Calling QSqlDatabase::addDatabase from not main thread causes SIGSEGV

[Lesiok]

Show how are You using this class.

[ander.pijoan]

///////////////////////////////////////////////////////// MAIN.CPP
 
PostgresDriver* driver = new PostgresDriver("localhost" , 5432 , "database" , "user" , "user" , "main");
 
QListIterator<QSqlRecord> i( driver->executeQuery( "SELECT * FROM WHATEVER" ) );
    while( i.hasNext() ){
}
driver->deleteLater();

///////////////////////////////////////////////////////// MAIN.CPP

PostgresDriver* driver = new PostgresDriver("localhost" , 5432 , "database" , "user" , "user" , "main");

QListIterator<QSqlRecord> i( driver->executeQuery( "SELECT * FROM WHATEVER" ) );
    while( i.hasNext() ){
}
driver->deleteLater();

To copy to clipboard, switch view to plain text mode 

Works perfectly.

Now:

///////////////////////////////////////////////////////// AGENT.H
 
class Agent : public QObject
{
    Q_OBJECT
public:
    Agent(QString class_name = "Agent");
    ~Agent();
 
    // GETTERS
    unsigned int getId();
    QString getClass();
 
slots:
    virtual void start();
    virtual void end(){this->deleteLater();}
 
private:
 
    // INCREMENTAL FOR IDS
    static unsigned int counter;
 
    unsigned int id;
    QString class_name;
};
 
///////////////////////////////////////////////////////// AGENT.CPP
 
#include "Agent.h"
 
unsigned int Agent::counter = 0;
 
Agent::Agent(QString class_name) : QObject()
{
    this->id = ++Agent::counter;
    this->class_name = class_name;
    this->setObjectName( QString("%1%2").arg( this->getClass() ).arg( this->getId() ) );
}
 
Agent::~Agent() {
    this->thread()->deleteLater();
}
 
unsigned int Agent::getId(){
    return this->id;
}
 
QString Agent::getClass(){
    return this->class_name;
}
 
void Agent::start(){
    PostgresDriver* db = new PostgresDriver("localhost" , 5432 , "database" , "user" , "user" , this->objectName() ); //CRASHES
}
 
///////////////////////////////////////////////////////// MAIN.CPP
 
        Agent* agent = new Agent("Car");
        QThread *thread = new QThread( );
        agent->moveToThread( thread );
        agent->connect( thread, SIGNAL( started() ), agent, SLOT( start() ) );
        thread->start();

///////////////////////////////////////////////////////// AGENT.H

class Agent : public QObject
{
    Q_OBJECT
public:
    Agent(QString class_name = "Agent");
    ~Agent();
  
    // GETTERS
    unsigned int getId();
    QString getClass();

slots:
    virtual void start();
    virtual void end(){this->deleteLater();}

private:

    // INCREMENTAL FOR IDS
    static unsigned int counter;

    unsigned int id;
    QString class_name;
};

///////////////////////////////////////////////////////// AGENT.CPP

#include "Agent.h"

unsigned int Agent::counter = 0;

Agent::Agent(QString class_name) : QObject()
{
    this->id = ++Agent::counter;
    this->class_name = class_name;
    this->setObjectName( QString("%1%2").arg( this->getClass() ).arg( this->getId() ) );
}

Agent::~Agent() {
    this->thread()->deleteLater();
}

unsigned int Agent::getId(){
    return this->id;
}

QString Agent::getClass(){
    return this->class_name;
}

void Agent::start(){
    PostgresDriver* db = new PostgresDriver("localhost" , 5432 , "database" , "user" , "user" , this->objectName() ); //CRASHES
}

///////////////////////////////////////////////////////// MAIN.CPP

        Agent* agent = new Agent("Car");
        QThread *thread = new QThread( );
        agent->moveToThread( thread );
        agent->connect( thread, SIGNAL( started() ), agent, SLOT( start() ) );
        thread->start();

To copy to clipboard, switch view to plain text mode 

Crashes when creating a PostgresDriver inside the Agent.

[jefftee]

Why don't you create the connection from your thread? i.e. your start slot?