Re: [Mingw-w64-public] [PATCH 1/2] Round up when converting nanoseconds to milliseconds
在 2019/3/1 19:08, LRN 写道: > > New version is attached. > > > OK, pushed this one. -- Best regards, LH_Mouse ___ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
Re: [Mingw-w64-public] [PATCH 1/2] Round up when converting nanoseconds to milliseconds
On 01.03.2019 5:48, Liu Hao wrote:
> 在 2019/3/1 上午2:09, LRN 写道:
>> If the caller provides ts_nsec in struct timespec,
>> we lose precision when converting that time to milliseconds
>> for our WaitFor*() calls. Make sure we round *up* when doing that
>> conversion, as otherwise the wait time will be *less* than the caller
>> expects. Users of pthreads on non-realtime systems are generally
>> OK with functions returning a bit later than requested. But timing out
>> *earlier* than the requested time is completely unexpected.
>> ---
>> mingw-w64-libraries/winpthreads/src/misc.c | 13 -
>> 1 file changed, 12 insertions(+), 1 deletion(-)
>>
>>
>>
>
> This seems an overkill. There is a much simpler solution:
>
> ```
> t += (unsigned long long) (ts->tv_nsec + 99) / 100;
> ```
>
>
New version is attached.
From 59fb104b98567fd4a56444daa4382e9e43279856 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=A0=D1=83=D1=81=D0=BB=D0=B0=D0=BD=20=D0=98=D0=B6=D0=B1?=
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Date: Thu, 28 Feb 2019 17:49:49 +
Subject: [PATCH 1/2] Round up when converting nanoseconds to milliseconds
If the caller provides ts_nsec in struct timespec,
we lose precision when converting that time to milliseconds
for our WaitFor*() calls. Make sure we round *up* when doing that
conversion, as otherwise the wait time will be *less* than the caller
expects. Users of pthreads on non-realtime systems are generally
OK with functions returning a bit later than requested. But timing out
*earlier* than the requested time is completely unexpected.
---
mingw-w64-libraries/winpthreads/src/misc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mingw-w64-libraries/winpthreads/src/misc.c
b/mingw-w64-libraries/winpthreads/src/misc.c
index ab0488c..d8753f2 100644
--- a/mingw-w64-libraries/winpthreads/src/misc.c
+++ b/mingw-w64-libraries/winpthreads/src/misc.c
@@ -36,7 +36,8 @@ unsigned long long _pthread_time_in_ms(void)
unsigned long long _pthread_time_in_ms_from_timespec(const struct timespec *ts)
{
unsigned long long t = (unsigned long long) ts->tv_sec * 1000LL;
-t += (unsigned long long) (ts->tv_nsec / 100);
+/* The +99 is here to ensure that the division always rounds up */
+t += (unsigned long long) (ts->tv_nsec + 99) / 100;
return t;
}
--
2.4.0
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Re: [Mingw-w64-public] [PATCH 1/2] Round up when converting nanoseconds to milliseconds
On 01.03.2019 5:48, Liu Hao wrote: > 在 2019/3/1 上午2:09, LRN 写道: >> If the caller provides ts_nsec in struct timespec, >> we lose precision when converting that time to milliseconds >> for our WaitFor*() calls. Make sure we round *up* when doing that >> conversion, as otherwise the wait time will be *less* than the caller >> expects. Users of pthreads on non-realtime systems are generally >> OK with functions returning a bit later than requested. But timing out >> *earlier* than the requested time is completely unexpected. >> --- >> mingw-w64-libraries/winpthreads/src/misc.c | 13 - >> 1 file changed, 12 insertions(+), 1 deletion(-) >> >> >> > > This seems an overkill. There is a much simpler solution: > > ``` > t += (unsigned long long) (ts->tv_nsec + 99) / 100; > ``` > > I don't care how it works, as long as it works :) signature.asc Description: OpenPGP digital signature ___ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
Re: [Mingw-w64-public] [PATCH 1/2] Round up when converting nanoseconds to milliseconds
在 2019/3/1 上午2:09, LRN 写道: > If the caller provides ts_nsec in struct timespec, > we lose precision when converting that time to milliseconds > for our WaitFor*() calls. Make sure we round *up* when doing that > conversion, as otherwise the wait time will be *less* than the caller > expects. Users of pthreads on non-realtime systems are generally > OK with functions returning a bit later than requested. But timing out > *earlier* than the requested time is completely unexpected. > --- > mingw-w64-libraries/winpthreads/src/misc.c | 13 - > 1 file changed, 12 insertions(+), 1 deletion(-) > > > This seems an overkill. There is a much simpler solution: ``` t += (unsigned long long) (ts->tv_nsec + 99) / 100; ``` -- Best regards, LH_Mouse signature.asc Description: OpenPGP digital signature ___ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
