Re: How to build OpenPegasus SDK as single threaded?

:-)  It is nice to learn quotes from Confucius... It is nice when you get
to learn few new things in discussion forums.>!!

On 8 April 2012 12:02, Hwang, Johnny <[email protected]> wrote:

>  There's a java version of sblim. Otherwise, if you insist on sticking
> with pegasus, I really doubt that there are other teams out there using
> pegasus as a single-threaded client. Think hatchet for killing a fly on a
> friend's forehead, as Confucius would say.
>
>
>
> Ugh stupid autocorrect
>
>
> Pranav S <[email protected]> wrote:
>
>
> AFAIK, sublim is linux implementation of CIM/WBEM standards for managing
> resources. I do not see the package having support for multiple platforms
> as Pegasus has. And Pegasus has much better implementation.
>
>
> On 8 April 2012 11:35, Hwang, Johnny <[email protected]> wrote:
>
>> If you're building a client, take a look at sblim or something like that.
>> Pegasus is probably too heavy for your needs.
>>
>>
>> Ugh stupid autocorrect
>>
>>
>> Pranav S <[email protected]> wrote:
>>
>>
>> Hi Kirk,
>>
>> If single threaded library wants to use a multi threaded one, or assume
>> an application binary is linking indirectly to multi threaded one, then the
>> entire build chain has to be built with multi threading enabled. Now as I
>> am more focused towards writing a client side binary, I am not using any of
>> multi threaded piece of code from the Pegasus library. So why should I
>> unnecessarily build multi threaded one? and my client binary will be
>> performing basic operations like enumerations, listing association kind of
>> stuff, and for these operations Pegasus do not create any threads.
>>
>> I agree on what you are saying if I were to focus on a Provider, which
>> will plug into server, serving to the multiple client requests.
>>
>> I still think we need to have switch to enable/disable multi threading.
>>
>> On 7 April 2012 23:40, Kirk Augustin <[email protected]> wrote:
>>
>>>  It is unsafe for a single thread to call a multi-thread, but perfectly
>>> safe for a multi-thread to call a single thread.
>>> Multi-threading is the only safe way a service like Pegasus can call
>>> providers.
>>> If not multi threaded, then one faulty provider can corrupt all
>>> providers, as well as Pegasus, with an infinite deadlock.
>>> On HP UX you can mix multi thread and single thread.
>>>  You just have to careful about singe thread library calling multi
>>> threaded libraries.
>>> Multi-threaded libraries have to call single threaded libraries all the
>>> time.
>>> A single thread library should always be passed data by value instead of
>>> reference, so should never need any synchronization protection.
>>>  That can not possibly be a problem on any system.
>>>
>>>  You are using the multi threading piece of code in Pegasus.
>>> It can not be unused.
>>>  Pegasus is a remote network, communications systems, server, relying
>>> on sockets and an unknown number of provider plug-ins.
>>> It would be virtually inconceivable to imagine a good way that could be
>>> done without multi-threading.
>>> You could greatly increase the number of independent processes instead,
>>> and created more sockets or pipes to try to share data, but multi-threading
>>> is a much better solution to a multi tasking server like this.
>>> Your providers are best compiled as out of process, so have nothing to
>>> do with threading at all.
>>> Threading is only important within Pegasus.
>>> The question of threading really is not relevant because Pegasus is in
>>> control of what it calls, so will do so safely.
>>> All you have to worry about is your providers.
>>>
>>> Kirk Augustin
>>> 11821 NW McNamee Rd
>>> Portland, OR 97231
>>>
>>>  HM: 503-289-4356
>>>
>>>   ------------------------------
>>> *From:* Pranav S <[email protected]>
>>>  *To:* Kirk Augustin <[email protected]>
>>> *Cc:* Devchandra Leishangthem <[email protected]>; "
>>> [email protected]" <[email protected]>
>>> *Sent:* Saturday, April 7, 2012 10:37 AM
>>>
>>> *Subject:* Re: How to build OpenPegasus SDK as single threaded?
>>>
>>> On HP UX we cannot mix single threaded libraries with, multi-threaded
>>> ones. It might cause undefined behaviour.
>>> And, if an application links to multi-threaded library directly or
>>> indirectly, it has to be built with multi-threading (-mt option) enabled.
>>> As I am not using multi threaded piece of code from pegcommon(src/Common),
>>> I am expecting it to be disabled. Why unnecessarily create a dependency on
>>> pthread library? I believe it is good to have a flag in configure files
>>>  for enabling/disabling the multi-threading.
>>>
>>>
>>> On 6 April 2012 22:00, Kirk Augustin <[email protected]> wrote:
>>>
>>>  But if you turned off multi threading in Pegasus, you would create and
>>> ensure the very condition you are concerned about avoiding.
>>> You would cause a single threaded library to be linked with multi
>>> threaded ones.
>>> The only safe solution is to make sure Pegasus is multi treaded, so that
>>> you avoid the possibility of a single threaded library being linked to a
>>> multi threaded one.
>>> There is no risk in a multi threaded library linking to a single
>>> threaded one because a single threaded library gets multiple copies.
>>> Only the other way around is risky.
>>> There is only one copy of a multi threaded library, and you do not want
>>> single threaded libraries linking because then more than one could end up
>>> linking at the same time.
>>>
>>> Kirk  Augustin
>>> 11821 NW McNamee Rd
>>> Portland, OR 97231
>>>
>>>  HM: 503-289-4356
>>>
>>>   ------------------------------
>>> *From:* Pranav S <[email protected]>
>>> *To:* Devchandra Leishangthem <[email protected]>
>>> *Cc:* [email protected]
>>> *Sent:* Friday, April 6, 2012 4:38 AM
>>> *Subject:* Re: How to build OpenPegasus SDK as single threaded?
>>>
>>> I some where read, on HPUX and AIX linking single threaded libraries to
>>> multi threaded causes undefined behaviour. Hence I was trying to to build
>>> openpegasus libs as single threaded. I see libpegcommon uses pthread
>>> library. I would like to know if there is way to turnoff the
>>> multithreading. In HPUX Makefiles I see "-mt" option being used to enable
>>> threads support.
>>>
>>> I see Pegasus/Common has thread pool implementation, which is not always
>>> being used by the applications consuming OenPegasus SDK.
>>> Let me know if I am wrong somewhere.
>>>
>>> Thank You,
>>> Pranav
>>>
>>> On 6 April 2012 16:22, Devchandra Leishangthem <[email protected]>wrote:
>>>
>>> Is there any specifi reason why you wanted to build uni-threaded?
>>> Warm Regards
>>> D>L> Meetei
>>> IBM India System and Technology Lab
>>> EGL -D,Bangalore, India
>>>
>>>
>>>
>>> From:   Pranav S <[email protected]>
>>> To:     [email protected],
>>> Date:   04/06/2012 04:06 PM
>>> Subject:        How to build OpenPegasus SDK as single threaded?
>>>
>>>
>>>
>>> Hello,
>>>
>>> I am trying to explore OpenPegasus SDK and its applications. Currently
>>> the
>>> SDK uses multi threading and links to pthreads library, hence it gets
>>> built
>>> as a multithreaded. I would like to know is it possible to build the
>>> library as single threaded? Do we have provision for that in the
>>> Makefiles.
>>> I tried exploring but did not find anything which tells that it is
>>> possible
>>> to build the library as single threaded one. Because linking a single
>>> threaded library to a multithreaded library can lead to undefined
>>> behaviour.
>>>
>>> --
>>> Thanks,
>>> Pranav
>>>
>>>
>>>
>>>
>>>
>>> --
>>> Thanks,
>>> Pranav
>>>
>>>
>>>
>>>
>>>
>>>
>>> --
>>> Thanks,
>>> Pranav
>>>
>>>
>>>
>>>
>>
>>
>> --
>> Thanks,
>> Pranav
>>
>>
>
>
> --
> Thanks,
> Pranav
>
>


-- 
Thanks,
Pranav