Re: Help needed for the resolution of memory leak
ok Thanks Merlin, I will go through the above specified doc and get back in case of further questions Regards, Sasmit Utkarsh +91-7674022625 On Thu, Jan 18, 2024 at 6:36 AM Merlin Moncure wrote: > On Wed, Jan 17, 2024 at 1:14 PM Sasmit Utkarsh > wrote: > >> Hi Merlin et al. >> >> Below are some couple of observations attached as an "overview_of_code" >> and other attachments "function_def_other_details" and leak sanitizer >> report. Please assist with some clarifications given in overview_of_code >> with (***). Let me know if you need any more information >> > > ***How do we handle for the case clearing when PGresult object is assigned a > pointer to the data of the specified field within the existing PGresult > object? > i.e when SQL_get_tpf_rw() actually completes in each iteration? > > > > It is your responsibility to close PGResult and PGConn objects. Each one > created must be cleaned up. This is basic libpq usage. I suggest studying > the documentation. > > > > Start here: https://www.postgresql.org/docs/current/libpq-exec.html > > Also Study here: https://www.postgresql.org/docs/current/libpq-example.html > > > You should not reuse a pointer unless you have cleared the object first. > > > Is the leak reported due to improper handling of the above case ? or is > it due to some other flow > > Your leaks look mostly due to not cleaning PGResult. However, the real issue > here is you need to learn basic libpq usage a little better...try writing a > smaller program and see when it starts to complain about leaks. > > > merlin > >
Re: Help needed for the resolution of memory leak
On Wed, Jan 17, 2024 at 1:14 PM Sasmit Utkarsh wrote: > Hi Merlin et al. > > Below are some couple of observations attached as an "overview_of_code" > and other attachments "function_def_other_details" and leak sanitizer > report. Please assist with some clarifications given in overview_of_code > with (***). Let me know if you need any more information > ***How do we handle for the case clearing when PGresult object is assigned a pointer to the data of the specified field within the existing PGresult object? i.e when SQL_get_tpf_rw() actually completes in each iteration? It is your responsibility to close PGResult and PGConn objects. Each one created must be cleaned up. This is basic libpq usage. I suggest studying the documentation. Start here: https://www.postgresql.org/docs/current/libpq-exec.html Also Study here: https://www.postgresql.org/docs/current/libpq-example.html You should not reuse a pointer unless you have cleared the object first. Is the leak reported due to improper handling of the above case ? or is it due to some other flow Your leaks look mostly due to not cleaning PGResult. However, the real issue here is you need to learn basic libpq usage a little better...try writing a smaller program and see when it starts to complain about leaks. merlin
Re: Help needed for the resolution of memory leak
Thanks, I'll take a look.
Regards,
Sasmit Utkarsh
+91-7674022625
On Wed, Jan 17, 2024 at 4:12 AM Merlin Moncure wrote:
> On Tue, Jan 16, 2024 at 9:10 AM Sasmit Utkarsh
> wrote:
>
>> Hi Merlin et al.
>>
>> I have tried to have the above change added in the missing places. Still,
>> I see the below leaks reported by the address sanitizer. Please see
>> the attachments for the leak reported and the function definition updated.
>> Not sure for PQexecPrepared if we call PQclear(res) for cleaning up as
>> well. let me know if you need any more information
>>
>
> You have many other leaks.See code below, you are making up to thee
> sequential calls to create a result before calling clear. *All *calls
> creating and returning returning PGresult have to be cleared before the
> pointer is reused.
>
> merlin
>
>
>
> LOG_DEBUG("%s() conninfo=%s",__func__,conninfo);
>
> if(is_shadow_db)
> {
> shadow_db_conn = PQconnectdb(shadow_db_conn_info);
> if ( PQstatus(shadow_db_conn ) != CONNECTION_OK )
> {
> LOG_ERROR("Connection to shadow database failed! %s",
> PQerrorMessage(conn));
> PQfinish(shadow_db_conn);
> exit(1);
> }
> *res *= PQexec(shadow_db_conn, "SET bytea_output = 'escape'");
> LOG_DEBUG("%s() Connection to shadow_shc_data database
> SUCCESSFUL",__func__);
> // execute_stored_procedure(shadow_db_conn);
> }
>
> conn = PQconnectdb(conninfo);
> if ( PQstatus(conn) != CONNECTION_OK ) {
> LOG_ERROR("Connection to database failed! %s",
> PQerrorMessage(conn));
> PQfinish(conn);
> exit(1);
> } else {
> *res =* PQexec(conn, "SET bytea_output = 'escape'");
> LOG_DEBUG("%s() Connection to shc_data database
> SUCCESSFUL",__func__);
> }
>
> *res *= PQexec(conn, "START TRANSACTION");
> if (PQresultStatus(res) != PGRES_COMMAND_OK)
> {
> LOG_ERROR("START TRANSACTION failed: %s", PQerrorMessage(conn));
> SQL_exit_nicely(conn,res);
> }
> PQclear(res);
>
>
Re: Help needed for the resolution of memory leak
On Tue, Jan 16, 2024 at 9:10 AM Sasmit Utkarsh
wrote:
> Hi Merlin et al.
>
> I have tried to have the above change added in the missing places. Still,
> I see the below leaks reported by the address sanitizer. Please see
> the attachments for the leak reported and the function definition updated.
> Not sure for PQexecPrepared if we call PQclear(res) for cleaning up as
> well. let me know if you need any more information
>
You have many other leaks.See code below, you are making up to thee
sequential calls to create a result before calling clear. *All *calls
creating and returning returning PGresult have to be cleared before the
pointer is reused.
merlin
LOG_DEBUG("%s() conninfo=%s",__func__,conninfo);
if(is_shadow_db)
{
shadow_db_conn = PQconnectdb(shadow_db_conn_info);
if ( PQstatus(shadow_db_conn ) != CONNECTION_OK )
{
LOG_ERROR("Connection to shadow database failed! %s",
PQerrorMessage(conn));
PQfinish(shadow_db_conn);
exit(1);
}
*res *= PQexec(shadow_db_conn, "SET bytea_output = 'escape'");
LOG_DEBUG("%s() Connection to shadow_shc_data database
SUCCESSFUL",__func__);
// execute_stored_procedure(shadow_db_conn);
}
conn = PQconnectdb(conninfo);
if ( PQstatus(conn) != CONNECTION_OK ) {
LOG_ERROR("Connection to database failed! %s",
PQerrorMessage(conn));
PQfinish(conn);
exit(1);
} else {
*res =* PQexec(conn, "SET bytea_output = 'escape'");
LOG_DEBUG("%s() Connection to shc_data database
SUCCESSFUL",__func__);
}
*res *= PQexec(conn, "START TRANSACTION");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
LOG_ERROR("START TRANSACTION failed: %s", PQerrorMessage(conn));
SQL_exit_nicely(conn,res);
}
PQclear(res);
Re: Help needed for the resolution of memory leak
On Mon, Jan 15, 2024 at 11:32 AM Sasmit Utkarsh
wrote:
> Hi Team,
>
> I am trying to test a code which basically tries to read some data from
> postgresql db in a loop through a function SQL_get_tpf_rw() whose
> definition and other details are shared in the attached file along with the
> memory leak report resulted during testing. Could you let me know if i
> missed calling anywhere PQclear()
> in SQL_get_tpf_rw() which resulted in the below .
>
> Last few lines from the report
>
>
yep: for example,
if (PQresultStatus(*res*) != PGRES_TUPLES_OK)
{
LOG_ERROR("SELECT failed: %s", PQerrorMessage(conn));
LOG_DEBUG("ROLLBACK TRANSACTION AND CHAIN");
*res* = PQexec(conn,"ROLLBACK TRANSACTION AND CHAIN");
LOG_ERROR("INVALID_FILE_ADDRESS %08X",fa);
rc = ERR_INVALID_FILE_ADDRESS;
See highlighted bits. You're reusing the res object before clearing
it. there may be other cases, but this jumped off the page.
merlin
