io_mmap_t

Структура, характеризующая сообщения менеджера ресурсов типа _IO_MMAP

Прототип:

#include <sys/iofunc.h>
struct _io_mmap {
uint16_t type;
uint16_t combine_len;
uint32_t prot;
uint64_t offset;
struct _msg_info info;
uint32_t zero[6];
};
struct _io_mmap_reply {
uint32_t zero;
uint32_t flags;
uint64_t offset;
int32_t coid;
int32_t fd;
};
typedef union {
struct _io_mmap i;
struct _io_mmap_reply o;
} io_mmap_t;

Описание:

Данная структура ассоциирована с сообщениями менеджера ресурсов типа _IO_MMAP. Поле i определяет входящие данные (поступающие в менеджер ресурсов), поле o исходящие (отправляемые обратно клиенту).

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

type
_IO_MMAP
combine_len
If the message is a combine message, _IO_COMBINE_FLAG is set in this member.
prot
The access capabilities that the client wants to use for the memory region being mapped. This can be a combination of at least the following protection bits, as defined in <sys/mman.h>:
PROT_EXEC
the region can be executed.
PROT_NOCACHE
disable caching of the region (e.g. so it can be used to access dual-ported memory).
PROT_NONE
the region can't be accessed.
PROT_READ
the region can be read.
PROT_WRITE
the region can be written.
offset
The offset into shared memory of the location that the client wants to start mapping.
info
A pointer to a struct _msg_info, that contains information about the message received by the resource manager.

The o member of the io_mmap_t structure is a structure of type _io_mmap_reply that contains the following members:

flags
Reserved for future use.
offset
Reserved for future use.
coid
A file descriptor that the process manager can use to access the mapped file.
fd
Reserved for future use.

Классификация:

ЗОСРВ «Нейтрино»

Тематические ссылки:

resmgr_io_funcs_t, iofunc_mmap_default(), iofunc_mmap()




Предыдущий раздел: Описание API системной библиотеки