code:cinit - ikarishinjieva/unixV6-code-analyze-chs GitHub Wiki

8231 /* Initialize clist by freeing all character blocks, & count 8281

8232 * number of character devices. (Once-only routine)

8233 */

8234 cinit()

8235 {

8236 register int ccp;

8237 register struct cblock *cp;

8238 register struct cdevsw *cdp;

8239 ccp = cfree;

ccp 指向 cfree数组的头部

8240 for (cp=(ccp+07)&~07; cp <= &cfree[NCLIST-1]; cp++) {

8241 cp->c_next = cfreelist;

8242 cfreelist = cp;

8243 }

寻找cfree数组中第一个为8整数倍的地址

将该地址作为第一个字符缓存的起始地址,并顺次构成接下来的缓存,依次加入到自由字符缓存队列中

参看缓存池的改造

8244 ccp = 0;

8245 for(cdp = cdevsw; cdp->d_open; cdp++)

8246 ccp++;

8247 nchrdev = ccp;

遍历cdevsw数组,统计字符设备数,并赋给 nchrdev

8248 }

8249 /* ------------------------- */