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authorFederico Ceratto <federico.ceratto@gmail.com>2016-03-30 21:40:42 +0000
committerFederico Ceratto <federico.ceratto@gmail.com>2016-03-30 21:40:42 +0000
commit9ce153ce7167c11adba8ac225edc7a707e97c6eb (patch)
tree9f6e849cce2dcc7e5b4e9e6252c843dc2d0787a2 /plugins.d/loopsleepms.sh.inc
downloadnetdata-9ce153ce7167c11adba8ac225edc7a707e97c6eb.tar.xz
netdata-9ce153ce7167c11adba8ac225edc7a707e97c6eb.zip
Imported Upstream version 1.0.0upstream/1.0.0
Diffstat (limited to 'plugins.d/loopsleepms.sh.inc')
-rw-r--r--plugins.d/loopsleepms.sh.inc90
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
+}