Summary
Queue a packet to a port.
Declaration
#include <zircon/syscalls.h>
#include <zircon/syscalls/port.h>
zx_status_t zx_port_queue(zx_handle_t handle, const zx_port_packet_t* packet);
Description
zx_port_queue() queues a user packet to the port specified by handle.
User packets are drained by zx_port_wait(). Failure to drain packets in a
timely fashion can cause excessive kernel memory to be used, which might generate
an exception. See ipc limits for details.
typedef struct zx_port_packet {
    uint64_t key;
    uint32_t type;
    zx_status_t status;
    union {
        zx_packet_user_t user;
        zx_packet_signal_t signal;
    };
} zx_port_packet_t;
In packet type should be ZX_PKT_TYPE_USER and only the user
union element is considered valid:
typedef union zx_packet_user {
    uint64_t u64[4];
    uint32_t u32[8];
    uint16_t u16[16];
    uint8_t   c8[32];
} zx_packet_user_t;
Rights
handle must be of type ZX_OBJ_TYPE_PORT and have ZX_RIGHT_WRITE.
Return value
zx_port_queue() returns ZX_OK on successful queue of a packet.
Errors
ZX_ERR_BAD_HANDLE handle isn't a valid handle
ZX_ERR_INVALID_ARGS packet is an invalid pointer.
ZX_ERR_WRONG_TYPE handle is not a port handle.
ZX_ERR_ACCESS_DENIED handle does not have ZX_RIGHT_WRITE.