wait_set_add - add an entry to a wait set
#include <magenta/syscalls.h>
mx_status_t mx_wait_set_add(mx_handle_t wait_set_handle,
mx_handle_t handle,
mx_signals_t signals,
uint64_t cookie);
wait_set_add() adds an entry to a wait set; an entry consists of a handle, a set of signals that the wait set will "watch", and a cookie to uniquely identify the entry. Note that there may be multiple entries with the same handle (with the same or different set of signals to watch), but that each entry must have a distinct cookie to identify it.
wait_set_handle must have the MX_RIGHT_WRITE right and handle must have the MX_RIGHT_READ write.
wait_set_add() returns NO_ERROR (which is zero) on success. On failure, a (strictly) negative error value is returned.
ERR_NO_MEMORY (Temporary) Failure due to lack of memory.
ERR_BAD_HANDLE wait_set_handle is not a valid handle.
ERR_INVALID_ARGS wait_set_handle is not a handle to a wait set or handle is not a valid handle.
ERR_ACCESS_DENIED wait_set_handle does not have the MX_RIGHT_WRITE right or handle does not have the MX_RIGHT_READ right.
ERR_NOT_SUPPORTED handle does not refer to a waitable object.
ERR_ALREADY_EXISTS The wait set already has an entry with the same cookie as cookie.
wait_set_create, wait_set_remove, wait_set_wait, handle_close.