Re: [RFC PATCH 09/18] qemu-storage-daemon: Add main loop

[Markus Armbruster]

Kevin Wolf <address@hidden> writes:

> Instead of exiting after processing all command line options, start a
> main loop and keep processing events until exit is requested with a
> signal (e.g. SIGINT).
>
> Now qemu-storage-daemon can be used as an alternative for qemu-nbd that
> provides a few features that were previously only available from QMP,
> such as access to options only available with -blockdev and the socket
> types 'vsock' and 'fd'.
>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>  qemu-storage-daemon.c | 13 +++++++++++++
>  Makefile.objs         |  2 ++
>  2 files changed, 15 insertions(+)
>
> diff --git a/qemu-storage-daemon.c b/qemu-storage-daemon.c
> index 9e5f474fd0..099388f645 100644
> --- a/qemu-storage-daemon.c
> +++ b/qemu-storage-daemon.c
> @@ -45,10 +45,18 @@
>  #include "qemu/option.h"
>  #include "qom/object_interfaces.h"
>  
> +#include "sysemu/runstate.h"
>  #include "trace/control.h"
>  
>  #include <getopt.h>
>  
> +static bool exit_requested = false;
> +
> +void qemu_system_killed(int signal, pid_t pid)
> +{
> +    exit_requested = true;
> +}
> +

This runs within a signal handler, so better make @exit_requested
volatile.  Hmm, vl.c gets it wrong, too.

>  static void help(void)
>  {
>      printf(
> @@ -238,6 +246,7 @@ int main(int argc, char *argv[])
>  
>      error_init(argv[0]);
>      qemu_init_exec_dir(argv[0]);
> +    os_setup_signal_handling();
>  
>      module_call_init(MODULE_INIT_QOM);
>      module_call_init(MODULE_INIT_TRACE);
> @@ -256,5 +265,9 @@ int main(int argc, char *argv[])
>          return EXIT_FAILURE;
>      }
>  
> +    while (!exit_requested) {
> +        main_loop_wait(false);
> +    }
> +
>      return EXIT_SUCCESS;
>  }
> diff --git a/Makefile.objs b/Makefile.objs
> index cc262e445f..b667d3f07b 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -43,6 +43,8 @@ io-obj-y = io/
>  
>  storage-daemon-obj-y = block/
>  storage-daemon-obj-y += blockdev.o blockdev-nbd.o iothread.o
> +storage-daemon-obj-$(CONFIG_WIN32) += os-win32.o
> +storage-daemon-obj-$(CONFIG_POSIX) += os-posix.o
>  
>  ######################################################################
>  # Target independent part of system emulation. The long term path is to