WINDOWS does not support multithreading concurrent and real-time structures. What an irony !.The most popular OS does not allow systems and structures which can control the most breathtaking technologies of the day. Aerospace , trains, nuclear power plants and other state of the art embedded technologies cannot use WINDOWS !
When I learned about Real-Time and Concurrent Systems ,it was not very acceptable that Microsoft would make such a redundant OS. A bit of dabbling on the internet led me to Article Number 22523 in Microsoft knowledge base.
Fig1. Article 22523
Which clearly stated that ,
"In no sense can Microsoft Windows be considered a "real-time" system. It is a message-driven, event-polling system, with nonpreemptive scheduling".
Being initiated in Windows and using it for about ten years , did make me stubborn and I tried to look for other alternatives which would allow to construct real-time structures in Windows.
Cygwin came to my rescue ! However on running threads in POSIX and tasks in Ada, I realised that it is only a cheap makeover.
Python and Ada however worked in windows , Ada because it is a concurrent language and platform is not an issue. Python did execute the threads , though on a closer inspection it revealed that Python reduces the concurrent codes to their sequential evil twin brother.
A simple code which which prints out 'Hello World' and the thread number ;
Fig 2. The threading code
Fig 3. Execution in Ubuntu
The order of execution of the threads is 3,4,1,5,2 then 1,2,3,4,5 and then 5,4,3,2,1. Thus the order of execution is non-deterministic , typical of real-time systems.
However on Windows ,
Fig 4. Execution in Windows, 'evil twin brother'
When I learned about Real-Time and Concurrent Systems ,it was not very acceptable that Microsoft would make such a redundant OS. A bit of dabbling on the internet led me to Article Number 22523 in Microsoft knowledge base.
Fig1. Article 22523
"In no sense can Microsoft Windows be considered a "real-time" system. It is a message-driven, event-polling system, with nonpreemptive scheduling".
Being initiated in Windows and using it for about ten years , did make me stubborn and I tried to look for other alternatives which would allow to construct real-time structures in Windows.
Cygwin came to my rescue ! However on running threads in POSIX and tasks in Ada, I realised that it is only a cheap makeover.
Python and Ada however worked in windows , Ada because it is a concurrent language and platform is not an issue. Python did execute the threads , though on a closer inspection it revealed that Python reduces the concurrent codes to their sequential evil twin brother.
A simple code which which prints out 'Hello World' and the thread number ;
Fig 2. The threading code
gives slightly different results with different OS. When run on Ubuntu Linux ,
Fig 3. Execution in Ubuntu
However on Windows ,
Fig 4. Execution in Windows, 'evil twin brother'
the order of execution is deterministic , as seen above. Thus windows prevents the real-time characteristics of non-determinism and reduces it to sequential processes.
Linux confirms the standard characteristics of concurrency as nondeterminism and preemption , hence a joy for all concurrent programmers. Seems Bill Gates got it wrong this time !
Linux confirms the standard characteristics of concurrency as nondeterminism and preemption , hence a joy for all concurrent programmers. Seems Bill Gates got it wrong this time !
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