Commit d32749deb615 moved the call to monitor_init_globals() to before os_daemonize(), making it an unsuitable place to spawn the monitor iothread as it won't be inherited over the fork() in os_daemonize().
We now spawn the thread the first time we instantiate a monitor which actually has use_io_thread == true. Instantiation of monitors happens only after os_daemonize(). We still need to create the qmp_dispatcher_bh when not using iothreads, so this now still happens in monitor_init_globals(). Signed-off-by: Wolfgang Bumiller <[email protected]> Fixes: d32749deb615 ("monitor: move init global earlier") --- monitor.c | 38 +++++++++++++++++++++++--------------- 1 file changed, 23 insertions(+), 15 deletions(-) diff --git a/monitor.c b/monitor.c index 4802148c82..e9d44b443b 100644 --- a/monitor.c +++ b/monitor.c @@ -806,9 +806,14 @@ static void monitor_qapi_event_init(void) static void handle_hmp_command(Monitor *mon, const char *cmdline); +static void monitor_iothread_init(void); + static void monitor_data_init(Monitor *mon, bool skip_flush, bool use_io_thread) { + if (use_io_thread && !mon_iothread) { + monitor_iothread_init(); + } memset(mon, 0, sizeof(Monitor)); qemu_mutex_init(&mon->mon_lock); qemu_mutex_init(&mon->qmp.qmp_queue_lock); @@ -4551,15 +4556,6 @@ static void monitor_iothread_init(void) mon_iothread = iothread_create("mon_iothread", &error_abort); /* - * The dispatcher BH must run in the main loop thread, since we - * have commands assuming that context. It would be nice to get - * rid of those assumptions. - */ - qmp_dispatcher_bh = aio_bh_new(iohandler_get_aio_context(), - monitor_qmp_bh_dispatcher, - NULL); - - /* * The responder BH must be run in the monitor I/O thread, so that * monitors that are using the I/O thread have their output * written by the I/O thread. @@ -4576,7 +4572,15 @@ void monitor_init_globals(void) sortcmdlist(); qemu_mutex_init(&monitor_lock); qemu_mutex_init(&mon_fdsets_lock); - monitor_iothread_init(); + + /* + * The dispatcher BH must run in the main loop thread, since we + * have commands assuming that context. It would be nice to get + * rid of those assumptions. + */ + qmp_dispatcher_bh = aio_bh_new(iohandler_get_aio_context(), + monitor_qmp_bh_dispatcher, + NULL); } /* These functions just adapt the readline interface in a typesafe way. We @@ -4717,7 +4721,9 @@ void monitor_cleanup(void) * we need to unregister from chardev below in * monitor_data_destroy(), and chardev is not thread-safe yet */ - iothread_stop(mon_iothread); + if (mon_iothread) { + iothread_stop(mon_iothread); + } /* * Flush all response queues. Note that even after this flush, @@ -4738,11 +4744,13 @@ void monitor_cleanup(void) /* QEMUBHs needs to be deleted before destroying the I/O thread */ qemu_bh_delete(qmp_dispatcher_bh); qmp_dispatcher_bh = NULL; - qemu_bh_delete(qmp_respond_bh); - qmp_respond_bh = NULL; + if (mon_iothread) { + qemu_bh_delete(qmp_respond_bh); + qmp_respond_bh = NULL; - iothread_destroy(mon_iothread); - mon_iothread = NULL; + iothread_destroy(mon_iothread); + mon_iothread = NULL; + } } QemuOptsList qemu_mon_opts = { -- 2.11.0
