X-Git-Url: https://arthur.barton.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=plugins.d%2Floopsleepms.sh.inc;h=ef3db192d4a1bc9ea440748489739b83798d226e;hb=HEAD;hp=c0bbb5fdfadeb288abd47b1c67a4de98bc9f6c1e;hpb=8eb61a56540bc9cda5400172a337c18272707f4a;p=netdata.git diff --git a/plugins.d/loopsleepms.sh.inc b/plugins.d/loopsleepms.sh.inc index c0bbb5fd..ef3db192 100644 --- a/plugins.d/loopsleepms.sh.inc +++ b/plugins.d/loopsleepms.sh.inc @@ -1,90 +1,189 @@ -#!/bin/bash +# no need for shebang - this file is included from other scripts -# 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="$(which date)" +LOOPSLEEP_DATE="$(which date 2>/dev/null || command -v date 2>/dev/null)" if [ -z "$LOOPSLEEP_DATE" ] - then - echo >&2 "$0: ERROR: Cannot find the command 'date' in the system path." - exit 1 + then + echo >&2 "$0: ERROR: Cannot find the command 'date' in the system path." + exit 1 fi -LOOPSLEEPMS_LASTRUN=0 -LOOPSLEEPMS_LASTSLEEP=0 -LOOPSLEEPMS_LASTWORK=0 +# ----------------------------------------------------------------------------- +# use the date command as a high resolution timer +now_ms= LOOPSLEEPMS_HIGHRES=1 test "$($LOOPSLEEP_DATE +%N)" = "%N" && LOOPSLEEPMS_HIGHRES=0 +test -z "$($LOOPSLEEP_DATE +%N)" && LOOPSLEEPMS_HIGHRES=0 +current_time_ms_from_date() { + if [ $LOOPSLEEPMS_HIGHRES -eq 0 ] + then + now_ms="$($LOOPSLEEP_DATE +'%s')000" + else + now_ms="$(( $( $LOOPSLEEP_DATE +'%s * 1000 + %-N / 1000000' ) ))" + fi +} -now_ms= -current_time_ms() { - # if high resolution is not supported - # just sleep the time requested, in seconds - if [ $LOOPSLEEPMS_HIGHRES -eq 0 ] - then - now_ms="$($LOOPSLEEP_DATE +'%s')000" - else - now_ms="$(( $( $LOOPSLEEP_DATE +'%s * 1000 + %-N / 1000000' ) ))" - fi +# ----------------------------------------------------------------------------- +# use /proc/uptime as a high resolution timer + +current_time_ms_from_date +current_time_ms_from_uptime_started="${now_ms}" +current_time_ms_from_uptime_last="${now_ms}" +current_time_ms_from_uptime_first=0 +current_time_ms_from_uptime() { + local up rest arr=() n + + read up rest &2 "$0: Cannot read /proc/uptime - falling back to current_time_ms_from_date()." + current_time_ms="current_time_ms_from_date" + current_time_ms_from_date + current_time_ms_accuracy=1 + return + fi + + arr=(${up//./ }) + + if [ ${#arr[1]} -lt 1 ] + then + n="${arr[0]}000" + elif [ ${#arr[1]} -lt 2 ] + then + n="${arr[0]}${arr[1]}00" + elif [ ${#arr[1]} -lt 3 ] + then + n="${arr[0]}${arr[1]}0" + else + n="${arr[0]}${arr[1]}" + fi + + now_ms=$((current_time_ms_from_uptime_started - current_time_ms_from_uptime_first + n)) + + if [ "${now_ms}" -lt "${current_time_ms_from_uptime_last}" ] + then + echo >&2 "$0: Cannot use current_time_ms_from_uptime() - new time ${now_ms} is older than the last ${current_time_ms_from_uptime_last} - falling back to current_time_ms_from_date()." + current_time_ms="current_time_ms_from_date" + current_time_ms_from_date + current_time_ms_accuracy=1 + fi + + current_time_ms_from_uptime_last="${now_ms}" +} +current_time_ms_from_uptime +current_time_ms_from_uptime_first="$((now_ms - current_time_ms_from_uptime_started))" +current_time_ms_from_uptime_last="${current_time_ms_from_uptime_first}" +current_time_ms="current_time_ms_from_uptime" +current_time_ms_accuracy=10 +if [ "${current_time_ms_from_uptime_first}" -eq 0 ] + then + echo >&2 "$0: Invalid setup for current_time_ms_from_uptime() - falling back to current_time_ms_from_date()." + current_time_ms="current_time_ms_from_date" + current_time_ms_accuracy=1 +fi + +# ----------------------------------------------------------------------------- +# use read with timeout for sleep + +mysleep="mysleep_read" + +mysleep_fifo="${NETDATA_CACHE_DIR-/tmp}/.netdata_bash_sleep_timer_fifo" +[ ! -e "${mysleep_fifo}" ] && mkfifo "${mysleep_fifo}" +[ ! -e "${mysleep_fifo}" ] && mysleep="sleep" + +mysleep_read() { + read -t "${1}" <>"${mysleep_fifo}" + ret=$? + if [ $ret -le 128 ] + then + echo >&2 "$0: Cannot use read for sleeping (return code ${ret})." + mysleep="sleep" + ${mysleep} "${1}" + fi } + +# ----------------------------------------------------------------------------- +# 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. + +LOOPSLEEPMS_LASTRUN=0 +LOOPSLEEPMS_NEXTRUN=0 +LOOPSLEEPMS_LASTSLEEP=0 +LOOPSLEEPMS_LASTWORK=0 + 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 + local tellwork=0 t="${1}" div s m now mstosleep + + if [ "${t}" = "tellwork" ] + then + tellwork=1 + shift + t="${1}" + fi + + # $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 in ${now_ms} + ${current_time_ms} + + # calculate ms since last run + [ ${LOOPSLEEPMS_LASTRUN} -gt 0 ] && \ + LOOPSLEEPMS_LASTWORK=$((now_ms - LOOPSLEEPMS_LASTRUN - LOOPSLEEPMS_LASTSLEEP + current_time_ms_accuracy)) + # echo "# last loop's work took $LOOPSLEEPMS_LASTWORK ms" + + # remember this run + LOOPSLEEPMS_LASTRUN=${now_ms} + + # calculate the next run + LOOPSLEEPMS_NEXTRUN=$(( ( now_ms - ( now_ms % ( t * 1000 ) ) ) + ( t * 1000 ) )) + + # calculate ms to sleep + mstosleep=$(( LOOPSLEEPMS_NEXTRUN - now_ms + current_time_ms_accuracy )) + # echo "# mstosleep is $mstosleep ms" + + # if we are too slow, sleep some time + test ${mstosleep} -lt 200 && mstosleep=200 + + s=$(( mstosleep / 1000 )) + m=$(( mstosleep - (s * 1000) )) + [ "${m}" -lt 100 ] && m="0${m}" + [ "${m}" -lt 10 ] && m="0${m}" + + 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 + ${mysleep} ${s}.${m} + + # keep the values we need + # for our next run + LOOPSLEEPMS_LASTSLEEP=$mstosleep } + +# test it +#while [ 1 ] +#do +# r=$(( (RANDOM * 2000 / 32767) )) +# s=$((r / 1000)) +# m=$((r - (s * 1000))) +# [ "${m}" -lt 100 ] && m="0${m}" +# [ "${m}" -lt 10 ] && m="0${m}" +# echo "${r} = ${s}.${m}" +# +# # the work +# ${mysleep} ${s}.${m} +# +# # the alignment loop +# loopsleepms tellwork 1 +#done