Re: a bug that might be related to BUG #1739

Started by Tom Lanealmost 21 years ago2 messagesbugs
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#1Tom Lane
tgl@sss.pgh.pa.us

Tzahi Fadida <tzahi_ml@myrealbox.com> writes:

I am writing C functions and I use SPI extensively.
Till now I used cursors and there was no memory leaks.
But now I do thousands of inserts using SPI_execp
and I also give it parameters.

If SPI_execp leaked memory then so would almost any plpgsql function,
so I'm inclined to think the leak is in your own code. Post a complete
example if you want it investigated.

regards, tom lane

#2Tzahi Fadida
tzahi_ml@myrealbox.com
In reply to: Tom Lane (#1)

Here it is. It could very well be in my code or a lack of understanding.
I started from scratch and have written a small example.
If it will also appear on your machine you should notice
that you are loosing a few megabites in memory
in a few secs. Maybe I am not freeing something or something like
that or it could be some kind of caching mechnism.
All I know is that when the function finishes the memory is not
released.
And when I exit psql, the memory is released.

p.s: I don't know if its normal but if I don't do spi_freetuptable after
the inserts,
I loose 10 times more memory.

http://rafb.net/paste/results/t2arbb22.html

#include "executor/spi.h"

PG_FUNCTION_INFO_V1(nis);

Datum
nis(PG_FUNCTION_ARGS)
{
SPI_connect();
void *plan;
int ret;
int i;
Datum vals[2];
vals[0]=-1;
vals[1]=-1;
char nuls[2];
nuls[0]=' ';
nuls[1]=' ';
Oid oids[2];
oids[0]=INT4OID;
oids[1]=INT4OID;

if ((plan = SPI_prepare("CREATE TEMPORARY TABLE NIS (a int, b int)",
0, NULL)) == NULL)
elog(ERROR, "SPI_prepare() returns NULL");
if ((ret = SPI_execute_plan(plan, NULL
, NULL, false, 1)) != SPI_OK_UTILITY)
elog(ERROR, "SPI_execute_plan() was no successfull(create)");

if ((plan = SPI_prepare("insert into nis values ($1,$2)", 2,oids ))
== NULL)
elog(ERROR, "SPI_prepare() returns NULL");

for (i=0;i<100*1024;i++){
if ((ret = SPI_execute_plan(plan, vals
, nuls, false, 1)) != SPI_OK_INSERT)
elog(ERROR, "SPI_execute_plan() was no successfull(insert)");
SPI_freetuptable(SPI_tuptable);
}
SPI_finish();
for (i=0;i<2000*1024*1024;i++);
PG_RETURN_INT32(1);
}

Regards,
tzahi.

Show quoted text

-----Original Message-----
From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Sent: Monday, July 04, 2005 12:54 AM
To: Tzahi Fadida
Cc: pgsql-bugs@postgresql.org
Subject: Re: [BUGS] a bug that might be related to BUG #1739

Tzahi Fadida <tzahi_ml@myrealbox.com> writes:

I am writing C functions and I use SPI extensively.
Till now I used cursors and there was no memory leaks.
But now I do thousands of inserts using SPI_execp
and I also give it parameters.

If SPI_execp leaked memory then so would almost any plpgsql
function, so I'm inclined to think the leak is in your own
code. Post a complete example if you want it investigated.

regards, tom lane