Merge tag 'upstream/1.4.0+dfsg'

Upstream version 1.4.0+dfsg

1 files changed, 137 insertions, 38 deletions

diff --git a/plugins.d/loopsleepms.sh.inc b/plugins.d/loopsleepms.sh.inc
index 02ab694d2..6de93043c 100644
--- a/plugins.d/loopsleepms.sh.inc
+++ b/plugins.d/loopsleepms.sh.inc
@@ -1,10 +1,5 @@
 # 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="$(which date)"
 if [ -z "$LOOPSLEEP_DATE" ]
     then
@@ -12,17 +7,14 @@ if [ -z "$LOOPSLEEP_DATE" ]
     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
-
-now_ms=
-current_time_ms() {
-    # if high resolution is not supported
-    # just sleep the time requested, in seconds
+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"
@@ -31,60 +23,167 @@ current_time_ms() {
     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 "$0: Invalid setup for current_time_ms_from_uptime() - falling back to current_time_ms_from_date()."
+    current_time_ms="current_time_ms_from_date"
+    current_time_ms_accuracy=1
+fi
+
+# -----------------------------------------------------------------------------
+# use read with timeout for sleep
+
+mysleep="mysleep_read"
+
+mysleep_fifo="${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="$1" div s m now mstosleep
+    local tellwork=0 t="${1}" div s m now mstosleep
 
-    if [ "$t" = "tellwork" ]
+    if [ "${t}" = "tellwork" ]
     then
         tellwork=1
         shift
-        t="$1"
+        t="${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 ]
+    if [ ${LOOPSLEEPMS_HIGHRES} -eq 0 ]
     then
-        sleep $t
+        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
+    # get the current time, in ms in ${now_ms}
+    ${current_time_ms}
 
     # calculate ms since last run
-    LOOPSLEEPMS_LASTWORK=$((now - LOOPSLEEPMS_LASTRUN - LOOPSLEEPMS_LASTSLEEP))
+    [ ${LOOPSLEEPMS_LASTRUN} -gt 0 ] && \
+        LOOPSLEEPMS_LASTWORK=$((now_ms - LOOPSLEEPMS_LASTRUN - LOOPSLEEPMS_LASTSLEEP))
     # 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=$(( t - LOOPSLEEPMS_LASTWORK ))
+    mstosleep=$(( 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
+    test ${mstosleep} -lt 200 && mstosleep=200
 
-    s=$((mstosleep / 1000))
-    m=$((mstosleep - (s * 1000)))
+    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"
+    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 "# sleeping ${s}.${m}"
     # echo
-    sleep $s.$m
+    ${mysleep} ${s}.${m}
 
     # keep the values we need
     # for our next run
-    LOOPSLEEPMS_LASTRUN=$now
     LOOPSLEEPMS_LASTSLEEP=$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