readahead

Autres langues

Langue: ja

Autres versions - même langue

Version: 2004-10-05 (openSuse - 09/10/07)

Autres sections - même nom

Section: 2 (Appels système)

Sommaire

̾Á°

readahead - Á°¤â¤Ã¤Æ¥Õ¥¡¥¤¥ë¤ò¥Ú¡¼¥¸¡¦¥­¥ã¥Ã¥·¥å¤ËÆɤ߹þ¤à

½ñ¼°


#include <fcntl.h>



ssize_t readahead(int fd, off64_t *offset, size_t count);

ÀâÌÀ

readahead() ¤Ï¡¢¤³¤Î¸å¤ÎƱ¤¸¥Õ¥¡¥¤¥ë¤«¤é¤Î¥Ç¡¼¥¿Æɤ߹þ¤ß»þ¤Ë¥Ç¥£¥¹¥¯ I/O ¤Ç Æ°ºî¤¬Ää»ß (block) ¤·¤Ê¤¤¤è¤¦¤Ë¡¢Á°¤â¤Ã¤Æ¥Õ¥¡¥¤¥ë¤ÎÆâÍƤò ¥Ú¡¼¥¸¡¦¥­¥ã¥Ã¥·¥å¤ËÆɤ߹þ¤à¡£ fd °ú¤­¿ô¤ÏÆɤ߹þ¤ß¤ò¹Ô¤¦¥Õ¥¡¥¤¥ë¤ò¼±Ê̤¹¤ë¥Õ¥¡¥¤¥ë¡¦¥Ç¥£¥¹¥¯¥ê¥×¥¿¤Ç¤¢¤ë¡£ offset °ú¤­¿ô¤Ï¥Ç¡¼¥¿¤ÎÆɤ߹þ¤ß³«»Ï°ÌÃÖ¤ò»ØÄꤷ¡¢ count ¤ÏÆɤ߹þ¤à¥Ç¡¼¥¿¤Î¥Ð¥¤¥È¿ô¤ò»ØÄꤹ¤ë¡£ ¥Ç¥£¥¹¥¯ I/O ¤Ï¥Ú¡¼¥¸Ã±°Ì¤Ç¼Â¹Ô¤µ¤ì¤ë¤Î¤Ç¡¢ ¼ÂºÝ¤Ë¤Ï offset ¤Ï¥Ú¡¼¥¸¶­³¦¤ËÀڤ겼¤²¤é¤ì¡¢Æɤ߹þ¤ß¥Ð¥¤¥È¿ô¤Ï (offset+count) ¤è¤ê¾®¤µ¤¯¤Ê¤¤¼¡¤Î¥Ú¡¼¥¸¶­³¦¤Þ¤ÇÀÚ¤ê¾å¤²¤é¤ì¤ë¡£ readahead() ¤Ï¥Õ¥¡¥¤¥ë¤ÎËöÈø¤ò±Û¤¨¤¿ÈϰϤޤÇÆɤ߽Ф·¤ò¹Ô¤¦¤³¤È¤Ï¤Ê¤¤¡£¤Þ¤¿¡¢ readahead() ¤Ï»ØÄꤷ¤¿¥Ç¡¼¥¿¤ÎÆɤ߹þ¤ß¤¬½ª¤ï¤ë¤Þ¤ÇÄä»ß (block) ¤¹¤ë¡£ fd ¤Ç»²¾È¤µ¤ì¤¿¥ª¡¼¥×¥óºÑ¤Î¥Õ¥¡¥¤¥ë¤Î¥Õ¥¡¥¤¥ë¥ª¥Õ¥»¥Ã¥È¤Î¸½ºßÃÍ¤Ï Êѹ¹¤µ¤ì¤Ê¤¤¡£

ÊÖ¤êÃÍ

readahead() ¤ÏÀ®¸ù¤¹¤ë¤È 0 ¤òÊÖ¤¹¡£¼ºÇÔ¤·¤¿¾ì¹ç -1 ¤òÊÖ¤·¡¢ errno ¤Ë¥¨¥é¡¼¤Î¸¶°ø¤ò¼¨¤¹ÃͤòÀßÄꤹ¤ë¡£

¥¨¥é¡¼

EBADF
fd ¤¬Í­¸ú¤Ê¥Õ¥¡¥¤¥ë¡¦¥Ç¥£¥¹¥¯¥ê¥×¥¿¤Ç¤Ê¤¤¡¢¤Þ¤¿¤Ï Æɤ߹þ¤ßÍѤ˥ª¡¼¥×¥ó¤µ¤ì¤Æ¤¤¤Ê¤¤¡£
EINVAL
fd ¤¬»²¾È¤·¤Æ¤¤¤ë¥Õ¥¡¥¤¥ë¤¬¡¢ readahead() ¤ò¹Ô¤¦¤³¤È¤¬¤Ç¤­¤Ê¤¤¥¿¥¤¥×¤Î¥Õ¥¡¥¤¥ë¤Ç¤¢¤Ã¤¿¡£

½àµò

readahead() ¥·¥¹¥Æ¥à¥³¡¼¥ë¤Ï Linux ¸ÇÍ­¤Ç¤¢¤ê¡¢°Ü¿¢¤ò¹Íθ¤·¤¿¥×¥í¥°¥é¥à¤Ç¤Ï »ÈÍѤòÈò¤±¤ë¤Ù¤­¤Ç¤¢¤ë¡£

È÷¹Í

readahead() ¥·¥¹¥Æ¥à¥³¡¼¥ë¤Ï Linux 2.4.13 ¤ÇÅо줷¤¿¡£

´ØÏ¢¹àÌÜ

fadvise(2), lseek(2), madvise(2), mmap(2), posix_fadvise(2), read(2)