[英]Uptime iOS Objective-C - millisecond precision
I'm trying to get uptime for iOS. 我正试图让iOS的正常运行时间。 I was using mach_absolute_time - but I found that it paused during sleep.
我正在使用mach_absolute_time - 但我发现它在睡眠时暂停了。
I found this snippet: 我找到了这个片段:
- (time_t)uptime
{
struct timeval boottime;
int mib[2] = {CTL_KERN, KERN_BOOTTIME};
size_t size = sizeof(boottime);
time_t now;
time_t uptime = -1;
(void)time(&now);
if (sysctl(mib, 2, &boottime, &size, NULL, 0) != -1 && boottime.tv_sec != 0)
{
uptime = now - boottime.tv_sec;
}
return uptime;
}
It does the trick. 它成功了。 BUT, it's returning whole seconds.
但是,它整整回来了。 Any way to get milliseconds out of this?
有什么方法可以获得毫秒数?
The kernel does not (apparently) store a higher-resolution timestamp of its boot time. 内核(显然)不会存储其启动时间的更高分辨率时间戳。
KERN_BOOTTIME
is implemented by the sysctl_boottime
function in bsd/kern/kern_sysctl.c
. KERN_BOOTTIME
由bsd/kern/kern_sysctl.c
的sysctl_boottime
函数实现。 It calls boottime_sec
. 它调用
boottime_sec
。
boottime_sec
is implemented in bsd/kern/kern_time.c
. boottime_sec
在bsd/kern/kern_time.c
。 It calls clock_get_boottime_nanotime
, which has a promising name. 它调用
clock_get_boottime_nanotime
,它有一个很有希望的名字。
clock_get_boottime_nanotime
is implemented in osfmk/kern/clock.c
. clock_get_boottime_nanotime
在osfmk/kern/clock.c
。 It is hard-coded to always return 0 in its nanosecs
argument. 硬编码总是在
nanosecs
参数中返回0。
If you want something pure Objective-C, try 如果你想要纯粹的Objective-C,试试吧
NSTimeInterval uptime = [[NSProcessInfo processInfo] systemUptime];
( NSTimeInterval
is a typedef for double
, representing seconds.) (
NSTimeInterval
是double
的typedef,表示秒。)
I know it's probably too late, but there you go: 我知道这可能为时已晚,但你去了:
+ (NSTimeInterval)uptime {
struct timeval boottime;
int mib[2] = {CTL_KERN, KERN_BOOTTIME};
size_t size = sizeof(boottime);
struct timeval now;
struct timezone tz;
gettimeofday(&now, &tz);
double uptime = -1;
if (sysctl(mib, 2, &boottime, &size, NULL, 0) != -1 && boottime.tv_sec != 0) {
uptime = now.tv_sec - boottime.tv_sec;
uptime += (double)(now.tv_usec - boottime.tv_usec) / 1000000.0;
}
return uptime;
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.