Experimental Physics and
Industrial Control System

zhang hao <[email protected]> · Fri, 17 Dec 1999 15:18:53 +0800 (CST)

---------- Forwarded message ----------
Date: Tue, 14 Dec 1999 19:45:49 +0600 (NSK)
From: Tatiana V. Salikova <[email protected]>
To: john sinclair <[email protected]>
Cc: Tatiana V. Salikova <[email protected]>, [email protected]
Subject: Re: zombie problem at UNIX IOC

Dear Mr. Sinclair,

I am very thankful to you for your e-mails. 
My apologies to you for delay of  answer (11-13 Dec. is holidays in
Russia).

I solved problem of zombie threads by following  way:
"taskSpawn()" executes pthread-detach() call before return().

You can get LynxOS EPICS codes by ftp
sky.inp.nsk.su
user: salikova
passwd: tansalik

epics_LynxOS.x86.tar.gz (It has size 7.9Mb)

As I wrote, Now I test IOC codes.
At N-th reading of PV  "caExample" has next bug.
----------------------------------------------------------------------------------- 
...
root:aiExample1 7.000000
FELsparc> caExample root:aiExample1
root:aiExample1 9.000000
FELsparc> caExample root:aiExample1
root:aiExample1 0.000000
FELsparc> caExample root:aiExample1
root:aiExample1 1.000000
FELsparc> caExample root:aiExample1
root:aiExample1 3.000000
FELsparc> caExample root:aiExample1
CA.Client.Diagnostic..............................................
    Message: "User specified timeout on IO operation expired"
    Severity: "Warning" Context: "ca_pend_io failure"
    Source File: ../caExample.c Line Number: 20
..................................................................
CA.Client.Diagnostic..............................................
    Message: "The request was ignored because the specified channel is
disconnected"
    Severity: "Error" Context: "ca_get failure"
    Source File: ../caExample.c Line Number: 21
Abort (core dumped)

---------------------------------------------------------------------------------------

I shall be grateful if you inform me about your opinion of this bug.

Best Regards,
Tatiana
------------------------------------
Budker Institute of Nuclear Physics
prospekt Lavrentev  11
630090, Novosibirsk, RUSSIA
fax     +7 3832 342163
phone   +7 3832 394977

On Fri, 10 Dec 1999, john sinclair wrote:

> On Wed, 8 Dec 1999, Tatiana V. Salikova wrote:
> 
> > 
> > Dear Sir/Madam,
> > 
> > I have zombie problem at UNIX IOC. 
> > Pthread is analog of VxWorks task. When IOC receives the request for
> > operating with PV,  iocCore spawns the pthreads: "CA event", "CA client".
> > Which is completed by "exit()" call or "return ()", this operation
> > switches pthread in  zombie state. iocCore contains following list of
> > pthreads:
> > 
> 
> As mentioned by Jeff, zombie threads are threads that have exited
> for which the parent has not called pthread_join. One way to prevent
> this is for the parent to call pthread_detach for each child thread.
> Does this work for all pthread implementations? I don't know.
> 
> John Sinclair
> [email protected]
> Oak Ridge National Lab
> 865-576-6362   865-574-1268 (fax)
> 
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System