Timers.cpp revision ea659643ee1b0c46e473619034cd130440405ac4 
1/*
2 * Copyright (C) 2005 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17//
18// Timer functions.
19//
20#include <utils/Timers.h>
21#include <utils/Log.h>
22
23#include <stdlib.h>
24#include <stdio.h>
25#include <unistd.h>
26#include <sys/time.h>
27#include <time.h>
28#include <errno.h>
29#include <limits.h>
30
31#ifdef HAVE_WIN32_THREADS
32#include <windows.h>
33#endif
34
35nsecs_t systemTime(int clock)
36{
37#if defined(HAVE_ANDROID_OS)
38    static const clockid_t clocks[] = {
39            CLOCK_REALTIME,
40            CLOCK_MONOTONIC,
41            CLOCK_PROCESS_CPUTIME_ID,
42            CLOCK_THREAD_CPUTIME_ID,
43            CLOCK_BOOTTIME
44    };
45    struct timespec t;
46    t.tv_sec = t.tv_nsec = 0;
47    clock_gettime(clocks[clock], &t);
48    return nsecs_t(t.tv_sec)*1000000000LL + t.tv_nsec;
49#else
50    // Clock support varies widely across hosts. Mac OS doesn't support
51    // posix clocks, older glibcs don't support CLOCK_BOOTTIME and Windows
52    // is windows.
53    struct timeval t;
54    t.tv_sec = t.tv_usec = 0;
55    gettimeofday(&t, NULL);
56    return nsecs_t(t.tv_sec)*1000000000LL + nsecs_t(t.tv_usec)*1000LL;
57#endif
58}
59
60int toMillisecondTimeoutDelay(nsecs_t referenceTime, nsecs_t timeoutTime)
61{
62    int timeoutDelayMillis;
63    if (timeoutTime > referenceTime) {
64        uint64_t timeoutDelay = uint64_t(timeoutTime - referenceTime);
65        if (timeoutDelay > uint64_t((INT_MAX - 1) * 1000000LL)) {
66            timeoutDelayMillis = -1;
67        } else {
68            timeoutDelayMillis = (timeoutDelay + 999999LL) / 1000000LL;
69        }
70    } else {
71        timeoutDelayMillis = 0;
72    }
73    return timeoutDelayMillis;
74}
75