ssize_t lttng_ust_read(int fd, void *buf, size_t len);
size_t lttng_ust_dummy_get_size(struct lttng_ctx_field *field, size_t offset);
ssize_t lttng_ust_read(int fd, void *buf, size_t len);
size_t lttng_ust_dummy_get_size(struct lttng_ctx_field *field, size_t offset);