Sigh ... Do not send mail when tired. Was thinking of different problem.
Ron
On 3/22/09, ron minnich <rminn...@gmail.com> wrote:
> This is from mobile so I can not look at code much but if you are
> converting nanoseconds to milliseconds you multiply by 1e6 not 1e-6 I
> think.
>
> Ron
>
> On 3/22/09, cinap_len...@gmx.de <cinap_len...@gmx.de> wrote:
>> This is actualy very interesting. Riped the parts from periodic.c
>> to play a with the code to see how it reacts to some changes.
>>
>> The code below reproduces the problem:
>>
>> sleep()+0x7 /sys/src/libc/9syscall/sleep.s:5
>> periodicThread(msec=0x3e8)+0xb2 /tmp/a.c:21
>> ct=0x47a68e5b
>> t=0x47e50e4d
>> ts=0x0
>> main()+0x10 /tmp/a.c:32
>> _main+0x31 /sys/src/libc/386/main9.s:16
>>
>>
>> The zerosleeps go away if one uncomments the foo print. It also
>> goes away if one makes the sleep one milli second longer by
>> changing ts to ts+1.
>>
>> I would love if anybody gives a good explaination of this bug
>> and how to fix it :-)
>>
>> #include <u.h>
>> #include <libc.h>
>>
>> static void
>> periodicThread(int msec)
>> {
>> double t, ct, ts;
>>
>> ct = nsec()*1e-6;
>> t = ct + msec;
>>
>> for(;;){
>> /* skip missed */
>> while(t <= ct)
>> t += msec;
>>
>> ts = t - ct;
>> if(ts > 1000)
>> ts = 1000;
>> sleep(ts);
>> ct = nsec()*1e-6;
>> if(t <= ct){
>> // print("foo!\n");
>> t += msec;
>> }
>> }
>> }
>>
>> void
>> main(int argc, char *argv[])
>> {
>> periodicThread(1000);
>> }
>>
>
> --
> Sent from my mobile device
>
--
Sent from my mobile device
