static int os_host_main_loop_wait(int64_t timeout)
{
int ret;
static int spin_counter;
glib_pollfds_fill(&timeout);
/* If the I/O thread is very busy or we are incorrectly busy waiting in
* the I/O thread, this can lead to starvation of the BQL such that the
* VCPU threads never run. To make sure we can detect the later case,
* print a message to the screen. If we run into this condition, create
* a fake timeout in order to give the VCPU threads a chance to run.
*/
if (!timeout && (spin_counter > MAX_MAIN_LOOP_SPIN)) {
static bool notified;
if (!notified) {
fprintf(stderr,
"main-loop: WARNING: I/O thread spun for %d iterations\n",
MAX_MAIN_LOOP_SPIN);
notified = true;
}
timeout = SCALE_MS;
}
if (timeout) {
spin_counter = 0;
qemu_mutex_unlock_iothread();
} else {
spin_counter++;
}
ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
if (timeout) {
qemu_mutex_lock_iothread();
}
glib_pollfds_poll();
return ret;
}
static int os_host_main_loop_wait(int64_t timeout)
{
GMainContext *context = g_main_context_default();
int ret;
g_main_context_acquire(context);
glib_pollfds_fill(&timeout);
qemu_mutex_unlock_iothread();
replay_mutex_unlock();
ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
replay_mutex_lock();
qemu_mutex_lock_iothread();
glib_pollfds_poll();
g_main_context_release(context);
return ret;
}
