zx_vmo_read

NAME

vmo_read - read bytes from the VMO

SYNOPSIS

#include <zircon/syscalls.h>

zx_status_t zx_vmo_read(zx_handle_t handle, void* data, uint64_t offset, size_t len);

DESCRIPTION

vmo_read() attempts to read exactly len bytes from a VMO at offset.

data pointer to a user buffer to read bytes into.

len number of bytes to attempt to read. data buffer should be large enough for at least this many bytes.

RETURN VALUE

zx_vmo_read() returns ZX_OK on success, and exactly len bytes will have been written to data. In the event of failure, a negative error value is returned, and the number of bytes written to data is undefined.

ERRORS

ZX_ERR_BAD_HANDLE handle is not a valid handle.

ZX_ERR_WRONG_TYPE handle is not a VMO handle.

ZX_ERR_ACCESS_DENIED handle does not have the ZX_RIGHT_READ right.

ZX_ERR_INVALID_ARGS data is an invalid pointer or NULL.

ZX_ERR_OUT_OF_RANGE offset starts at or beyond the end of the VMO, or VMO is shorter than len.

ZX_ERR_BAD_STATE VMO has been marked uncached and is not directly readable.

SEE ALSO

vmo_create, vmo_clone, vmo_write, vmo_get_size, vmo_set_size, vmo_op_range. vmo_set_cache_policy