1/*
2 * Copyright 2012 Google, Inc
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15#include "sync.h"
16#include <errno.h>
17#include <poll.h>
18#include <stdio.h>
19
20int SyncWait(int num, int time)
21{
22    struct pollfd work;
23    int result;
24
25    if (num < 0) {
26        errno = EINVAL;
27        return -1;
28    }
29
30    work.fd = num;
31    work.events = POLLIN;
32
33    do {
34        result = poll(&work, 1, time);
35        if (result > 0) {
36            if (work.revents & (POLLERR | POLLNVAL)) {
37                errno = EINVAL;
38                return -1;
39            }
40            return 0;
41        } else if (result == 0) {
42            errno = ETIME;
43            return -1;
44        }
45    } while (result == -1 && (errno == EINTR || errno == EAGAIN));
46
47    return result;
48}
49