static int buffered_close(void *opaque)
{
QEMUFileBuffered *s = opaque;
ssize_t ret = 0;
int ret2;
DPRINTF("closing\n");
s->xfer_limit = INT_MAX;
while (!qemu_file_get_error(s->file) && s->buffer_size) {
ret = buffered_flush(s);
if (ret < 0) {
break;
}
if (s->freeze_output) {
ret = migrate_fd_wait_for_unfreeze(s->migration_state);
if (ret < 0) {
break;
}
}
}
ret2 = migrate_fd_close(s->migration_state);
if (ret >= 0) {
ret = ret2;
}
qemu_del_timer(s->timer);
qemu_free_timer(s->timer);
g_free(s->buffer);
g_free(s);
return ret;
}
static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
{
QEMUFileBuffered *s = opaque;
int offset = 0, error;
ssize_t ret;
DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos);
error = qemu_file_get_error(s->file);
if (error) {
DPRINTF("flush when error, bailing: %s\n", strerror(-error));
return error;
}
DPRINTF("unfreezing output\n");
s->freeze_output = 0;
buffered_flush(s);
while (!s->freeze_output && offset < size) {
if (s->bytes_xfer > s->xfer_limit) {
DPRINTF("transfer limit exceeded when putting\n");
break;
}
ret = s->put_buffer(s->opaque, buf + offset, size - offset);
if (ret == -EAGAIN) {
DPRINTF("backend not ready, freezing\n");
s->freeze_output = 1;
break;
}
if (ret <= 0) {
DPRINTF("error putting\n");
qemu_file_set_error(s->file, ret);
offset = -EINVAL;
break;
}
DPRINTF("put %zd byte(s)\n", ret);
offset += ret;
s->bytes_xfer += ret;
}
if (offset >= 0) {
DPRINTF("buffering %d bytes\n", size - offset);
buffered_append(s, buf + offset, size - offset);
offset = size;
}
if (pos == 0 && size == 0) {
DPRINTF("file is ready\n");
if (s->bytes_xfer <= s->xfer_limit) {
DPRINTF("notifying client\n");
s->put_ready(s->opaque);
}
}
return offset;
}
static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
{
QEMUFileBuffered *s = opaque;
int offset = 0;
ssize_t ret;
DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos);
if (s->has_error) {
DPRINTF("flush when error, bailing\n");
return -EINVAL;
}
DPRINTF("unfreezing output\n");
s->freeze_output = 0;
buffered_flush(s);
while (!s->freeze_output && offset < size) {
if (s->bytes_xfer > s->xfer_limit) {
DPRINTF("transfer limit exceeded when putting\n");
break;
}
ret = s->put_buffer(s->opaque, buf + offset, size - offset);
if (ret == -EAGAIN) {
DPRINTF("backend not ready, freezing\n");
s->freeze_output = 1;
break;
}
if (ret <= 0) {
DPRINTF("error putting\n");
s->has_error = 1;
offset = -EINVAL;
break;
}
DPRINTF("put %zd byte(s)\n", ret);
offset += ret;
s->bytes_xfer += ret;
}
if (offset >= 0) {
DPRINTF("buffering %d bytes\n", size - offset);
buffered_append(s, buf + offset, size - offset);
offset = size;
}
return offset;
}
QEMUFile *qemu_fopen_ops_buffered(void *opaque,
size_t bytes_per_sec,
BufferedPutFunc *put_buffer,
BufferedPutReadyFunc *put_ready,
BufferedWaitForUnfreezeFunc *wait_for_unfreeze,
BufferedCloseFunc *close)
{
// dummy functions & dummy calls
buffered_append(NULL, NULL, 0);
buffered_flush(NULL);
buffered_put_buffer(opaque, NULL, 0, 0);
buffered_close(opaque);
buffered_rate_limit(opaque);
buffered_set_rate_limit(opaque, 0);
buffered_get_rate_limit(opaque);
buffered_rate_tick(opaque);
return NULL;
}
static void buffered_rate_tick(void *opaque)
{
QEMUFileBuffered *s = opaque;
if (s->has_error)
return;
qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 100);
if (s->freeze_output)
return;
s->bytes_xfer = 0;
buffered_flush(s);
/* Add some checks around this */
s->put_ready(s->opaque);
}
static int buffered_close(void *opaque)
{
QEMUFileBuffered *s = opaque;
int ret;
DPRINTF("closing\n");
while (!s->has_error && s->buffer_size) {
buffered_flush(s);
if (s->freeze_output)
s->wait_for_unfreeze(s);
}
ret = s->close(s->opaque);
qemu_del_timer(s->timer);
qemu_free_timer(s->timer);
qemu_free(s->buffer);
qemu_free(s);
return ret;
}
static int buffered_close(void *opaque)
{
MigrationState *s = opaque;
ssize_t ret = 0;
int ret2;
DPRINTF("closing\n");
s->xfer_limit = INT_MAX;
while (!qemu_file_get_error(s->file) && s->buffer_size) {
ret = buffered_flush(s);
if (ret < 0) {
break;
}
}
ret2 = migrate_fd_close(s);
if (ret >= 0) {
ret = ret2;
}
s->complete = true;
return ret;
}
static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
{
QEMUFileBuffered *s = opaque;
ssize_t error;
DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos);
error = qemu_file_get_error(s->file);
if (error) {
DPRINTF("flush when error, bailing: %s\n", strerror(-error));
return error;
}
DPRINTF("unfreezing output\n");
s->freeze_output = 0;
if (size > 0) {
DPRINTF("buffering %d bytes\n", size);
buffered_append(s, buf, size);
}
error = buffered_flush(s);
if (error < 0) {
DPRINTF("buffered flush error. bailing: %s\n", strerror(-error));
return error;
}
if (pos == 0 && size == 0) {
DPRINTF("file is ready\n");
if (!s->freeze_output && s->bytes_xfer < s->xfer_limit) {
DPRINTF("notifying client\n");
migrate_fd_put_ready(s->migration_state);
}
}
return size;
}
static void *buffered_file_thread(void *opaque)
{
MigrationState *s = opaque;
int64_t initial_time = qemu_get_clock_ms(rt_clock);
int64_t max_size = 0;
bool last_round = false;
int ret;
qemu_mutex_lock_iothread();
DPRINTF("beginning savevm\n");
ret = qemu_savevm_state_begin(s->file, &s->params);
if (ret < 0) {
DPRINTF("failed, %d\n", ret);
qemu_mutex_unlock_iothread();
goto out;
}
qemu_mutex_unlock_iothread();
while (true) {
int64_t current_time = qemu_get_clock_ms(rt_clock);
uint64_t pending_size;
qemu_mutex_lock_iothread();
if (s->state != MIG_STATE_ACTIVE) {
DPRINTF("put_ready returning because of non-active state\n");
qemu_mutex_unlock_iothread();
break;
}
if (s->complete) {
qemu_mutex_unlock_iothread();
break;
}
if (s->bytes_xfer < s->xfer_limit) {
DPRINTF("iterate\n");
pending_size = qemu_savevm_state_pending(s->file, max_size);
DPRINTF("pending size %lu max %lu\n", pending_size, max_size);
if (pending_size && pending_size >= max_size) {
ret = qemu_savevm_state_iterate(s->file);
if (ret < 0) {
qemu_mutex_unlock_iothread();
break;
}
} else {
int old_vm_running = runstate_is_running();
int64_t start_time, end_time;
DPRINTF("done iterating\n");
start_time = qemu_get_clock_ms(rt_clock);
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
if (old_vm_running) {
vm_stop(RUN_STATE_FINISH_MIGRATE);
} else {
vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
}
ret = qemu_savevm_state_complete(s->file);
if (ret < 0) {
qemu_mutex_unlock_iothread();
break;
} else {
migrate_fd_completed(s);
}
end_time = qemu_get_clock_ms(rt_clock);
s->total_time = end_time - s->total_time;
s->downtime = end_time - start_time;
if (s->state != MIG_STATE_COMPLETED) {
if (old_vm_running) {
vm_start();
}
}
last_round = true;
}
}
qemu_mutex_unlock_iothread();
if (current_time >= initial_time + BUFFER_DELAY) {
uint64_t transferred_bytes = s->bytes_xfer;
uint64_t time_spent = current_time - initial_time;
double bandwidth = transferred_bytes / time_spent;
max_size = bandwidth * migrate_max_downtime() / 1000000;
DPRINTF("transferred %" PRIu64 " time_spent %" PRIu64
" bandwidth %g max_size %" PRId64 "\n",
transferred_bytes, time_spent, bandwidth, max_size);
s->bytes_xfer = 0;
initial_time = current_time;
}
if (!last_round && (s->bytes_xfer >= s->xfer_limit)) {
/* usleep expects microseconds */
g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
}
ret = buffered_flush(s);
if (ret < 0) {
break;
}
}
out:
if (ret < 0) {
migrate_fd_error(s);
}
g_free(s->buffer);
return NULL;
}
