[jacorb-developer] Delay in serial communication

[Steve Osselton]

Might be worth taking look at what is causing the delay by using some sort
of
Java profiling tool (such as JPROF).

In general Java isn't a great choice for applications that need
deterministic behaviour,
as essentially stuff such as garbage collection makes Java pretty non
deterministic.
Would be better with a C++ ORB (OmniORB/TAO are both free/open source)
or better still a C ORB <blatent plug> such as eORB/C </blatent plug>.

Cheers Steve.

On 26 July 2012 10:53, Kujtim Hyseni <kujtimhyseni at hotmail.com> wrote:

>
> On date 29 March 2012 I posted the following message at JacORB mailing
> list:
>
> "Hello,
>
> for my project I heave developed a class (implementation class) which
> forwards requests (operations) from client to serial port, waits for
> response, receives the response and sends it back to client but it takes a
> long time to perform it. It delays in receiving the response from serial
> port. For communication with serial port I have developed a dedicated class
> which implements Runnable and SerialPortEventListener classes. My class
> communicates serially with 8051 microcontroller. Again, it seems that class
> delays in receiving the byte stream from microcontroller. Microcontroller
> has a built in serial port while my PC uses USB-to-Serial cable. When I
> communicate microcontroller with the class from usual Java program (from
> main() routine) it works fine and it takes less than a second to receive
> the response back.
>
> I did some measurements (100 requests) in two ways. In the first,
> communication class is external and is instantiated from implementation
> class. In the second, communication class is merged with implementation
> class. The results are: for first way average response time 9.33266
> seconds, minimal response time 4.984 seconds while maximal response time
> 18.015 seconds; for second way average response time 8.62625 seconds,
> minimal response time 4.969 seconds while maximal response time 16.015
> seconds. These values are unacceptable for real time applications and raise
> the question for using JacORB further.
>
>
> What do you think and suggest about?"
>
> Then I got various suggestions (from Nick Cross) such: to install JacORB
> 3.0 and provide the code samples.
>
> I now installed JacORB 3.0 and made the same tests, but, received the same
> delays - just to illustrate for 5 requests times are (in seconds): 6.735,
> 12, 8, 7 and 13. When I invoke the requests from usual java program it
> takes less than a second per request - this is normal since routines at
> this phase are void , they just return values.
>
> Again, these delays are unacceptable for out application and if not
> resolved we will abandon JacORB and move to another ORB or perhaps Web
> service technology.
>
> Can someone from JacORB developers or mailing list contributors pay some
> attention and help resolving this issue, in order to continue with my
> project and use JacORB.
>
> Kujtim Hyseni
>
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>



-- 
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