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-rw-r--r--collectors/charts.d.plugin/loopsleepms.sh.inc227
1 files changed, 227 insertions, 0 deletions
diff --git a/collectors/charts.d.plugin/loopsleepms.sh.inc b/collectors/charts.d.plugin/loopsleepms.sh.inc
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+# 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
+
+# macOS 'date' doesnt support '%N' precision
+# echo $(/bin/date +"%N") is "N"
+if [ "$($LOOPSLEEP_DATE +"%N")" = "N" ]; then
+ LOOPSLEEP_DATE_FORMAT="%s * 1000"
+else
+ LOOPSLEEP_DATE_FORMAT="%s * 1000 + 10#%-N / 1000000"
+fi
+
+now_ms=
+LOOPSLEEPMS_HIGHRES=1
+test "$($LOOPSLEEP_DATE +%N)" = "%N" && LOOPSLEEPMS_HIGHRES=0
+test -z "$($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 +"$LOOPSLEEP_DATE_FORMAT")))"
+ fi
+}
+
+# -----------------------------------------------------------------------------
+# use /proc/uptime as a high resolution timer
+
+current_time_ms_from_date
+current_time_ms_from_uptime_started="${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