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Diffstat (limited to 'collectors/charts.d.plugin/loopsleepms.sh.inc')
| -rw-r--r-- | collectors/charts.d.plugin/loopsleepms.sh.inc | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/collectors/charts.d.plugin/loopsleepms.sh.inc b/collectors/charts.d.plugin/loopsleepms.sh.inc new file mode 100644 index 000000000..bdc032b99 --- /dev/null +++ b/collectors/charts.d.plugin/loopsleepms.sh.inc @@ -0,0 +1,237 @@ +# no need for shebang - this file is included from other scripts +# SPDX-License-Identifier: GPL-3.0-or-later + +LOOPSLEEP_DATE="$(which date 2>/dev/null || command -v date 2>/dev/null)" +if [ -z "$LOOPSLEEP_DATE" ] + then + echo >&2 "$0: ERROR: Cannot find the command 'date' in the system path." + exit 1 +fi + +# ----------------------------------------------------------------------------- +# use the date command as a high resolution timer + +now_ms= +LOOPSLEEPMS_HIGHRES=1 +test "$($LOOPSLEEP_DATE +%N)" = "%N" && LOOPSLEEPMS_HIGHRES=0 +test -z "$($LOOPSLEEP_DATE +%N)" && LOOPSLEEPMS_HIGHRES=0 +current_time_ms_from_date() { + if [ $LOOPSLEEPMS_HIGHRES -eq 0 ] + then + now_ms="$($LOOPSLEEP_DATE +'%s')000" + else + now_ms="$(( $( $LOOPSLEEP_DATE +'%s * 1000 + %-N / 1000000' ) ))" + fi +} + +# ----------------------------------------------------------------------------- +# use /proc/uptime as a high resolution timer + +current_time_ms_from_date +current_time_ms_from_uptime_started="${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 </proc/uptime + if [ $? -ne 0 ] + then + echo >&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 "$0: Invalid setup for current_time_ms_from_uptime() - falling back to current_time_ms_from_date()." + current_time_ms="current_time_ms_from_date" + current_time_ms_accuracy=1 +fi + +# ----------------------------------------------------------------------------- +# use read with timeout for sleep + +mysleep="" + +mysleep_fifo="${NETDATA_CACHE_DIR-/tmp}/.netdata_bash_sleep_timer_fifo" +[ -f "${mysleep_fifo}" ] && rm "${mysleep_fifo}" +[ ! -p "${mysleep_fifo}" ] && mkfifo "${mysleep_fifo}" +[ -p "${mysleep_fifo}" ] && mysleep="mysleep_read" + +mysleep_read() { + read -t "${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 +} + +# ----------------------------------------------------------------------------- +# use bash loadable module for sleep + +mysleep_builtin() { + builtin sleep "${1}" + ret=$? + if [ $ret -ne 0 ] + then + echo >&2 "$0: Cannot use builtin sleep for sleeping (return code ${ret})." + mysleep="sleep" + ${mysleep} "${1}" + fi +} + +if [ -z "${mysleep}" -a "$((BASH_VERSINFO[0] +0))" -ge 3 -a "${NETDATA_BASH_LOADABLES}" != "DISABLE" ] + then + # enable modules only for bash version 3+ + + for bash_modules_path in ${BASH_LOADABLES_PATH//:/ } "$(pkg-config bash --variable=loadablesdir 2>/dev/null)" "/usr/lib/bash" "/lib/bash" "/lib64/bash" "/usr/local/lib/bash" "/usr/local/lib64/bash" + do + [ -z "${bash_modules_path}" -o ! -d "${bash_modules_path}" ] && continue + + # check for sleep + for bash_module_sleep in "sleep" "sleep.so" + do + if [ -f "${bash_modules_path}/${bash_module_sleep}" ] + then + if enable -f "${bash_modules_path}/${bash_module_sleep}" sleep 2>/dev/null + then + mysleep="mysleep_builtin" + # echo >&2 "$0: Using bash loadable ${bash_modules_path}/${bash_module_sleep} for sleep" + break + fi + fi + + done + + [ ! -z "${mysleep}" ] && break + done +fi + +# ----------------------------------------------------------------------------- +# fallback to external sleep + +[ -z "${mysleep}" ] && mysleep="sleep" + + +# ----------------------------------------------------------------------------- +# 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 + + # $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 |