contrib/list_example.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Copyright (C) 2021 by Andreas Fritiofson <andreas.fritiofson@gmail.com> */
   3
   4 /*
   5  * Simple example of using a circular doubly linked list through list.h
   6  *
   7  * gcc -I ../src/ list_example.c -o list_example
   8  */
   9
  10 #include <stdint.h>
  11 #include <stdbool.h>
  12 #include <assert.h>
  13 #include <helper/list.h>
  14
  15 static LIST_HEAD(threads);
  16
  17 struct thread {
  18         int id;
  19         uint64_t tcb_address;
  20         struct list_head lh;
  21 };
  22
  23 void insert(struct thread *t)
  24 {
  25         list_add_tail(&t->lh, &threads);
  26 }
  27
  28 void remove(struct thread *t)
  29 {
  30         list_del(&t->lh);
  31 }
  32
  33 struct thread *lookup_id(int id)
  34 {
  35         struct thread *t;
  36         list_for_each_entry(t, &threads, lh) {
  37                 if (t->id == id)
  38                         return t;
  39         }
  40         return NULL;
  41 }
  42
  43 struct thread *lookup_tcb(uint64_t addr)
  44 {
  45         struct thread *t;
  46         list_for_each_entry(t, &threads, lh) {
  47                 if (t->tcb_address == addr)
  48                         return t;
  49         }
  50         return NULL;
  51 }
  52
  53 int main(void)
  54 {
  55         struct thread t1 = { .id = 1, .tcb_address = 111111111 };
  56         struct thread t2 = { .id = 2, .tcb_address = 222222222 };
  57         struct thread t3 = { .id = 3, .tcb_address = 333333333 };
  58
  59         insert(&t1);
  60         insert(&t2);
  61         assert(lookup_id(1) == &t1);
  62         assert(lookup_tcb(111111111) == &t1);
  63         assert(lookup_id(2) == &t2);
  64         assert(lookup_id(42) == NULL);
  65         remove(&t1);
  66         assert(lookup_id(1) == NULL);
  67         insert(&t3);
  68         remove(&t2);
  69         assert(lookup_id(3) == &t3);
  70         assert(lookup_tcb(333333333) == &t3);
  71         assert(lookup_id(2) == NULL);
  72         remove(&t3);
  73         assert(list_empty(&threads));
  74 }