my good wife is... Read more
Apple’s Education discount saves up to $300 o...
Purchase a new Mac or iPad using Apple’s Education Store and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free, and... Read more

Jobs Board

Automotive Sales Consultant - Apple Ford Linc...
…you. The best candidates are smart, technologically savvy and are customer focused. Apple Ford Lincoln Apple Valley is different, because: $30,000 annual salary Read more
Service Assistant - *Apple* Chevrolet *App...
Apple Automotive is one of the fastest growing dealer...and it shows. Consider making the switch to the Apple Automotive Group today! At Apple Automotive, we Read more
Editor, *Apple* News - APPLE (United States...
Job Summary The Apple News team is looking for a passionate and knowledgeable editor with experience covering entertainment/pop culture and experience running social Read more
*Apple* Nissan Service Technicians - Apple A...
Apple Automotive is one of the fastest growing dealer...and it shows. Consider making the switch to the Apple Automotive Group today! At Apple Automotive , Read more
ISCS *Apple* ID Site Support Engineer - APP...
…position, we are looking for an individual who has experience supporting customers with Apple ID issues and enjoys this area of support. This person should be Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.