Re: How to build OpenPegasus SDK as single threaded?

Hey, anyone agree with me? need for Single Threaded Pegasus libraries?


On 8 April 2012 12:12, Pranav S <[email protected]> wrote:

> :-)  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
>
>


-- 
Thanks,
Pranav