/*
* Write at most one packet in the channel.
* Returns the number of bytes written on success, < 0 on error.
*/
ssize_t ustctl_write_one_packet_to_channel(
struct ustctl_consumer_channel *channel,
const char *metadata_str, /* NOT null-terminated */
size_t len) /* metadata length */
{
struct lttng_ust_lib_ring_buffer_ctx ctx;
struct lttng_channel *chan = channel->chan;
const char *str = metadata_str;
ssize_t reserve_len;
int ret;
reserve_len = min_t(ssize_t,
chan->ops->packet_avail_size(chan->chan, chan->handle),
len);
lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
sizeof(char), -1, chan->handle);
ret = chan->ops->event_reserve(&ctx, 0);
if (ret != 0) {
DBG("LTTng: event reservation failed");
assert(ret < 0);
reserve_len = ret;
goto end;
}
chan->ops->event_write(&ctx, str, reserve_len);
chan->ops->event_commit(&ctx);
end:
return reserve_len;
}
/* The probe function */
void probe(struct lttng_event* __tp_data)
{
struct lttng_event *__event = (struct lttng_event *) __tp_data;
struct lttng_channel *__chan = __event->chan;
struct lttng_ust_lib_ring_buffer_ctx __ctx;
size_t __event_len, __event_align;
int __ret;
__event_len = 0;
__event_align = 0;
lib_ring_buffer_ctx_init(&__ctx, __chan->chan, __event, __event_len,
__event_align, -1, __chan->handle);
__ctx.ip = __builtin_return_address(0);
__ret = __chan->ops->event_reserve(&__ctx, __event->id);
if (__ret < 0)
return;
__chan->ops->event_commit(&__ctx);
}
int ustctl_write_metadata_to_channel(
struct ustctl_consumer_channel *channel,
const char *metadata_str, /* NOT null-terminated */
size_t len) /* metadata length */
{
struct lttng_ust_lib_ring_buffer_ctx ctx;
struct lttng_channel *chan = channel->chan;
const char *str = metadata_str;
int ret = 0, waitret;
size_t reserve_len, pos;
for (pos = 0; pos < len; pos += reserve_len) {
reserve_len = min_t(size_t,
chan->ops->packet_avail_size(chan->chan, chan->handle),
len - pos);
lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
sizeof(char), -1, chan->handle);
/*
* We don't care about metadata buffer's records lost
* count, because we always retry here. Report error if
* we need to bail out after timeout or being
* interrupted.
*/
waitret = wait_cond_interruptible_timeout(
({
ret = chan->ops->event_reserve(&ctx, 0);
ret != -ENOBUFS || !ret;
}),
LTTNG_METADATA_TIMEOUT_MSEC);
if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) {
DBG("LTTng: Failure to write metadata to buffers (%s)\n",
waitret == -EINTR ? "interrupted" :
(ret == -ENOBUFS ? "timeout" : "I/O error"));
if (waitret == -EINTR)
ret = waitret;
goto end;
}
chan->ops->event_write(&ctx, &str[pos], reserve_len);
chan->ops->event_commit(&ctx);
}
