Signal an object's peer.
#include <zircon/syscalls.h> zx_status_t zx_object_signal_peer(zx_handle_t handle, uint32_t clear_mask, uint32_t set_mask);
zx_object_signal_peer() asserts and deasserts the userspace-accessible signal bits on the object's peer. A object peer is the opposite endpoint of a channel, socket, fifo, or eventpair.
Most of the 32 signals are reserved for system use and are assigned to per-object functions, like ZX_CHANNEL_READABLE or ZX_TASK_TERMINATED. There are 8 signal bits available for userspace processes to use as they see fit: ZX_USER_SIGNAL_0 through ZX_USER_SIGNAL_7.
Eventpair objects also allow control over the ZX_EVENTPAIR_SIGNALED bit.
The clear_mask is first used to clear any bits indicated, and then the set_mask is used to set any bits indicated.
handle must have ZX_RIGHT_SIGNAL_PEER.
zx_object_signal_peer() returns ZX_OK on success. In the event of failure, a negative error value is returned.
ZX_ERR_BAD_HANDLE handle is not a valid handle.
ZX_ERR_ACCESS_DENIED handle lacks the right ZX_RIGHT_SIGNAL_PEER.
ZX_ERR_INVALID_ARGS clear_mask or set_mask contain bits that are not allowed.
ZX_ERR_NOT_SUPPORTED Used on an object lacking a peer.
ZX_ERR_PEER_CLOSED Called on an object with a closed peer.