Write to IFS file - high CPU -- C400-L

I have a program that copies a DB2 file into an IFS stream file.
It may process millions of records.
The problem is that the program consumes high CPU (more than 90%). I removed
all the processing and only left the read from the DB2 file and write to the
IFS file functions. The program stack shows the write function almost
constantly so I assume the write function is the one to blame.
What is the best way to implement a solution like that?

Thanks
Boris.

-----Original Message-----
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Today's Topics:

1. Re: digitsof in a declaration (Erik Olsson)
2. Re: digitsof in a declaration (Aaron Albertson)
3. Re: digitsof in a declaration (Erik Olsson)

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

message: 1
date: Tue, 10 May 2011 21:05:24 +0200
from: Erik Olsson <erik.eo.olsson@xxxxxxxxx>
subject: Re: [C400-L] digitsof in a declaration

Thanks (again) Aaron. Should I bother reporting it?

Mark. Sorry if I came across as under researched but I think the code said
both C (in C++ you use bcd.h) and decimal.h.

Thanks,
Erik

On 10 maj 2011, at 17:50, Aaron Albertson <albertaa@xxxxxxxxxx> wrote:

Hi all,

Mark - Erik's code _does_ include decimal.h.

Erik - This appears to be a bug in the C compiler.

These declarations work:

char periodString[digitsof(var)];
char periodString[10 + 1];

but this does not:

char periodString[digitsof(var) + 1];

It appears to be a problem with using the digitsof macro in an expression
on the array declaration.

As a workaround you could just allocate the storage:

char *periodString = (char *)malloc(digitsof(myrec.DECFIELD) + 1);

Thanks,

Aaron Albertson

c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx wrote on 05/10/2011
10:06:25 AM:

From: "Mark S. Waterbury" <mark.s.waterbury@xxxxxxxxxxxxx>
To: C programming iSeries / AS400 <c400-l@xxxxxxxxxxxx>
Date: 05/10/2011 10:10 AM
Subject: Re: [C400-L] digitsof in a declaration
Sent by: c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx

Hi, again, Erik:

Further searching of the InfoCenterI found this:

To use the decimal digitsof, and precisionof macros in your code,
you must specify

#include <decimal.h>

in your ILE C source.

(Did you even _try_ to search for an answer, e.g. in the InfoCenter,
before asking on the C/400 list?)

HTH,

Mark S. Waterbury

On 5/10/2011 10:46 AM, Erik Olsson wrote:
Anyone understand why I can't use the digitsof keyword in a
declaration? It's based on a decimal field in a struct that is known
at compile time so I don't see the problem.

#include<decimal.h>
#include</source/yada/tabledefs/myfile.h>

/* ... */

FLXDXYZ_MYFILE_MYFILE_both_t myrec;

char periodstring[digitsof(myrec.DECFIELD) + 1];

I get this: "Integral constant expression with a value greater than
zero is required"

Best wishes,
Erik

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

message: 2
date: Tue, 10 May 2011 14:43:49 -0500
from: Aaron Albertson <albertaa@xxxxxxxxxx>
subject: Re: [C400-L] digitsof in a declaration

Hi Erik,

If this problem is holding you up in any way that the workaround is
insufficient to address then I would suggest opening an issue with IBM. I
have already informed the compiler team of the issue, so if you don't have
an immediate or urgent need then you don't need to worry about reporting
it.

Aaron Albertson

c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx wrote on 05/10/2011
02:05:24 PM:

From: Erik Olsson <erik.eo.olsson@xxxxxxxxx>
To: C programming iSeries / AS400 <c400-l@xxxxxxxxxxxx>
Date: 05/10/2011 02:08 PM
Subject: Re: [C400-L] digitsof in a declaration
Sent by: c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx

Thanks (again) Aaron. Should I bother reporting it?

Mark. Sorry if I came across as under researched but I think the
code said both C (in C++ you use bcd.h) and decimal.h.

Thanks,
Erik

On 10 maj 2011, at 17:50, Aaron Albertson <albertaa@xxxxxxxxxx> wrote:

Hi all,

Mark - Erik's code _does_ include decimal.h.

Erik - This appears to be a bug in the C compiler.

These declarations work:

char periodString[digitsof(var)];
char periodString[10 + 1];

but this does not:

char periodString[digitsof(var) + 1];

It appears to be a problem with using the digitsof macro in an

expression

on the array declaration.

As a workaround you could just allocate the storage:

char *periodString = (char *)malloc(digitsof(myrec.DECFIELD) + 1);

Thanks,

Aaron Albertson

c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx wrote on 05/10/2011
10:06:25 AM:

From: "Mark S. Waterbury" <mark.s.waterbury@xxxxxxxxxxxxx>
To: C programming iSeries / AS400 <c400-l@xxxxxxxxxxxx>
Date: 05/10/2011 10:10 AM
Subject: Re: [C400-L] digitsof in a declaration
Sent by: c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx

Hi, again, Erik:

Further searching of the InfoCenterI found this:

To use the decimal digitsof, and precisionof macros in your code,
you must specify

#include <decimal.h>

in your ILE C source.

(Did you even _try_ to search for an answer, e.g. in the InfoCenter,
before asking on the C/400 list?)

HTH,

Mark S. Waterbury

On 5/10/2011 10:46 AM, Erik Olsson wrote:
Anyone understand why I can't use the digitsof keyword in a
declaration? It's based on a decimal field in a struct that is known
at compile time so I don't see the problem.

#include<decimal.h>
#include</source/yada/tabledefs/myfile.h>

/* ... */

FLXDXYZ_MYFILE_MYFILE_both_t myrec;

char periodstring[digitsof(myrec.DECFIELD) + 1];

I get this: "Integral constant expression with a value greater than
zero is required"

Best wishes,
Erik

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

message: 3
date: Tue, 10 May 2011 22:06:43 +0200
from: Erik Olsson <erik.eo.olsson@xxxxxxxxx>
subject: Re: [C400-L] digitsof in a declaration

Great Aaron, I can live with the workaround, no problem.

Thanks for your help,
Erik

2011/5/10 Aaron Albertson <albertaa@xxxxxxxxxx>:

Hi Erik,

If this problem is holding you up in any way that the workaround is
insufficient to address then I would suggest opening an issue with IBM. ?I
have already informed the compiler team of the issue, so if you don't have
an immediate or urgent need then you don't need to worry about reporting
it.

Aaron Albertson

c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx wrote on 05/10/2011
02:05:24 PM:

From: Erik Olsson <erik.eo.olsson@xxxxxxxxx>
To: C programming iSeries / AS400 <c400-l@xxxxxxxxxxxx>
Date: 05/10/2011 02:08 PM
Subject: Re: [C400-L] digitsof in a declaration
Sent by: c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx

Thanks (again) Aaron. Should I bother reporting it?

Mark. Sorry if I came across as under researched but I think the
code said both C (in C++ you use bcd.h) and decimal.h.

Thanks,
Erik

On 10 maj 2011, at 17:50, Aaron Albertson <albertaa@xxxxxxxxxx> wrote:

Hi all,

Mark - Erik's code _does_ include decimal.h.

Erik - This appears to be a bug in the C compiler.

These declarations work:

char periodString[digitsof(var)];
char periodString[10 + 1];

but this does not:

char periodString[digitsof(var) + 1];

It appears to be a problem with using the digitsof macro in an

expression

on the array declaration.

As a workaround you could just allocate the storage:

char *periodString = (char *)malloc(digitsof(myrec.DECFIELD) + 1);

? ? ? ? ? ? ? ?Thanks,

Aaron Albertson

c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx wrote on 05/10/2011
10:06:25 AM:

From: "Mark S. Waterbury" <mark.s.waterbury@xxxxxxxxxxxxx>
To: C programming iSeries / AS400 <c400-l@xxxxxxxxxxxx>
Date: 05/10/2011 10:10 AM
Subject: Re: [C400-L] digitsof in a declaration
Sent by: c400-l-bounces+albertaa=us.ibm.com@xxxxxxxxxxxx

Hi, again, Erik:

Further searching of the InfoCenterI found this:

? ? To use the decimal digitsof, and precisionof macros in your code,
you must specify

? ? ? ? #include <decimal.h>

? ? in your ILE C source.

(Did you even _try_ to search for an answer, e.g. in the InfoCenter,
before asking on the C/400 list?)

HTH,

Mark S. Waterbury

On 5/10/2011 10:46 AM, Erik Olsson wrote:
Anyone understand why I can't use the digitsof keyword in a
declaration? It's based on a decimal field in a struct that is known
at compile time so I don't see the problem.

#include<decimal.h>
#include</source/yada/tabledefs/myfile.h>

/* ... ?*/

FLXDXYZ_MYFILE_MYFILE_both_t ? ? ?myrec;

char ?periodstring[digitsof(myrec.DECFIELD) + 1];

I get this: "Integral constant expression with a value greater than
zero is required"

Best wishes,
Erik

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