main.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <aio.h>

static void
read_done(union sigval sigval)
{
  struct aiocb *cb;
  int n;

  cb = (struct aiocb*)sigval.sival_ptr;

  printf("CB\n");

  if (aio_error(cb) == 0) {
    n = aio_return(cb);
    if (n == 0) { /* EOF */
      printf("client %d gone\n", cb->aio_fildes);
      aio_cancel(cb->aio_fildes, cb);
      close(cb->aio_fildes);
      free(cb);
      return;
    }
    printf("client %d (%d)\n", cb->aio_fildes, n);
    write(cb->aio_fildes, (void*)cb->aio_buf, n);
    aio_read(cb);
  }
  else {
    perror("aio_return");
    return;
  }

  return;
}

static void
register_read(int fd)
{
  struct aiocb *cb;
  char *buf;
  int ret;

  printf("client %d registerd\n", fd);
  cb = malloc(sizeof(struct aiocb));
  buf = malloc(BUFSIZ);

  memset(cb, 0, sizeof(struct aiocb));

  cb->aio_offset = 0;
  cb->aio_reqprio = 0;
  cb->aio_fildes = fd;
  cb->aio_buf = buf;
  cb->aio_nbytes = BUFSIZ;

  cb->aio_sigevent.sigev_notify = SIGEV_THREAD;
  cb->aio_sigevent.sigev_notify_function = read_done;
  cb->aio_sigevent.sigev_value.sival_ptr = cb;

  if(aio_read(cb) != 0) {
    printf( "aio_read : %d : %s\n", errno, strerror( errno ) );
  }
}

int
main()
{
  struct sockaddr_in addr;
  int s = socket(PF_INET, SOCK_STREAM, 0);

  addr.sin_family = AF_INET;
  addr.sin_addr.s_addr = INADDR_ANY;
  addr.sin_port = htons(9989);
  if (bind(s, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
    perror("bind");
    exit(1);
  }
  listen(s, 5);

  for (;;) {
    int c = accept(s, NULL, 0);
    if (c < 0) continue;

    register_read(c);
  }
}

async_io(スレッド)を使ったエコーサーバ
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