Comments on Real Software: Supporting multiple cores

Actually here's another with some excellent id...

2010-04-23T21:46:21.812-05:00

Actually here's another with some excellent ideas

http://developer.apple.com/mac/articles/cocoa/introblocksgcd.html

If you're a member have a read of this. If you...

2010-04-23T18:09:48.342-05:00

If you're a member have a read of this. If you're not you can register for free and read it

http://developer.apple.com/mac/library/documentation/General/Conceptual/ConcurrencyProgrammingGuide/Introduction/Introduction.html

Great article on "multithreading"

Could not edit my previous message. Please ignore ...

2010-04-03T21:59:46.334-05:00

Could not edit my previous message. Please ignore " I am pretty sure no one will request that." :)

Amando

It seems, in my opinion, my comments about LLVM co...

2010-04-03T21:51:27.043-05:00

It seems, in my opinion, my comments about LLVM compiler have opened a new thread on this wonderful blog.

Before going to the nitty gritty, I want to excuse me for not learning English as I would like. My skills are unfortunately not good and can't contribute as I would do in Spanish.

As I commented on my previous answer, previous post, I think RS needs to handle with Preemptive Threads the sooner as possible (My 1st choice, is about DLLs, BTW). While multicore architecture is something is still mastered by only top developers, I believe some work could be done to aid us in getting this new programming approach easier.

I have a project written using preemptive threads in C++ since 1999. Basically their approach is to handle a lot of CPU work in a thread. Debugging C++ threads is a nightmare, and writting for it as well. But basically the problem, IMHO, comes when Thread A changes a var that Thread B don't know has been changed. What I think is called a Deadlock.

Any variable inside the local scope is safe, but any other outside the thread itself must to be locked before changing it's value, as other thread can do some work on it as well. (Basically)

I am still trying to make my C++ thread code safe, but 80% of my code are about changing any single var or object instance that is global. I use criticalsections (Lock/Unlock) every time I change them. RealStudio could do this when using some var being global to avoid another thread doing wrong things. When some change is done globally, let the compiler do it automatically (optional).

Other problems could be warned by a new added feature that aids new developers in warning them that their code could be buggy.

Of course is not going to be an easy task. But in my opinion compilers tend to be very criptic about debugging or helping a non experience developer. The code can be run examining the code, before compiling and warning "Hey! You code is not safe... take this an this approach"

I don't pretend RealStudio to do all the work but it could be useful to help and warn about typical mistakes writing preemptive code. I am pretty sure no one will request that.

I am talking about console/services applications, as I know the problem with GUI apps. But it can be a beginning where we can create Dlls that use all cores and put RS on top of the list and be used by other compilers to do really complex things with the easy of use of RS.

Comms betwen GUI and Services could be done easier via some classes you can write for us ala Autodiscovery one.

My 0.2 cents... hope it helps!

Amando

I've been using this technique to connect, dis...

2010-03-23T06:52:07.979-05:00

I've been using this technique to connect, disconnect and get data from a bluetooth serial connection. With a proper timeout and 'ping' device mechanism it helps dealing with undetected hardware disconnection and avoid the GUI to hang while connecting to the serial device.

Having the IDE help make the marshaling of data be...

2010-03-19T17:28:23.955-05:00

Having the IDE help make the marshaling of data between the main and helper would be good (this is the API between the two and the act of sending and receiving the data between the two)

It's pretty much what Mars wrote in the post I mentioned.

Certainly not trivial - and it is possible for a person to do this manually at the moment. Doing it in a safe generic way in the IDE so you don't have to work so hard to set it up is a great goal - and a ton of work :)

Norm you said: "Global" and "shared...

2010-03-19T12:33:06.365-05:00

Norm you said:
"Global" and "shared" are part of the problems this approach avoids.
----

I'm sorry I don't know the 'right' terminology but lacking a formal computer science background i don't know how to use the right terms.

I mean shared effectively but not in a simple concrete manor.

Global classes meaning having the same definition and that enabling the creation of a mechanism in the language to send instance data of such a global class between helper apps and create a clone of it in the receiving app.

Basically I'm saying are the components of the 'superproject' defines the API between helper apps in a way that is more familiar to most Rb users and takes most of the drugery out of it. making it more accessible.

[quote]
Other processes would be insulated from changes to the data while the process was working, they'd not be able to read old data while the transaction was in progress, etc
[/quote]

I really do think you misread (my fault) the meaning behind what i said. I think i realize the issues in principle and I was not proposing anything different in principle, just in API to make it easier, faster and more approachable to most who are used to writing single apps.

Having the IDE and the language better help us to create, organize and code the architecture of multi-app (main/helper) projects with specific user friendly support would give a huge boost to RB's PERCEIVED power and RADness by many.

- Karen

@Aitch748 if you compile all the helpers ass con...

2010-03-18T22:43:42.513-05:00

@Aitch748
if you compile all the helpers ass console apps with the same version of REALbasic then, for some platforms, its quite possible you can have only a single copy of the dylib / dll.
Console apps are organized slightly differently than GUI apps.

@Karen
"Global" and "shared" are part of the problems this approach avoids.

Making it so processes have to use a very well defined API to share data back and forth is actually a good thing.
In fact a nice design would be to make it so that passing data back and forth was much like a database where you had to start transactions, do work, and then commit / rollback any changes.
Other processes would be insulated from changes to the data while the process was working, they'd not be able to read old data while the transaction was in progress, etc
I'd encourage you to read http://www.redecho.org/2008/12/16/concurrency/ and the related paper from Sun that is mentioned.

Having not done this myself, a perhaps naive seed ...

2010-03-18T16:17:57.609-05:00

Having not done this myself, a perhaps naive seed of an idea occurs to me.

One thing that would help to encourage this type of architecture and increase the power of B would be to have RB build in more high level support for it.

Think of such an architecture supported in the IDE being able to be defined as "super project" where the main app and helper apps are "sub projects" which compile to separate apps in the same folder (or bundle on the mac) using the same libraries.

In the super project. Allow some "super global" classes, constants (and maybe properties) to be defined common to all sub projects.

Then provide language support for sending and receiving copies of instances o these classes between the helper apps, without is having to worry about serialization or communication protocols. ( that support would be why they would be different from external classes included in totally separate projects)

If super global properties are supported. put a transparent mechanism in to safely read and write them .

There are probably other things that would be useful but I can't think of any right now

While this would nor provide anything we could do ourselves (except using the same libraries). this would make using the helper app approach to use multiple core a lot more accessible to more RB users.

- Karen

The downside of this, at least until you get LLVM ...

2010-03-18T07:56:54.553-05:00

The downside of this, at least until you get LLVM baked into REAL Studio, is that each executable has its own copy of the complete framework, so each console app is around a megabyte-and-a-half in size.

Might REAL Software consider a compiler option to compile the framework as a DLL called by each of your executables for a setup like this? (That would save disk space, though I don't know if each program would still require its own copy of the DLL within its process space.)

This approach would also move your architecture to...

2010-03-17T15:29:39.442-05:00

This approach would also move your architecture towards a model-view-controller -design which probably won't hurt anyway.

We've been using this technique to utilize mul...

2010-03-17T15:08:54.055-05:00

We've been using this technique to utilize multiple cores for over a year now and it works quite well. What's really nice is that it scales to many CPUs if the child processes are designed appropriately.