+ struct {
+ uint64_t subbuf_size; /* bytes */
+ uint64_t num_subbuf; /* power of 2 */
+ int overwrite; /* 1: overwrite, 0: discard */
+ unsigned int switch_timer_interval; /* usec */
+ unsigned int read_timer_interval; /* usec */
+ int output; /* splice, mmap */
+ int type; /* metadata or per_cpu */
+ uint64_t session_id; /* Tracing session id */
+ char pathname[PATH_MAX]; /* Channel file path. */
+ char name[LTTNG_SYMBOL_NAME_LEN]; /* Channel name. */
+ uid_t uid; /* User ID of the session */
+ gid_t gid; /* Group ID ot the session */
+ int relayd_id; /* Relayd id if apply. */
+ unsigned long key; /* Unique channel key. */
+ unsigned char uuid[UUID_STR_LEN]; /* uuid for ust tracer. */
+ } LTTNG_PACKED ask_channel;
+ struct {
+ unsigned long key;
+ } LTTNG_PACKED get_channel;
+ struct {
+ unsigned long key;
+ } LTTNG_PACKED destroy_channel;