blob: 6de93043c93a5e6823bbfc2aced0fcb69ec0224d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
# no need for shebang - this file is included from other scripts
LOOPSLEEP_DATE="$(which date)"
if [ -z "$LOOPSLEEP_DATE" ]
then
echo >&2 "$0: ERROR: Cannot find the command 'date' in the system path."
exit 1
fi
# -----------------------------------------------------------------------------
# use the date command as a high resolution timer
now_ms=
LOOPSLEEPMS_HIGHRES=1
test "$($LOOPSLEEP_DATE +%N)" = "%N" && LOOPSLEEPMS_HIGHRES=0
test -z "$($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 "$0: Invalid setup for current_time_ms_from_uptime() - falling back to current_time_ms_from_date()."
current_time_ms="current_time_ms_from_date"
current_time_ms_accuracy=1
fi
# -----------------------------------------------------------------------------
# use read with timeout for sleep
mysleep="mysleep_read"
mysleep_fifo="${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
# $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))
# 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
|
