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

4486

4487 /* Decrement the in-core usage count of a shared text

4488  * segment. When it drops to zero, free the core space.

4489  */

4490 xccdec(xp)

4491 int *xp;

4492 {

4493     register *rp;

4494

4495     if((rp=xp)!=NULL && rp->x_ccount!=0)

4496          if(--rp->x_ccount == 0)

4497           mfree(coremap, rp->x_size, rp->x_caddr);

• x_ccount - 1
• 若x_ccount 为0,释放对应内存空间

4498 }

4499

• 进程图像
• 共享正文段

• code:xswap
• code:xfree