LOCKFILE

NAME
SYNOPSIS æ»è§
DESCRIPTION æè¿°
RETURN VALUE è¿åå¼
ERRORS
AVAILABILITY
CONFORMING TO æ ååè
SEE ALSO åè§
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NAME

flockfile, ftrylockfile, funlockfile - 为æ åè¾å¥è¾åºéå®æ件 FILE

SYNOPSIS æ»è§

#include <stdio.h>

void flockfile(FILE *filehandle);
int ftrylockfile(FILE *filehandle);
void funlockfile(FILE *filehandle);

DESCRIPTION æè¿°

æ åè¾å¥è¾åºåº stdio å½æ°æ¯çº¿ç¨å®å¨çãè¿æ¯éè¿ä¸ºæ¯ä¸ªæ件对象 FILE èµäºä¸ä¸ªéå®è®¡æ°å (å½éå®è®¡æ°éé¶æ¶) ä¸ä¸ªææè线ç¨æ¥å®ç°çã对æ¯ä¸ªåºå½æ°è°ç¨ï¼è¿äºå½æ°çå¾ç´å°æ件对象 FILE ä¸å被ä¸ä¸ªä¸åç线ç¨éå®ï¼ç¶åéå®å®ï¼è¿è¡æéç I/O æä½ï¼å次对å®è§£éã

(注æï¼è¿ä¸ªéå®ä¸ç±å½æ° flock(2) å lockf(3) å®ç°çéå®æ å³ã)

ææè¿äºæä½å¯¹ C ç¨åºåæ¥è¯´é½æ¯ä¸å¯è§çï¼ä½æ¯æ两ç§çç±ï¼éè¦è¿è¡æ´åç»èçæ§å¶ãå¶ä¸ï¼ä¹è®¸æ个线ç¨éè¦è¿è¡ä¸å¯åå²çä¸ç³»å I/O æä½ï¼ä¸åºå½è¢«å¶ä»çº¿ç¨ç I/O æç»ç«¯ãå¶äºï¼åºäºæçå ç´ ï¼åºå½é¿åè¿è¡è¿å¤çéå®æ¥æé«æçã

为æ¤ï¼ä¸ä¸ªçº¿ç¨å¯ä»¥æ¾å¼å°éå®æ件对象 FILEï¼æ¥çè¿è¡å®çä¸ç³»å I/O æä½ï¼ç¶å解éãè¿æ·å¯ä»¥é¿åå¶ä»çº¿ç¨å¹²æ°ãå¦æè¿æ·åçååæ¯éè¦è¾¾å°æ´é«çæçï¼åºå½ä½¿ç¨ stdio å½æ°çééå®çæ¬æ¥è¿è¡ I/O æä½ï¼ä½¿ç¨ getc_unlocked() å putc_unlocked() æ¥ä»£æ¿ getc() å putc()ã

å½æ° flockfile() çå¾ *filehandle ä¸å被å¶ä»ç线ç¨éå®ï¼ç¶å使å½å线ç¨æ为 *filehandle çææèï¼ç¶åå¢å éå®è®¡æ° lockcountã

å½æ° funlockfile() åå°éå®è®¡æ°ã

å½æ° ftrylockfile() æ¯ flockfile() çééå®çæ¬ãå®å¨å¶ä»çº¿ç¨æ¥æ *filehandle æ¶ä¸åä»»ä½å¤çï¼å¦ååå¾æææ并å¢å éå®è®¡æ°ã

RETURN VALUE è¿åå¼

å½æ° ftrylockfile() è¿åé¶ï¼å¦ææåçè¯ (è·å¾äºéå®)ï¼å¦æ失败就è¿åéé¶ã

ERRORS

æ ã

AVAILABILITY

è¿äºå½æ°å½å®ä¹äº _POSIX_THREAD_SAFE_FUNCTIONS æ¶å¯ç¨ãå®ä»¬åå¨äº libc 5.1.1 ä¹åç libc çæ¬ä¸ï¼ä»¥å glibc 2.0 ä¹åç glibc çæ¬ä¸

CONFORMING TO æ ååè

POSIX.1

SEE ALSO åè§

unlocked_stdio(3)

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