malloc.c -- unlink

unlink.c

#define unlink(AV, P, BK, FD) {                                            
        FD = P->fd;                                                                      
        BK = P->bk;                                                                      
        if (__builtin_expect (FD->bk != P || BK->fd != P, 0))                      
            malloc_printerr (check_action, "corrupted double-linked list", P, AV);  
        else {                                                                     
            FD->bk = BK;                                                              
            BK->fd = FD;                                                              
            if (!in_smallbin_range (P->size)                                      
                && __builtin_expect (P->fd_nextsize != NULL, 0)) {                      
                    if (__builtin_expect (P->fd_nextsize->bk_nextsize != P, 0)  
                        || __builtin_expect (P->bk_nextsize->fd_nextsize != P, 0))    
                            malloc_printerr (check_action, 
                                            "corrupted double-linked list (not small)",    
                                             P, AV);       
                    if (FD->fd_nextsize == NULL) {                                      
                        if (P->fd_nextsize == P)                                      
                            FD->fd_nextsize = FD->bk_nextsize = FD;                      
                        else {                                                          
                            FD->fd_nextsize = P->fd_nextsize;                              
                            FD->bk_nextsize = P->bk_nextsize;                             
                            P->fd_nextsize->bk_nextsize = FD;                              
                            P->bk_nextsize->fd_nextsize = FD;                              
                        }                                                              
                    } else {                                                              
                        P->fd_nextsize->bk_nextsize = P->bk_nextsize;                      
                        P->bk_nextsize->fd_nextsize = P->fd_nextsize;                      
                    }                                                                      
           }                                                                      
     }                                                                              
}