 1#include <stdlib.h>
 2#include <stdio.h>
 3#include <string.h>
 4#include <stdatomic.h>
 5#include <assert.h>
 6#include <unistd.h>
 7#include <pthread.h>
 8
 9#define NTHREAD 64
10enum { T_FREE = 0, T_LIVE, T_DEAD, };
11struct thread {
12  int id, status;
13  pthread_t thread;
14  void (*entry)(int);
15};
16
17struct thread tpool[NTHREAD], *tptr = tpool;
18
19void *wrapper(void *arg) {
20  struct thread *thread = (struct thread *)arg;
21  thread->entry(thread->id);
22  return NULL;
23}
24
25void create(void *fn) {
26  assert(tptr - tpool < NTHREAD);
27  *tptr = (struct thread) {
28    .id = tptr - tpool + 1,
29    .status = T_LIVE,
30    .entry = fn,
31  };
32  pthread_create(&(tptr->thread), NULL, wrapper, tptr);
33  ++tptr;
34}
35
36void join() {
37  for (int i = 0; i < NTHREAD; i++) {
38    struct thread *t = &tpool[i];
39    if (t->status == T_LIVE) {
40      pthread_join(t->thread, NULL);
41      t->status = T_DEAD;
42    }
43  }
44}
45
46__attribute__((destructor)) void cleanup() {
47  join();
48}
20. C 标准库和实现¶

Take-away Messages¶

课后习题/编程作业¶

1. 编程实践¶
