zx_fifo_write

Summary

Write data to a fifo.

Declaration

#include <zircon/syscalls.h>

zx_status_t zx_fifo_write(zx_handle_t handle,
                          size_t elem_size,
                          const void* data,
                          size_t count,
                          size_t* actual_count);

Description

zx_fifo_write() attempts to write up to count elements (count * elem_size bytes) from data 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 zx_fifo_create().

actual_count is allowed to be NULL. This is useful when writing a single element: if count is 1 and zx_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.

Rights

handle must be of type ZX_OBJ_TYPE_FIFO and have ZX_RIGHT_WRITE.

Return value

zx_fifo_write() returns ZX_OK on success, and returns the number of elements written (at least one) via actual_count.

Errors

ZX_ERR_BAD_HANDLE handle is not a valid handle.

ZX_ERR_WRONG_TYPE handle is not a fifo handle.

ZX_ERR_INVALID_ARGS data 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.

See also