Re: [Cppcms-users] cppcms::service and system(..)

[Christian G. <chr...@gm...>]

2012/9/22 Christian Gmeiner <chr...@gm...>:
> 2012/9/22 Christian Gmeiner <chr...@gm...>:
>> Hi all,
>>
>>
>> I have found some time and I am still working in this issue. The
>> current state is the following:
>>
>> void Service::calibrate()
>> {
>>     // valid session needed
>>     if (!session().is_set("user"))
>>     {
>>         BOOSTER_DEBUG("Service") << __func__ << ") not logged in";
>>         return;
>>     }
>>
>>     // only local host is allowed to do this
>>     if (request().remote_addr() != "127.0.0.1")
>>     {
>>         BOOSTER_DEBUG("Service") << __func__ << ") only on local host
>> - called from " << request().remote_addr();
>>         response().out() << "$.jGrowl(\"" << translate("Touch
>> calibration only allowed on local host") << "\");" << "\n";
>>         return;
>>     }
>>
>>     response().out() << "$.jGrowl(\"" << translate("Starting
>> calibration") << "...\");" << "\n";
>>     BOOSTER_DEBUG("Service") << __func__ << ") doing action";
>>
>>     system("/opt/scripts/set-backlight.sh 0");
>>     system("/opt/scripts/xcalibrate-touch.sh");
>>     system("/opt/scripts/set-backlight.sh 100");
>>
>>     BOOSTER_DEBUG("Service") << __func__ << ") done";
>> }
>>
>>
>> system("/opt/scripts/set-backlight.sh 0"); call works as expected but
>> the whole web apps hangs
>> at the next call:
>> system("/opt/scripts/xcalibrate-touch.sh");
>>
>>
>> -----------------------------------------
>> #!/bin/bash
>> # Invokes touch screen calibrator (x11)
>>
>> export DISPLAY=:0.0
>> BINARY=/opt/xinput_calibrator
>>
>> CALDATA=`$BINARY | grep 'Setting new calibration data:' | cut -d ":"
>> -f 2 | tr -d ' ' | sed 's/,/ /g'`
>>
>> # if CALDATA is empty simply return
>> if [ -z $CALDATA ]; then
>>   exit 0
>> fi
>>
>> # at the moment we store our axis_calib data in
>> # the ID-Register. in some rare cases the
>> # ID-Register is not accessable and we need a
>> # fallback place to store our data.
>> if [ -e /proc/idreg/axis_calib ]; then
>>   echo $CALDATA > /proc/idreg/axis_calib
>> else
>>   echo $CALDATA > /home/vis/.axis_calib
>> fi
>> -----------------------------------------
>>
>> xinput_calibrator can be found here https://github.com/tias/xinput_calibrator
>>
>>
>> At the moment I am not sure whats wrong and how to debug it. maybe someone
>> has an idea.
>>
>
> Here is the syslog output:
>
> May 31 08:00:38 OT tssw: ajax_render: template: touch_display
> chromeless: 1 (base.cpp:79)
> May 31 08:00:38 OT tssw: i18n: current used locale en (base.cpp:88)
> May 31 08:00:38 OT tssw: cppcms_http: GET /keyboard.png (http_api.cpp:251)
> May 31 08:00:38 OT tssw: cppcms_http: GET /favicon.ico (http_api.cpp:251)
> May 31 08:00:41 OT tssw: cppcms_http: POST /tssw/rpc (http_api.cpp:251)
> May 31 08:00:41 OT tssw: cppcms: JSON-RPC Method call:calibrate
> (rpc_json.cpp:162)
> May 31 08:00:41 OT tssw: TsswService: calibrate) doing action (tssw.cpp:73)

I am quite sorry that I need to 'reopen' this thread but .... I do not
get it working :(

I want to run the following demo app from a cppcms app - its based on
http://www.unix.com/programming/60469-runaway-sigalrm-signal-handler.html

#include <stdio.h>
#include <signal.h>
#include <sys/time.h>
#include <fcntl.h>

#include <syslog.h>

void    on_alarm(int);    /* handler for alarm    */
void    on_input(int);    /* handler for keybd    */
int     set_timer( int which, long initial, long repeat );

volatile sig_atomic_t   finished  = 0;

int main( int argc, char * argv[])
{
    int  fd_flags;
    int k = 0;
    struct sigaction newhandler;
    sigset_t         blocked;

    newhandler.sa_handler = on_input;  /* handler function    */
    newhandler.sa_flags   = 0;

    sigemptyset(&blocked);
    newhandler.sa_mask = blocked;
    if ( sigaction(SIGIO, &newhandler, NULL) == -1 )
        perror("sigaction");

    newhandler.sa_handler = on_alarm;  /* handler function    */
    if ( sigaction(SIGALRM, &newhandler, NULL) == -1 )
        perror("sigaction");


    fcntl(0, F_SETOWN, getpid());
    fd_flags = fcntl(0, F_GETFL);
    fcntl(0, F_SETFL, (fd_flags|O_ASYNC));

    set_timer(ITIMER_REAL, 500, 500);


    while( !finished  )    {
       pause();
       printf("still in loop and finished = %d\n", finished);
    }
    return 0;
}
void on_input(int signum)
{
    int  c = getchar();
    if ( c == 'q' )
        finished = 1;
}

void on_alarm(int signum)
{
    static int k = 0;
    syslog(LOG_INFO, "call number %d\n", k++);
}


int set_timer( int which, long initial, long repeat )
{
    struct itimerval itimer;
    long secs;

    // initialize initial delay
    secs = initial / 1000 ;
    itimer.it_value.tv_sec     = secs;
    itimer.it_value.tv_usec    = (initial - secs*1000 ) * 1000 ;

    // initialize repeat inveral
    secs = repeat / 1000 ;
    itimer.it_interval.tv_sec  = secs;
    itimer.it_interval.tv_usec = (repeat - secs*1000 ) * 1000 ;

    return setitimer(which, &itimer, NULL);
}


It should print something like this to syslog

Oct 12 00:01:59 OT xinput_calibrator: call number 0
Oct 12 00:02:00 OT xinput_calibrator: call number 1
Oct 12 00:02:00 OT xinput_calibrator: call number 2
Oct 12 00:02:01 OT xinput_calibrator: call number 3
Oct 12 00:02:01 OT xinput_calibrator: call number 4
Oct 12 00:02:02 OT xinput_calibrator: call number 5
Oct 12 00:02:02 OT xinput_calibrator: call number 6
Oct 12 00:02:03 OT xinput_calibrator: call number 7


If I run this within a json rpc request I via
system("/opt/xinput_calibrator");

void Service::calibrate()
{
    // valid session needed
    if (!session().is_set("user"))
    {
        BOOSTER_DEBUG("Service") << __func__ << ": not logged in";
        return;
    }

    // only local host is allowed to do this
    if (request().remote_addr() != "127.0.0.1")
    {
        BOOSTER_DEBUG("Service") << __func__ << ": only on local host
- called from " << request().remote_addr();
        flash(translate("Touch calibration only allowed on local host"));
    }
    else
    {
        flash(translate("Starting calibration"));
        BOOSTER_DEBUG("Service") << __func__ << ": doing action";
#if 0
        // here comes unix magic
        int master;
        pid_t pid = forkpty(&master, 0, 0, 0);

        if (pid == -1)
        {
            BOOSTER_ERROR("Service") << __func__ << ": pid = " << pid;
            return;
        }
        else if (pid == 0)
        {
            if (execl("/bin/su", "/bin/su", "vis", "-c",
"/opt/scripts/xcalibrate-touch.sh", (char *)0) == -1 )
            {
                BOOSTER_ERROR("Service") << __func__ << ": execlp " << errno;
            }
            BOOSTER_ERROR("Service") << __func__ << ": program exited";
            return;
        }
        BOOSTER_DEBUG("Service") << __func__ << ": Child process: " << pid;
        BOOSTER_DEBUG("Service") << __func__ << ": done";

        // TODO ...
#endif
        //system("/bin/su vis -c /opt/scripts/xcalibrate-touch.sh");
        system("/opt/xinput_calibrator");
    }

    getFlashMessage();
    BOOSTER_DEBUG("Service") << __func__ << ": done";
}


It starts but nothing is in the system log :/ I think its a problem
with the timer stuff..
has anybody an idea... would sponsor a (virtual) beer.

root@OT:~# ps aux | grep xinput
root      2070  0.0  0.0   1792   496 ?        S    00:12   0:00 sh -c
/opt/xinput_calibrator
root      2071  0.0  0.0   1580   248 ?        S    00:12   0:00
/opt/xinput_calibrator
root      2075  0.0  0.1   3820   716 pts/2    S+   00:12   0:00 grep xinput

Other stuff like system("/sbin/reboot"); works...

thanks
---
Christian Gmeiner, MSc