memory leak in libpq , definitely lost: 200 bytes in 1 blocks, indirectly lost: 2,048 bytes in 1 blocks ...

#include <errno.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <stdint.h>

#include <unistd.h>

#include <limits.h>

#include <fcntl.h>

#include <termios.h>

#include <time.h>

#include <stdbool.h>

#include <libpq-fe.h>

// gcc -o db_test.o -c -I/usr/include/postgresql db_test.c

// gcc -o db_test db_test.o -lpq

//-------------------------------------------------------------------------------------------------------------------------------//

int main(void)

{

 PGconn *pg_conn = NULL;

 PGresult *res = NULL;

 ConnStatusType status = CONNECTION_BAD;

 

 const char *conninfo = "host = 192.168.0.20 port = 20000 dbname = dbtest user = postgres password = postgres application_name = app-test";

  if((pg_conn = PQconnectdb(conninfo)) != NULL)

  {

   fprintf(stdout, "\n -CP00- \n");

   if(PQstatus(pg_conn) != CONNECTION_OK)

   {

  fprintf(stdout, "\n -CP01-[%d]- \n", PQstatus(pg_conn)); 

 

    do

    {

  sleep(2); 

     PQreset(pg_conn); 

  status = PQstatus(pg_conn); 

  fprintf(stdout, "\n -CP02-[%d]- \n", status);

    }

    while(status != CONNECTION_OK);

   }

   fprintf(stdout, "\n -CP03-[%d]- \n", PQstatus(pg_conn));

  

   res = PQexec(pg_conn, "SELECT 1 AS a");

   PQclear(res); res = NULL;

  

   

   PQfinish(pg_conn); pg_conn = NULL;

  }

 

 return(0);

}

//-------------------------------------------------------------------------------------------------------------------------------//

 

 

 STEP_1_ON-THE-APP-SERVER - compile the application

  gcc -o db_test.o -c -I/usr/include/postgresql db_test.c

  gcc -o db_test db_test.o -lpq

{  

  STEP_2_ON-THE-DB-SERVER - stop PostgreSQL

  sudo service postgresql stop

  STEP_3_ON-THE-APP-SERVER - run the application

  valgrind --leak-check=full --show-reachable=yes --leak-resolution=high -v ./db_test > ./log.log 2>&1

  STEP_4_ON-THE-DB-SERVER - wait [N] seconds (N is a random chosen number between 10-3000) and start PostgreSQL 

} Repeat several times to get the leak

Valgrind options:

--22352--    --leak-check=full

--22352--    --show-reachable=yes

--22352--    --leak-resolution=high

--22352--    -v

--22352-- Contents of /proc/version:

--22352--   Linux version 4.4.0-36-generic (buildd@lcy01-01) (gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.2) ) #55-Ubuntu SMP Thu Aug 11 18:01:55 UTC 2016

--22352-- 

==18777== 2,048 bytes in 1 blocks are indirectly lost in loss record 282 of 290

==18777==    at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)

==18777==    by 0x4E4A1C9: ??? (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4E4A87C: ??? (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4E541A4: ??? (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4E48396: PQconnectPoll (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4E488ED: ??? (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4E495C7: PQreset (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4009FB: main (in /home/puffy/bkserver/pg_db_test_bug00/db_test)

==18777== 2,248 (200 direct, 2,048 indirect) bytes in 1 blocks are definitely lost in loss record 283 of 290

==18777==    at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)

==18777==    by 0x4E4A5DC: PQmakeEmptyPGresult (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4E54161: ??? (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4E48396: PQconnectPoll (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4E488ED: ??? (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4E495C7: PQreset (in /usr/lib/x86_64-linux-gnu/libpq.so.5.8)

==18777==    by 0x4009FB: main (in /home/puffy/bkserver/pg_db_test_bug00/db_test)

==18777== LEAK SUMMARY:

==18777==    definitely lost: 200 bytes in 1 blocks

==18777==    indirectly lost: 2,048 bytes in 1 blocks

==18777==      possibly lost: 0 bytes in 0 blocks

==18777==    still reachable: 93,928 bytes in 2,899 blocks

==18777==         suppressed: 0 bytes in 0 blocks

==18777== 

==18777== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

==18777== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)