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About the invariants of a system..
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amin...@gmail.com
Jan 25, 2020, 5:40:11 PM1/25/20
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Hello,
About the invariants of a system..
I was just thinking about Petri nets , and i have studied more
Petri nets, they are useful for parallel programming, and
what i have noticed by studying them, is that there is two methods to prove that there is no deadlock in the system, there is the structural analysis with place invariants that you have to mathematically
find, or you can use the reachability tree, but we have to notice
that the structural analysis of Petri nets learns you more, because it permits you to prove that there is no deadlock in the system,
and the place invariants are mathematically calculated by solving
the following system of the given Petri net:
Transpose(vector) * Incidence matrix = 0
As you will notice those place invariants calculations of the Petri nets
look like Markov chains in mathematics, with there vector of probabilities and there transition matrix of probabilities, and you can, using markov chains mathematically calculate where the vector of probabilities will "stabilize", and it gives you a very important
information, and you can do it by solving the following mathematical system:
vector1 of probabilities * matrix transition of probabilities = vector1 of probabilities.
Solving this system of equations is very important in economics and other fields, and you can notice that it is like calculating the
invariants , because the invariant in the system above is the
vector1 of probabilities, and this invariant, like in the invariants
of the structural analysis of Petri nets, gives you a very important
information about the system, like where market shares will stabilize
that is calculated this way in economics.
Read more my other thoughts:
About reachability analysis of a Petri net..
As you have noticed in my Petri nets tutorial example (read below),
i am analysing the liveness of the Petri net, because there is a rule that says:
"If a Petri net is live, that means that it is deadlock-free."
Because reachability analysis of a Petri net with Tina
gives you the necessary information about boundedness and liveness
of the Petri net. So if it gives you that the Petri net is "live" , so
there is no deadlock in it.
Read more:
Tina and Partial order reduction techniques..
With the advancement of computer technology, highly concurrent systems are being developed. The verification of such systems is a challenging task, as their state space grows exponentially with the number of processes. Partial order reduction is an effective technique to address this problem. It relies on the observation that the effect of executing transitions concurrently is often independent of their ordering.
Tina is using “partial-order” reduction techniques aimed at preventing combinatorial explosion, Read more here to notice it:
http://projects.laas.fr/tina/papers/qest06.pdf
About modelizations and detection of race conditions and deadlocks in parallel programming..
I have just taken further a look at the following project in Delphi called DelphiConcurrent by an engineer called Moualek Adlene from France:
https://github.com/moualek-adlene/DelphiConcurrent/blob/master/DelphiConcurrent.pas
And i have just taken a look at the following webpage of Dr Dobb's journal:
Detecting Deadlocks in C++ Using a Locks Monitor
https://www.drdobbs.com/detecting-deadlocks-in-c-using-a-locks-m/184416644
And i think that both of them are using technics that are not as good
as analysing deadlocks with Petri Nets in parallel applications ,
for example the above two methods are only addressing locks or mutexes
or reader-writer locks , but they are not addressing semaphores
or event objects and such other synchronization objects, so they
are not good, this is why i have written a tutorial that shows my methodology of analysing and detecting deadlocks in parallel applications with Petri Nets, my methodology is more sophisticated because it is a generalization and it modelizes with Petri Nets the broader range of synchronization objects, and in my tutorial i will add soon other synchronization objects, you have to look at it, here it is:
https://sites.google.com/site/scalable68/how-to-analyse-parallel-applications-with-petri-nets
You have to get the powerful Tina software to run my Petri Net examples inside my tutorial, here is the powerful Tina software:
http://projects.laas.fr/tina/
Also to detect race conditions in parallel programming you have to take a look at the following new tutorial that uses the powerful Spin tool:
https://mirrors.edge.kernel.org/pub/linux/kernel/people/paulmck/perfbook/perfbook.html
This is how you will get much more professional at detecting deadlocks and race conditions in parallel programming.
Thank you,
Amine Moulay Ramdane.
About the invariants of a system..
I was just thinking about Petri nets , and i have studied more
Petri nets, they are useful for parallel programming, and
what i have noticed by studying them, is that there is two methods to prove that there is no deadlock in the system, there is the structural analysis with place invariants that you have to mathematically
find, or you can use the reachability tree, but we have to notice
that the structural analysis of Petri nets learns you more, because it permits you to prove that there is no deadlock in the system,
and the place invariants are mathematically calculated by solving
the following system of the given Petri net:
Transpose(vector) * Incidence matrix = 0
As you will notice those place invariants calculations of the Petri nets
look like Markov chains in mathematics, with there vector of probabilities and there transition matrix of probabilities, and you can, using markov chains mathematically calculate where the vector of probabilities will "stabilize", and it gives you a very important
information, and you can do it by solving the following mathematical system:
vector1 of probabilities * matrix transition of probabilities = vector1 of probabilities.
Solving this system of equations is very important in economics and other fields, and you can notice that it is like calculating the
invariants , because the invariant in the system above is the
vector1 of probabilities, and this invariant, like in the invariants
of the structural analysis of Petri nets, gives you a very important
information about the system, like where market shares will stabilize
that is calculated this way in economics.
Read more my other thoughts:
About reachability analysis of a Petri net..
As you have noticed in my Petri nets tutorial example (read below),
i am analysing the liveness of the Petri net, because there is a rule that says:
"If a Petri net is live, that means that it is deadlock-free."
Because reachability analysis of a Petri net with Tina
gives you the necessary information about boundedness and liveness
of the Petri net. So if it gives you that the Petri net is "live" , so
there is no deadlock in it.
Read more:
Tina and Partial order reduction techniques..
With the advancement of computer technology, highly concurrent systems are being developed. The verification of such systems is a challenging task, as their state space grows exponentially with the number of processes. Partial order reduction is an effective technique to address this problem. It relies on the observation that the effect of executing transitions concurrently is often independent of their ordering.
Tina is using “partial-order” reduction techniques aimed at preventing combinatorial explosion, Read more here to notice it:
http://projects.laas.fr/tina/papers/qest06.pdf
About modelizations and detection of race conditions and deadlocks in parallel programming..
I have just taken further a look at the following project in Delphi called DelphiConcurrent by an engineer called Moualek Adlene from France:
https://github.com/moualek-adlene/DelphiConcurrent/blob/master/DelphiConcurrent.pas
And i have just taken a look at the following webpage of Dr Dobb's journal:
Detecting Deadlocks in C++ Using a Locks Monitor
https://www.drdobbs.com/detecting-deadlocks-in-c-using-a-locks-m/184416644
And i think that both of them are using technics that are not as good
as analysing deadlocks with Petri Nets in parallel applications ,
for example the above two methods are only addressing locks or mutexes
or reader-writer locks , but they are not addressing semaphores
or event objects and such other synchronization objects, so they
are not good, this is why i have written a tutorial that shows my methodology of analysing and detecting deadlocks in parallel applications with Petri Nets, my methodology is more sophisticated because it is a generalization and it modelizes with Petri Nets the broader range of synchronization objects, and in my tutorial i will add soon other synchronization objects, you have to look at it, here it is:
https://sites.google.com/site/scalable68/how-to-analyse-parallel-applications-with-petri-nets
You have to get the powerful Tina software to run my Petri Net examples inside my tutorial, here is the powerful Tina software:
http://projects.laas.fr/tina/
Also to detect race conditions in parallel programming you have to take a look at the following new tutorial that uses the powerful Spin tool:
https://mirrors.edge.kernel.org/pub/linux/kernel/people/paulmck/perfbook/perfbook.html
This is how you will get much more professional at detecting deadlocks and race conditions in parallel programming.
Thank you,
Amine Moulay Ramdane.
Chris Vine
Jan 25, 2020, 6:11:23 PM1/25/20
to
On Sat, 25 Jan 2020 14:40:02 -0800 (PST)
amin...@gmail.com wrote:
> Hello,
Goodbye. Petri nets are off topic, this is a C++ newsgroup. Go back to
the newsgroups that you have already turned into a desert, and leave
this one alone.
We could also do without the racist white Arab stuff.
amin...@gmail.com wrote:
> Hello,
Goodbye. Petri nets are off topic, this is a C++ newsgroup. Go back to
the newsgroups that you have already turned into a desert, and leave
this one alone.
We could also do without the racist white Arab stuff.
Sam
Jan 26, 2020, 9:43:16 AM1/26/20
to
Bonita Montero
Jan 26, 2020, 9:51:50 AM1/26/20
to
> We could also do without the racist white Arab stuff.
I'll bet my right hand that Amine is manic-depressive.
He has manic phases where he writes waterfalls and depressive
phases where you won't read anything from him. He should get
a proper treatment.
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