Re: How to build OpenPegasus SDK as single threaded?

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