diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/qemu-timer.c | 65 |
1 files changed, 52 insertions, 13 deletions
diff --git a/util/qemu-timer.c b/util/qemu-timer.c index eb60d8f73a..1cc1b2f2c3 100644 --- a/util/qemu-timer.c +++ b/util/qemu-timer.c @@ -339,14 +339,19 @@ int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout) } -void timer_init_tl(QEMUTimer *ts, - QEMUTimerList *timer_list, int scale, - QEMUTimerCB *cb, void *opaque) +void timer_init_full(QEMUTimer *ts, + QEMUTimerListGroup *timer_list_group, QEMUClockType type, + int scale, int attributes, + QEMUTimerCB *cb, void *opaque) { - ts->timer_list = timer_list; + if (!timer_list_group) { + timer_list_group = &main_loop_tlg; + } + ts->timer_list = timer_list_group->tl[type]; ts->cb = cb; ts->opaque = opaque; ts->scale = scale; + ts->attributes = attributes; ts->expire_time = -1; } @@ -484,6 +489,7 @@ bool timerlist_run_timers(QEMUTimerList *timer_list) bool progress = false; QEMUTimerCB *cb; void *opaque; + bool need_replay_checkpoint = false; if (!atomic_read(&timer_list->active_timers)) { return false; @@ -496,12 +502,18 @@ bool timerlist_run_timers(QEMUTimerList *timer_list) switch (timer_list->clock->type) { case QEMU_CLOCK_REALTIME: - case QEMU_CLOCK_VIRTUAL_EXT: break; default: case QEMU_CLOCK_VIRTUAL: - if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL)) { - goto out; + if (replay_mode != REPLAY_MODE_NONE) { + /* Checkpoint for virtual clock is redundant in cases where + * it's being triggered with only non-EXTERNAL timers, because + * these timers don't change guest state directly. + * Since it has conditional dependence on specific timers, it is + * subject to race conditions and requires special handling. + * See below. + */ + need_replay_checkpoint = true; } break; case QEMU_CLOCK_HOST: @@ -516,14 +528,39 @@ bool timerlist_run_timers(QEMUTimerList *timer_list) break; } + /* + * Extract expired timers from active timers list and and process them. + * + * In rr mode we need "filtered" checkpointing for virtual clock. The + * checkpoint must be recorded/replayed before processing any non-EXTERNAL timer, + * and that must only be done once since the clock value stays the same. Because + * non-EXTERNAL timers may appear in the timers list while it being processed, + * the checkpoint can be issued at a time until no timers are left and we are + * done". + */ current_time = qemu_clock_get_ns(timer_list->clock->type); - for(;;) { - qemu_mutex_lock(&timer_list->active_timers_lock); - ts = timer_list->active_timers; + qemu_mutex_lock(&timer_list->active_timers_lock); + while ((ts = timer_list->active_timers)) { if (!timer_expired_ns(ts, current_time)) { - qemu_mutex_unlock(&timer_list->active_timers_lock); + /* No expired timers left. The checkpoint can be skipped + * if no timers fired or they were all external. + */ break; } + if (need_replay_checkpoint + && !(ts->attributes & QEMU_TIMER_ATTR_EXTERNAL)) { + /* once we got here, checkpoint clock only once */ + need_replay_checkpoint = false; + qemu_mutex_unlock(&timer_list->active_timers_lock); + if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL)) { + goto out; + } + qemu_mutex_lock(&timer_list->active_timers_lock); + /* The lock was released; start over again in case the list was + * modified. + */ + continue; + } /* remove timer from the list before calling the callback */ timer_list->active_timers = ts->next; @@ -531,12 +568,15 @@ bool timerlist_run_timers(QEMUTimerList *timer_list) ts->expire_time = -1; cb = ts->cb; opaque = ts->opaque; - qemu_mutex_unlock(&timer_list->active_timers_lock); /* run the callback (the timer list can be modified) */ + qemu_mutex_unlock(&timer_list->active_timers_lock); cb(opaque); + qemu_mutex_lock(&timer_list->active_timers_lock); + progress = true; } + qemu_mutex_unlock(&timer_list->active_timers_lock); out: qemu_event_set(&timer_list->timers_done_ev); @@ -598,7 +638,6 @@ int64_t qemu_clock_get_ns(QEMUClockType type) return get_clock(); default: case QEMU_CLOCK_VIRTUAL: - case QEMU_CLOCK_VIRTUAL_EXT: if (use_icount) { return cpu_get_icount(); } else { |