@@ -337,11 +337,11 @@ struct MigrationState {
*/
QemuSemaphore rp_sem;
/*
- * We post to this when we got one PONG from dest. So far it's an
+ * We set this when we got one PONG from dest. So far it's an
* easy way to know the main channel has successfully established
* on dest QEMU.
*/
- QemuSemaphore rp_pong_acks;
+ QemuEvent rp_pong_acks;
} rp_state;
double mbps;
@@ -377,7 +377,7 @@ struct MigrationState {
QemuSemaphore wait_unplug_sem;
/* Migration is paused due to pause-before-switchover */
- QemuSemaphore pause_sem;
+ QemuEvent pause_event;
/* The semaphore is used to notify COLO thread that failover is finished */
QemuSemaphore colo_exit_sem;
@@ -1522,7 +1522,7 @@ static void migrate_fd_cancel(MigrationState *s)
}
/* If the migration is paused, kick it out of the pause */
if (old_state == MIGRATION_STATUS_PRE_SWITCHOVER) {
- qemu_sem_post(&s->pause_sem);
+ qemu_event_set(&s->pause_event);
}
migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING);
} while (s->state != MIGRATION_STATUS_CANCELLING);
@@ -2135,7 +2135,7 @@ void qmp_migrate_continue(MigrationStatus state, Error **errp)
MigrationStatus_str(s->state));
return;
}
- qemu_sem_post(&s->pause_sem);
+ qemu_event_set(&s->pause_event);
}
int migration_rp_wait(MigrationState *s)
@@ -2343,7 +2343,7 @@ static void *source_return_path_thread(void *opaque)
case MIG_RP_MSG_PONG:
tmp32 = ldl_be_p(buf);
trace_source_return_path_thread_pong(tmp32);
- qemu_sem_post(&ms->rp_state.rp_pong_acks);
+ qemu_event_set(&ms->rp_state.rp_pong_acks);
break;
case MIG_RP_MSG_REQ_PAGES:
@@ -2486,7 +2486,7 @@ static inline void
migration_wait_main_channel(MigrationState *ms)
{
/* Wait until one PONG message received */
- qemu_sem_wait(&ms->rp_state.rp_pong_acks);
+ qemu_event_wait(&ms->rp_state.rp_pong_acks);
}
/*
@@ -2686,27 +2686,24 @@ static int migration_maybe_pause(MigrationState *s,
return 0;
}
- /* Since leaving this state is not atomic with posting the semaphore
+ /*
+ * Since leaving this state is not atomic with setting the event
* it's possible that someone could have issued multiple migrate_continue
- * and the semaphore is incorrectly positive at this point;
- * the docs say it's undefined to reinit a semaphore that's already
- * init'd, so use timedwait to eat up any existing posts.
+ * and the event is incorrectly set at this point so reset it.
*/
- while (qemu_sem_timedwait(&s->pause_sem, 1) == 0) {
- /* This block intentionally left blank */
- }
+ qemu_event_reset(&s->pause_event);
/*
* If the migration is cancelled when it is in the completion phase,
* the migration state is set to MIGRATION_STATUS_CANCELLING.
- * So we don't need to wait a semaphore, otherwise we would always
- * wait for the 'pause_sem' semaphore.
+ * So we don't need to wait an event, otherwise we would always
+ * wait for the 'pause_event' event.
*/
if (s->state != MIGRATION_STATUS_CANCELLING) {
bql_unlock();
migrate_set_state(&s->state, *current_active_state,
MIGRATION_STATUS_PRE_SWITCHOVER);
- qemu_sem_wait(&s->pause_sem);
+ qemu_event_wait(&s->pause_event);
migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER,
new_state);
*current_active_state = new_state;
@@ -3833,10 +3830,10 @@ static void migration_instance_finalize(Object *obj)
qemu_mutex_destroy(&ms->qemu_file_lock);
qemu_sem_destroy(&ms->wait_unplug_sem);
qemu_sem_destroy(&ms->rate_limit_sem);
- qemu_sem_destroy(&ms->pause_sem);
+ qemu_event_destroy(&ms->pause_event);
qemu_sem_destroy(&ms->postcopy_pause_sem);
qemu_sem_destroy(&ms->rp_state.rp_sem);
- qemu_sem_destroy(&ms->rp_state.rp_pong_acks);
+ qemu_event_destroy(&ms->rp_state.rp_pong_acks);
qemu_sem_destroy(&ms->postcopy_qemufile_src_sem);
error_free(ms->error);
}
@@ -3848,14 +3845,14 @@ static void migration_instance_init(Object *obj)
ms->state = MIGRATION_STATUS_NONE;
ms->mbps = -1;
ms->pages_per_second = -1;
- qemu_sem_init(&ms->pause_sem, 0);
+ qemu_event_init(&ms->pause_event, false);
qemu_mutex_init(&ms->error_mutex);
migrate_params_init(&ms->parameters);
qemu_sem_init(&ms->postcopy_pause_sem, 0);
qemu_sem_init(&ms->rp_state.rp_sem, 0);
- qemu_sem_init(&ms->rp_state.rp_pong_acks, 0);
+ qemu_event_init(&ms->rp_state.rp_pong_acks, false);
qemu_sem_init(&ms->rate_limit_sem, 0);
qemu_sem_init(&ms->wait_unplug_sem, 0);
qemu_sem_init(&ms->postcopy_qemufile_src_sem, 0);
rp_pong_acks tells if it has ever received one pong. QemuEvent is better suited for this usage because it represents a boolean rather than integer and will not decrement with the wait operation. pause_event can utilize qemu_event_reset() to discard events. Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> --- migration/migration.h | 6 +++--- migration/migration.c | 33 +++++++++++++++------------------ 2 files changed, 18 insertions(+), 21 deletions(-)