BUG #7841: Multithreading in libpq is not working - Mailing list pgsql-bugs

The following bug has been logged on the website:

Bug reference:      7841
Logged by:          Joanna Biernat-Gerono
Email address:      biernatj@interia.pl
PostgreSQL version: 9.2.2
Operating system:   Windows 7
Description:        =


Sample code that provides to access violation (I am using the latest libpq
that is compiled with multithread support, connection was made to two
different dbs). The code is below:

#define WINNT_OS
#include <Windows.h>
#include <iostream>
#include "libpq-fe.h"
#include <signal.h>

#define STD__NULL     NULL
#define STD__SUCCESS  0
#define STD__FAILED   -1
#define STD__FAIL     -1

#define TIMEOUT 100
using namespace std;

volatile bool m_bLicenseCheckedOut =3D false;

enum status
{
       idle, =

       running,
       stop,
       done
} m_running =3D idle;

int m_renewalTime =3D 0;
HANDLE m_hThread =3D NULL;
HANDLE m_hEvent =3D NULL;

DWORD WINAPI threadProc(LPVOID lpvoid)
{    =


    int step =3D 0;
    while(m_running =3D=3D running) {       =


    PGconn       *conn;
    =

    try {                     =


        const char *keys[]=3D{"dbname", "user", "password", "host", "port",
"sslcert", "sslkey", "sslrootcert", "sslmode", NULL};
        const char *values[]=3D{"put_value_here",  "put_value_here" ,
"put_value_here" , "put_value_here" , "put_value_here" , "put_value_here",
"put_value_here", "put_value_here" ,"verify-full", NULL};
        =

       // conn =3D PQconnectdbParams(keys,values,0);

        //conn =3D PQsetdbLogin("put_value_here", "put_value_here", NULL,
NULL, "dbname=3Dput_value_here sslcert=3Dput_value_here sslkey=3Dput_value_=
here
sslrootcert=3Dput_value_here sslmode=3Dverify-full",  "put_value_here" ,
"put_value_here");
        conn =3D PQsetdbLogin("put_value_here", "put_value_here", NULL, NUL=
L,
"put_value_here",  "put_value_here" , "put_value_here");
        long status =3D PQstatus(conn);
        =

        if (status =3D=3D CONNECTION_OK) {

           cout << "\nSuccessfully connected to DB:"<<step++ <<" ";
           Sleep(1);
        } else {

          cout << "\nNot connected to ATR_DB";
          cout << PQerrorMessage(conn);

        }


        } catch (...) {
          cout << "Exception caught";
        }

        if(STD__NULL !=3D conn)
        {
            =

            PQfinish(conn); =

            conn =3D STD__NULL;
        }

        //wait before renewing again
       // WaitForSingleObject(m_hEvent, TIMEOUT);
    =

    }
    m_running =3D done;
    return STD__SUCCESS;

}

/*
void handler(int sig) {

    printf("Signal %d\n",sig);

}
*/

int DoSelect(int step)
{

    PGconn *conn;
       =

    char conninfo[] =3D "dbname=3Dput_value_here host=3Dput_value_here
port=3Dput_value_here user=3Dput_value_here password=3Dput_value_here
sslmode=3Dverify-full sslcert=3Dput_value_here sslkey=3Dput_value_here
sslrootcert=3Dput_value_here" ;


   // conn =3D PQsetdbLogin("put_value_here", "put_value_here", NULL, NULL,
"dbname=3Dput_value_here sslmode=3Dverify-full sslcert=3Dput_value_here
sslkey=3Dput_value_here sslrootcert=3Dput_value_here",  "put_value_here",
"put_value_here");
   conn =3D PQsetdbLogin("put_value_here", "put_value_here", NULL, NULL,
"put_value_here",  "put_value_here", "put_value_here");
   // conn =3D PQconnectdb(conninfo);
   // long status =3D 1;                        =

    long status =3D PQstatus(conn);
    int r =3D PQisthreadsafe();

    if (status =3D=3D CONNECTION_OK)
    {

       cout << "\nSuccesfully connected to MOTOLM DB: "<< step <<" \n";

    } else {

       cout << "\nNot connected to MOTOLM DB\n";
       cout << PQerrorMessage(conn);

    }

    if(STD__NULL !=3D conn)
    {
       =

        PQfinish(conn); =

        conn =3D STD__NULL;
    }
       return 0;
}

int main (int argc,char** args)
{

//    int ts =3D PQisthreadsafe();

//    cout << "PQisthreadsafe =3D " << ts;
    //typedef void (*SignalHandlerPointer)(int);
    //SignalHandlerPointer previousHandler;
    //previousHandler =3D signal(SIGSEGV, handler);   // install our handler

    cout << "PROGRAM STARTED"<< endl;

    m_hEvent =3D CreateEvent(0,false,0,0);
    if (NULL =3D=3D m_hEvent)
    {
        cout << "CreateEvent FAILED" << endl; =

        return STD__FAILED;
    }

    m_running =3D running;
    m_hThread =3D CreateThread(NULL, 0, threadProc, 0,0, NULL);
    if (NULL =3D=3D m_hThread)
    {
        m_running =3D done;
        cout << "CreateThread FAILED" << endl; =

        return STD__FAILED;
    }

    if( FALSE =3D=3D SetThreadPriority(m_hThread,
THREAD_PRIORITY_TIME_CRITICAL))
    {
        cout << "SetThreadPriority FAILED" << endl; =

        return STD__FAILED;
    }
    =

    int i =3D 0;

    while (i < 5000) {
        =

        DoSelect(i++);
        Sleep(1);

    }

    m_running =3D stop;

    cout << "done." << endl;

    return STD__SUCCESS;

}