libuv源码阅读(10)-thread-create

#include <stdio.h>
#include <unistd.h>

#include <uv.h>

void hare(void *arg) {
    int tracklen = *((int *) arg);
    while (tracklen) {
        tracklen--;
        sleep(1);
        fprintf(stderr, "Hare ran another step\n");
    }
    fprintf(stderr, "Hare done running!\n");
}

void tortoise(void *arg) {
    int tracklen = *((int *) arg);
    while (tracklen) {
        tracklen--;
        fprintf(stderr, "Tortoise ran another step\n");
        sleep(3);
    }
    fprintf(stderr, "Tortoise done running!\n");
}

int main() {
    int tracklen = 10;
    uv_thread_t hare_id;
    uv_thread_t tortoise_id;
    uv_thread_create(&hare_id, hare, &tracklen);
    uv_thread_create(&tortoise_id, tortoise, &tracklen);

    uv_thread_join(&hare_id);
    uv_thread_join(&tortoise_id);
    return 0;
}

struct uv_thread_options_s {
  unsigned int flags;
  size_t stack_size;
  /* More fields may be added at any time. */
};

int uv_thread_create(uv_thread_t *tid, void (*entry)(void *arg), void *arg) {
  uv_thread_options_t params;
  params.flags = UV_THREAD_NO_FLAGS;
  return uv_thread_create_ex(tid, &params, entry, arg);
}

int uv_thread_create_ex(uv_thread_t* tid,
                        const uv_thread_options_t* params,
                        void (*entry)(void *arg),
                        void *arg) {
  int err;
  pthread_attr_t* attr;
  pthread_attr_t attr_storage;
  size_t pagesize;
  size_t stack_size;

  /* Used to squelch a -Wcast-function-type warning. */
  union {
    void (*in)(void*);
    void* (*out)(void*);
  } f;

  stack_size =
      params->flags & UV_THREAD_HAS_STACK_SIZE ? params->stack_size : 0;

  attr = NULL;
  if (stack_size == 0) {
    stack_size = thread_stack_size();
  } else {
    pagesize = (size_t)getpagesize();
    /* Round up to the nearest page boundary. */
    stack_size = (stack_size + pagesize - 1) &~ (pagesize - 1);
#ifdef PTHREAD_STACK_MIN
    if (stack_size < PTHREAD_STACK_MIN)
      stack_size = PTHREAD_STACK_MIN;
#endif
  }

  if (stack_size > 0) {
    attr = &attr_storage;

    if (pthread_attr_init(attr))
      abort();

    if (pthread_attr_setstacksize(attr, stack_size))
      abort();
  }

  f.in = entry;
  err = pthread_create(tid, attr, f.out, arg);

  if (attr != NULL)
    pthread_attr_destroy(attr);

  return UV__ERR(err);
}