vmo_write.md

mx_vmo_write

NAME

vmo_write - write bytes to the VMO

SYNOPSIS

#include <magenta/syscalls.h>

mx_status_t mx_vmo_write(mx_handle_t handle, const void* data, uint64_t offset,
                         size_t len, size_t* actual);

DESCRIPTION

vmo_write() attempts to write len bytes to a VMO at offset. The number of actual bytes written is returned in actual.

data pointer to a user buffer to write bytes from.

len number of bytes to attempt to write.

actual returns the actual number of bytes written, which may be anywhere from 0 to len. If a write extends beyond the size of the VMO, the actual bytes written will be trimmed to the end of the VMO. If the write starts at or beyond the size of the VMO, ERR_OUT_OF_RANGE will be returned.

RETURN VALUE

mx_vmo_write() returns NO_ERROR on success. In the event of failure, a negative error value is returned.

ERRORS

ERR_BAD_HANDLE handle is not a valid handle.

ERR_WRONG_TYPE handle is not a VMO handle.

ERR_INVALID_ARGS actual or data is an invalid pointer or NULL.

ERR_NO_MEMORY Failure to allocate system memory to complete write.

ERR_OUT_OF_RANGE offset starts at or beyond the end of the VMO.

SEE ALSO

vmo_create, vmo_read, vmo_get_size, vmo_set_size, vmo_op_range.