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

4393

4394 /*

4395 * relinquish use of the shared text segment

4396 * of a process.

4397 */

4398 xfree()

4399 { register *xp, *ip;

4400

4401 if((xp=u.u_procp->p_textp) != NULL) {

4402 u.u_procp->p_textp == NULL;

4403 xccdec(xp);

释放当前内存共享正文段的内存引用

4404 if(--xp->x_count == 0) {

4405 ip = xp->x_iptr;

4406 if((ip->i_mode&ISVTX) == 0) {

4407 xp->x_iptr = NULL;

4408 mfree(swapmap, (xp->x_size+7)/8,

4409 xp->x_daddr);

4410 ip->i_flag =& ~ITEXT;

4411 iput(ip);

4412 }

4413 }

释放共享正文段的引用

若释放引用后引用数为0，且未置ISVTX(inode.h)

释放盘交换区空间

释放 INODE

4414 }

4415 }

4416 /* ------------------------- */