io_read_t

Структура, характеризующая сообщения менеджера ресурсов типа _IO_READ

Прототип:

#include <sys/iofunc.h>
struct _io_read {
uint16_t type;
uint16_t combine_len;
int32_t nbytes;
uint32_t xtype;
uint32_t zero;
};
typedef union {
struct _io_read i;
/* unsigned char data[nbytes]; */
/* nbytes is returned with MsgReply */
} io_read_t;

Описание:

Данная структура ассоциирована с сообщениями менеджера ресурсов типа _IO_READ. Поле i определяет входящие данные (поступающие в менеджер ресурсов).

The i member is a structure of type _io_read that contains the following members:

type
_IO_READ.
combine_len
If the message is a combine message, _IO_COMBINE_FLAG is set in this member.
nbytes
The number of bytes that the client wants to read.
xtype
Extended type information; one of:
_IO_XTYPE_NONE
_IO_XTYPE_READCOND
_IO_XTYPE_MQUEUE
_IO_XTYPE_TCPIP
_IO_XTYPE_TCPIP_MSG
_IO_XTYPE_OFFSET
_IO_XTYPE_REGISTRY
_IO_XFLAG_DIR_EXTRA_HINT
this flag is valid only when reading from a directory. The filesystem should normally return extra directory information when it's easy to get. If this flag is set, it is a hint to the filesystem to try harder (possibly causing media lookups) to return the extra information. The most common use would be to return _DTYPE_LSTAT information.
_IO_XFLAG_NONBLOCK
_IO_XFLAG_BLOCK

The commented-out declaration for data indicates that nbytes bytes of data immediately follow the io_read_t structure.

Классификация:

ЗОСРВ «Нейтрино»

Тематические ссылки:

resmgr_io_funcs_t, iofunc_read_default(), iofunc_read_verify()




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