diff options
Diffstat (limited to 'plugins.d/loopsleepms.sh.inc')
-rw-r--r-- | plugins.d/loopsleepms.sh.inc | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/plugins.d/loopsleepms.sh.inc b/plugins.d/loopsleepms.sh.inc new file mode 100644 index 000000000..2e22de3d8 --- /dev/null +++ b/plugins.d/loopsleepms.sh.inc @@ -0,0 +1,90 @@ +#!/bin/bash + +# this function is used to sleep a fraction of a second +# it calculates the difference between every time is called +# and tries to align the sleep time to give you exactly the +# loop you need. + +LOOPSLEEP_DATE="$(which date)" +if [ -z "$LOOPSLEEP_DATE" ] + then + echo >&2 "$0: ERROR: Cannot find the command 'date' in the system path." + exit 1 +fi + +LOOPSLEEPMS_LASTRUN=0 +LOOPSLEEPMS_LASTSLEEP=0 +LOOPSLEEPMS_LASTWORK=0 + +LOOPSLEEPMS_HIGHRES=1 +test "$($LOOPSLEEP_DATE +%N)" = "%N" && LOOPSLEEPMS_HIGHRES=0 + +now_ms= +current_time_ms() { + # if high resolution is not supported + # just sleep the time requested, in seconds + if [ $LOOPSLEEPMS_HIGHRES -eq 0 ] + then + now_ms="$($LOOPSLEEP_DATE +'%s')000" + else + now_ms="$(( $( $LOOPSLEEP_DATE +'%s * 1000 + %-N / 1000000' ) ))" + fi +} + +loopsleepms() { + local tellwork=0 t="$1" div s m now mstosleep + + if [ "$t" = "tellwork" ] + then + tellwork=1 + shift + t="$1" + fi + div="${2-100}" + + # $t = the time in seconds to wait + + # if high resolution is not supported + # just sleep the time requested, in seconds + if [ $LOOPSLEEPMS_HIGHRES -eq 0 ] + then + sleep $t + return + fi + + # get the current time, in ms + # milliseconds since epoch (1-1-1970) + now="$(( $( $LOOPSLEEP_DATE +'%s * 1000 + %-N / 1000000' ) ))" + + # calculate required sleep in ms + t=$((t * 1000 * div / 100)) + + # this is our first run + # just wait the requested time + test $LOOPSLEEPMS_LASTRUN -eq 0 && LOOPSLEEPMS_LASTRUN=$now + + # calculate ms since last run + LOOPSLEEPMS_LASTWORK=$((now - LOOPSLEEPMS_LASTRUN - LOOPSLEEPMS_LASTSLEEP)) + # echo "# last loop's work took $LOOPSLEEPMS_LASTWORK ms" + + # calculate ms to sleep + mstosleep=$(( t - LOOPSLEEPMS_LASTWORK )) + # echo "# mstosleep is $mstosleep ms" + + # if we are too slow, sleep some time + test $mstosleep -lt 200 && mstosleep=200 + + s=$((mstosleep / 1000)) + m=$((mstosleep - (s * 1000))) + + test $tellwork -eq 1 && echo >&2 " >>> PERFORMANCE >>> WORK TOOK $LOOPSLEEPMS_LASTWORK ms ( $((LOOPSLEEPMS_LASTWORK * 100 / 1000)).$((LOOPSLEEPMS_LASTWORK % 10))% cpu ) >>> SLEEPING $mstosleep ms" + + # echo "# sleeping $s.$m" + # echo + sleep $s.$m + + # keep the values we need + # for our next run + LOOPSLEEPMS_LASTRUN=$now + LOOPSLEEPMS_LASTSLEEP=$mstosleep +} |