Multithreading on Mac OS X

IPEnthusiast,

When you open the Terminal, you can type

ps -ax

and list all the processes in Mac OS X as individual threads.

When you read the website from Apple Developer, any programmer following Apple's guidelines will make at least Posix compliant threads if not Cocoa. There are naturally some issues with Carbon programming, stated here:

http://www.macintouch.com/m10carbon.html

So as long as you are running all non-legacy code, you should be good to go.

IPEnthusiast wrote:
Well, simply because Mac OS X is based on UNIX, it can't be assumed that the OS is multithreaded. Multithreading is a concept that came around way after the first UNIX OSes were developed.

Multithreading is mandated by Posix, and OS X 10.5 is fully Posix compliant. In fact it is UNIX 03 registered, and therefore it is Unix. See Mac OS X Leopard: Technology for more.

If you want to know more about threads in OS X, try

man 3 pthread

And this actually manifested itself in earlier versions of the Linux kernel that simulated threads by actually launching a whole process in place of a thread, to take advantage of the process scheduler. Linux was firmly based on old UNIX code, I believe the implementation was called Minix.

On the other hand, Linux and Minix were, and are, not Unix. Neither were "based on" old Unix code.

I might ammend this post saying, there is a Developer forum where you can ask what Mac OS X does support, or how it supports a certain feature, rather than off the bat assume it does not support it. It is found here:

http://discussions.apple.com/forum.jspa?forumID=727

Additionally you can search the resources at http://developer.apple.com/

I found the above link about Thread Local Storage though with the help of Google.

I would encourage to you dispell any myths you've heard, by asking how to approach a technical issue, instead of saying it does not support XYZ.

Mac OS 8 and 9 were multithreading in many tasks, but the application switching was not. Mac OS X offers multithreading at the application level. To see the extent of the threading, your Activity Viewer/Monitor utility (it was renamed with a certain version of Mac OS X) will show you all the separate tasks.

Since you sound like a knowledgeable programmer, I will assume you have installed or will install soon the Developer Tools package. When that is done, go into the /Developer/Applications/Performance Tools/ folder and run Thread Viewer. You will either attach it to an already-running application or use it to start a new application, after which you will get a window where you can see in real time all the threads being used by the chosen application, down to the specific code being executed. Knock yourself out... 😀

Side note: I'd suggest you register yourself on the [Apple Developer Connection|http://developer.apple.com> (there's a free registration option) so you can download the very latest version of the Developer Tools, as well as many other development goodies.

Hi IPEnthusiast;

With OS X being based on Unix, I would have to say that it is multithreaded. It is most certainly more capable of multithreading then anything from M$.

In the years of IT support that I have done, I can't believe how poorly Windows is at multithreading and utilizing multiple CPUs. So many times the customer would for Windows and later we would run Unix on the same server hardware and get significantly better perform simply by migrating off of Windows.

Allan

OS X is a fully multithread-aware operating system. The latest version of Java runs on it, and multithreaded java programs and applets are all fully functional, provided they dont require some OS-specific or hardware-specific resource.

The latest version of Java runs on it,

Not quite true:

http://www.javatester.org/version.html

says the latest version for Mac OS X is:

1.6.0_07-b06-153

Yet

1.6.0_14 is most current. Not that it matters in terms of multithreading, but facts are important.

The latest version of Java does run on Mac OS X 10.5. The fact that the latest version is not yet publicly available is a different matter. Just to clarify that it's an issue of release, not technical capability of the OS. As you say, facts are important.

Hi IPEnthusiast;

You can have any opinion you want. It doesn't matter to me.

I believe as do the others who have posted in reply to your question that Mac OS X is multithreaded. So unless you can produce some proof the the contrary, I am sticking by my original statement.

Allan

Hi IPEnthusiast;

And your point is???

Like any of us really care two cents about anything at all from Microsloth here.

Personally Winders can fall of the edge of the world and I would not care in the least.

Allan

Don't know where you got your information from, but Apple operating systems have been multithreaded since at least OS 8.