Hi there I don't think you need to "daemonize" the process manually as the native service infrastructure handles that for you. IIRC you can sit in the loop on the Main thread. Here's an example of a USB Device hotplug listener I wrote a while back which ran as a system service.
https://github.com/trevd/android_external_hotplugd/blob/ics/hotplug.c However if you actually do want to daemonize the process you can add oneshot to the service declaration which will tell init to only start the service once, e.g service rsgd /system/bin/rsgd oneshot class main user system Hope that helps! trevd On Wednesday, 4 June 2014 05:11:30 UTC+1, rsg wrote: > > I need to write a Linuxland daemon that talks to our custom hardware. I > would like to use the /init process to start, and if necessary, restart it. > I have made this entry into the init.<hardware>.rc file that looks like > this: > > service rsgd /system/bin/rsgd > class main > user system > > Here is my daemon (just a skeleton now, but it runs): > > #include <sys/types.h> > #include <sys/stat.h> > #include <stdio.h> > #include <stdlib.h> > #include <fcntl.h> > #include <errno.h> > #include <unistd.h> > #include <syslog.h> > #include <string.h> > > #define DAEMONIZE > > > int main(void) > { > > #ifdef DAEMONIZE > > pid_t pid, sid; > > /* Fork off the parent process */ > pid = fork(); > if (pid < 0) { > exit(EXIT_FAILURE); > } > /* Exit the parent process. */ > if (pid > 0) { > exit(EXIT_SUCCESS); > } > #endif > > > > /* Change the file mode mask */ > umask(0); > > #ifdef DAEMONIZE > > /* Create a new SID for the child process */ > sid = setsid(); > if (sid < 0) { > /* Log the failure */ > exit(EXIT_FAILURE); > } > #endif > > > > > /* Change the current working directory */ > if ((chdir("/")) < 0) { > /* Log the failure */ > exit(EXIT_FAILURE); > } > > /* Close out the standard file descriptors */ > close(STDIN_FILENO); > close(STDOUT_FILENO); > close(STDERR_FILENO); > > /* Daemon-specific initialization goes here */ > > /* The Big Loop */ > while (1) { > /* Do some task here ... */ > > usleep(100000); /* wait 100 milliseconds */ > } > exit(EXIT_SUCCESS); > } > > > Nothing fancy. When I build the system, the daemon gets created properly, > and lives in /system/bin, as expected. When I boot the system, however, > /init continually starts my daemon, many times, until the system eventually > runs out of memory! > > Is there something my daemon needs to do so /init doesn't think it has > died and needs to restart? > > Well, as I wrote this originally, I had an "Aha!" moment - /init must be > acting on the exit of the parent process! That would explain why it starts > another instance, even though the prior one is still around. So I got rid > of the code with the DAEMONIZE conditionals, but that just hangs the system > immediately after print this message: > > Freeing init memory: 248K > > > So, what is the proper way to write a Linux daemon that /init can manage > for me? Any ideas welcome! > > Thanks! > -- -- unsubscribe: android-porting+unsubscr...@googlegroups.com website: http://groups.google.com/group/android-porting --- You received this message because you are subscribed to the Google Groups "android-porting" group. To unsubscribe from this group and stop receiving emails from it, send an email to android-porting+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
