fifo_write - write data to a fifo
#include <zircon/syscalls.h>
zx_status_t zx_fifo_write(zx_handle_t handle, size_t elem_size,
const void* buffer, size_t count, size_t* actual_count);
fifo_write() attempts to write up to count elements (count * elem_size bytes) from buf to the fifo specified by handle.
Fewer elements may be written than requested if there is insufficient room in the fifo to contain all of them. The number of elements actually written is returned via actual_count.
The element size specified by elem_size must match the element size that was passed into fifo_create().
actual_count is allowed to be NULL. This is useful when writing a single element: if count is 1 and fifo_write() returns ZX_OK, actual_count is guaranteed to be 1 and thus can be safely ignored.
It is not legal to write zero elements.
handle must have ZX_RIGHT_WRITE.
fifo_write() returns ZX_OK on success, and returns the number of elements written (at least one) via actual_count.
ZX_ERR_BAD_HANDLE handle is not a valid handle.
ZX_ERR_WRONG_TYPE handle is not a fifo handle.
ZX_ERR_INVALID_ARGS buffer is an invalid pointer or actual_count is an invalid pointer.
ZX_ERR_OUT_OF_RANGE count is zero or elem_size is not equal to the element size of the fifo.
ZX_ERR_ACCESS_DENIED handle does not have ZX_RIGHT_WRITE.
ZX_ERR_PEER_CLOSED The other side of the fifo is closed.
ZX_ERR_SHOULD_WAIT The fifo is full.