RE: FW: write failure occuring in writeScanRecInProgress function(after writing header) in saveData.c (sscan-2-6-6 module)

[Jay Steele <jsteele@xradia.com>]

Hi Mark and Tim,

     I'm not entirely clear yet on how saveData works, but I'm working with cygwin as a host environment to cross-compile the vxWorks target image using the gcc-vxWorks cross-compiler. I believe that saveData is executing on vxWorks, creating a NFS mount to my Windows computer, successfully creating a scan file on the Windows computer, successfully writing out the header info to this file, then getting an error while executing the xdr_setpos function. Since the file write was unsuccessful, the code starts over to write out to the file 9 more times and then gives up.

 

Tim - let me know if you come up with any other tests I can do to illuminate the source of this problem with xdr_setpos. In the meantime, I'll continue inspecting the saveData.c source code and trying to debug the code on my own. One thought - since xdr_setpos is a UNIX-type function, could this be a problem with the Windows filesystem? Has anybody ever tested scanning with a Windows NFS mount file?

 

     I appreciate your rapid tech-talk feedback late at night and early in the morning.

 

Thanks,

Jay Steele

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From: Mark Rivers [rivers@cars.uchicago.edu]
Sent: Wednesday, November 03, 2010 4:21 AM
To: Tim Mooney; Jay Steele; EPICS tech-talk
Subject: RE: FW: write failure occuring in writeScanRecInProgress function(after writing header) in saveData.c (sscan-2-6-6 module)

Tim and Jay,

 

I'm confused.  Jay's original message said: 

 

"... start the scan and the vxWorks terminal reports the following (with debug_saveData =10, debug_saveDataMsg=10)"

"...  I'm using epics-3-14-11 with VxWorks and compiling with cygwin on windows-x86."

 

Which implies that Jay has saveData running on vxWorks. But I think Tim is talking about a possible problem arising from the Cygwin switch to the new xdr code (tirpc), which should not affect cross-compiling Cygwin to vxWorks, only code running locally on Cygwin?

 

Mark

 

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From: tech-talk-bounces@aps.anl.gov on behalf of Tim Mooney
Sent: Wed 11/3/2010 1:51 AM
To: Jay Steele; EPICS tech-talk
Subject: Re: FW: write failure occuring in writeScanRecInProgress function(after writing header) in saveData.c (sscan-2-6-6 module)

Jay, This is trouble, though I don't know why xdr_setpos() is returning an error.  I've found
on the web indications that others have had trouble with xdr_setpos() not working on
some streams (ref http://linux.die.net/man/3/xdr_setpos) but I haven't found out why.
It may simply be that folks neglected to implement the function in the xdr library, when
they switched cygwin over to new code.

If worse comes to worst, I could recode saveData so it does the xdr writes "by hand",
instead of relying on an xdr library. But I'd like to find out more before doing that.

Tim

On 11/2/2010 6:21 PM, Jay Steele wrote:

Yes - xdr_setpos is returning 0. What does this mean?

 

Thanks,

Jay Steele

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From: Jay Steele
Sent: Tuesday, November 02, 2010 3:51 PM
To: Tim Mooney
Cc: tech-talk@aps.anl.gov
Subject: RE: write failure occuring in writeScanRecInProgress function (after writing header) in saveData.c (sscan-2-6-6 module)

Hi Tim,

    The function is exiting out of this block of code (I added the printf("write failed\n") line).

 

****************************************************************

if (pscan->old_npts < pscan->npts) {
  writeFailed |= !xdr_setpos(&xdrs, pscan->dims_offset);
  Debug3(2, "saveData:writeScanRecInProgress:(%s) scan_dim=%d, dims_offset=%ld\n",
   pscan->name, pscan->scan_dim, pscan->dims_offset);
  if (writeFailed) {
            printf("write failed\n");
            goto cleanup;
        }
  lval = pscan->npts;
  writeFailed |= !xdr_long(&xdrs, &lval);
 }

*****************************************************************

 

Cheers,

Jay Steele

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From: Tim Mooney [mooney@aps.anl.gov]
Sent: Tuesday, November 02, 2010 3:47 PM
To: Jay Steele
Cc: tech-talk@aps.anl.gov
Subject: Re: write failure occuring in writeScanRecInProgress function (after writing header) in saveData.c (sscan-2-6-6 module)

Jay,
The next thing saveData wants to do, after the last message you've shown,
 is to call xdr_setpos(), and I'm pretty sure this will be its first  call to xdr_setpos()
for the file.  I'll guess xdr_pos() is returning an error (zero).  Can you check to see
if this is true?

Tim Mooney

Jay Steele wrote:

Hi EPICS tech-talk,

     I'm having a problem executing my first simple 1D scan here at XRadia. I set up the scan as simply as I could - with one positioner and one data source (SIS 3820 board with input to channel #9 from a signal generator). I am using TPMAC records (e.g., bkgfix1pcs_scanrec_v3.db and AssyGeneric_scanrec_v3.db to set up records) for the positioner. I verified that the SIS 3820 record works to count the pulses from the signal generator, and also that I can move the motor simply by setting 21:D3:BNP:XY:PX:RqsPos. I start the scan and the vxWorks terminal reports the following (with debug_saveData =10, debug_saveDataMsg=10) and keeps trying to write to the scan file without success. Attached is a screen shot of the MEDM interface for the scan. I'm using epics-3-14-11 with VxWorks and compiling with cygwin on windows-x86.

 

saveDataTask: MSG_SCAN_PXNV, ix=0, val=2.000000
21:D3:BNP:scan1 MSG_SCAN_PXNV(2)= 0.000000
saveDataTask: MSG_SCAN_PXNV, ix=0, val=0.000000
21:D3:BNP:scan1 MSG_SCAN_PXNV(0)= 0.000000
saveDataTask: MSG_DESC, val=
MSG_DESC()= 0.000000

 nb_scan_running=1
saveDataTask: MSG_SCAN_DATA, val=0
proc_scan_data(21:D3:BNP:scan1):entry:pmsg->val=0
scan started: 21:D3:BNP:scan1
Checking number of valid positioner
Checking number of valid detector
Checking number of valid trigger
Outermost scan
proc_scan_data(21:D3:BNP:scan1):New file
saveData: stat returned -1 for filename '/data/Nov-1-2010/test_0008.mda'; errno=
3145730
saveData:writeScanRecInProgress: Opening file '/data/Nov-1-2010/test_0008.mda'
saveData:writeScanRecInProgress: Writing file header
saveData:writeScanRecInProgress: scan_dim=1
saveData:writeScanRecInProgress:(21:D3:BNP:scan1) scan_dim=1, dims_offset=0
saveData:writeScanRecInProgress: File Header written
saveData:writeScanRecInProgress: Writing per-scan header
saveData:writeScanRecInProgress: Save scan info
saveData:writeScanRecInProgress: Pos[0] info
saveData:writeScanRecInProgress: Det[0] info
saveData:writeScanRecInProgress: Trg[0] info
saveData:writeScanRecInProgress: Allocate space for Pos[0]
saveData:writeScanRecInProgress: Allocate space for Det[0]
saveData:writeScanRecInProgress:(21:D3:BNP:scan1) scan_dim=1, dims_offset=0

    

     From this output, I tracked the problem down to a write failure in the writeScanRecInProgress function in saveData.c. This occurs after the function writes out the file header and allocates space for Pos[0] and Det[0].

 

     I'm confused why there would be a write failure at this point. Can anybody determine from this problem what might be wrong with my setup to cause this problem?

 

Thanks,

Jay Steele

XRadia Corporation

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-- 
Tim Mooney (mooney@aps.anl.gov) (630)252-5417
Software Services Group (www.aps.anl.gov)
Advanced Photon Source, Argonne National Lab

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-- 
Tim Mooney (mooney@aps.anl.gov) (630)252-5417
Software Services Group, Advanced Photon Source, Argonne National Lab.

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The information in this email, including any attachments, is confidential and intended only for the recipient(s) listed. Any use of this email for any other purpose is prohibited. If you have received this email in error, please notify me immediately by reply email, delete this email, and do not disclose its contents to anyone.