Strange exit behaviour of GUI programs in Xfce on Logout

[Bernhard Walle]

Hello,

following problem: I wrote an application which should save some
information on exit. The application doesn't use session management
(it's very simple, doesn't even have a real GUI, the connection to the
X-Server is only to get closed on logout).

The function that writes the information is registered with atexit(3).
gtk is used for the connection to the X sever.

When using other window managers, all goes fine. I tried KDE, GNOME,
WindowMaker and mwm. Only when using Xfce, the registered function is
not executed. It makes no difference if I use the session manager or the
plain Xfce login script. I use the current stable SVN 4.2.3 of Xfwm4,
the rest is 4.2.2 (tarballs).

I tracked down the problem a bit:

 - Starting a failsave session (only Xterm)
 - xfwm4&
 - ./testclient&
 - exit

=> WORKS

 - Starting a failsave session
 - xfwm4 --daemon
 - ./testclient&
 - exit

=> WORKS NOT

The test program is "attached".

Thanks for help.


Regards,
  Bernhard

================================================
/*
 * Compile with:
 * gcc `pkg-config --cflags --libs gtk+-2.0` \
 * -o testclient testclient.c
 */
#include <stdio.h>
#include <signal.h>
#include <gtk/gtk.h>

void sighandler(int sig)
{
    printf("sig\n");
    gtk_main_quit();
}

void last_action(void *arg)
{
    printf("exit\n");
    FILE* fp = fopen("/tmp/test.txt", "w");
    fprintf(fp, "Test\n");
    fclose(fp);
}

int main(int argc, char *argv[])
{
    gtk_init(&argc, &argv);

    signal(SIGHUP, sighandler);
    signal(SIGTERM, sighandler);
    signal(SIGQUIT, sighandler);
    signal(SIGINT, sighandler);

    atexit(last_action);

    gtk_main();

    return 0;
}
================================================

(The real application is some kind of Bluetooth server to remote-control
Xfmedia from a Java mobile phone. It needs to be started by the Session
manager/.xinitrc to have a connection to D-BUS to Xfmedia. That's the
reason why it isn't a real Unix daemon.)