1 # this function is used to sleep a fraction of a second
2 # it calculates the difference between every time is called
3 # and tries to align the sleep time to give you exactly the
8 LOOPSLEEPMS_LASTSLEEP=0
13 test `date +%N` = "%N" && LOOPSLEEPMS_HIGHRES=0
18 # check if high resolution timer is supported
19 test $LOOPSLEEPMS_HIGHRES -eq 2 && check_high_res
21 # if high resolution is not supported
22 # just sleep the time requested, in seconds
23 if [ $LOOPSLEEPMS_HIGHRES -eq 0 ]
25 local s="`date +'%s'`"
28 local d="`date +'%s.%N'`"
29 local s="`echo $d | cut -d '.' -f 1`"
30 local m="`echo $d | cut -d '.' -f 2 | cut -b 1-3`"
37 if [ "$1" = "tellwork" ]
43 # the time in seconds to wait, as the first argument
46 # check if high resolution timer is supported
47 test $LOOPSLEEPMS_HIGHRES -eq 2 && check_high_res
49 # if high resolution is not supported
50 # just sleep the time requested, in seconds
51 if [ $LOOPSLEEPMS_HIGHRES -eq 0 ]
57 # get the current time
58 local d="`date +'%s.%N'`"
59 local s="`echo $d | cut -d '.' -f 1`"
60 local m="`echo $d | cut -d '.' -f 2 | cut -b 1-3`"
61 local now="$s$m" # milliseconds since epoch (1-1-1970)
63 # calculate required sleep in ms
66 # this is our first run
67 # just wait the requested time
68 test $LOOPSLEEPMS_LASTRUN -eq 0 && LOOPSLEEPMS_LASTRUN=$now
70 # calculate ms since last run
71 LOOPSLEEPMS_LASTWORK=$((now - LOOPSLEEPMS_LASTRUN - LOOPSLEEPMS_LASTSLEEP))
72 # echo "# last loop's work took $LOOPSLEEPMS_LASTWORK ms"
74 test $tellwork -eq 1 && echo >&2 " >>> PERFORMANCE >>> WORK TOOK $LOOPSLEEPMS_LASTWORK ms ( $((LOOPSLEEPMS_LASTWORK * 100 / 1000)).$((LOOPSLEEPMS_LASTWORK % 10))% cpu )"
76 # calculate ms to sleep
77 local mstosleep=$((t - LOOPSLEEPMS_LASTWORK))
78 # echo "# mstosleep is $mstosleep ms"
80 # if we are too slow, sleep some time
81 test $mstosleep -lt $((t / 2)) && mstosleep=$((t / 2))
83 local s=$((mstosleep / 1000))
84 local m=$((mstosleep - (s * 1000)))
86 # echo "# sleeping $s.$m"
90 # keep the values we need
92 LOOPSLEEPMS_LASTRUN=$now
93 LOOPSLEEPMS_LASTSLEEP=$mstosleep