but notice, none of the retries ever went past the first retry, which is good. I would test the intervals at higher lengths such as 50 75 and 100. you should see alot less retries. The cool thing is, all the touch command is doing is date and time stamping the file
. This doesn't actually halt the already sensitive router system like usleep does.
I really do hope it winds up helping someone on here although my intentions were just to bloviate (gotta love @dave14305 vernacular).
I understand it's a relatively cheap operation and developers wouldn't worry too much about it but why so many in the same second, esp. this one:
nvram get http_username#!/bin/sh
# ATTENTION: Install the timeout addon before running this!!!
# opkg install coreutils-timeout
# copy original nvram executable to /tmp
cp /bin/nvram /tmp/_nvram
# create nvram wrapper that calls original nvram executable in /tmp
cat << 'EOF' > /tmp/nvram
#!/bin/sh
#set -x # comment/uncomment to disable/enable debug mode
# required for serialization when reentry is possible
LOCK="/tmp/$(basename $0).lock"
acquire_lock() { until mkdir $LOCK &>/dev/null; do sleep 2; done; }
release_lock() { rmdir $LOCK &>/dev/null; }
#usleep 500
# one instance at a time
acquire_lock
# catch premature exit and cleanup
trap 'release_lock; exit 1' SIGHUP SIGINT SIGTERM
# make the new function accessible
#export PATH=/opt/bin:/opt/sbin:$PATH
# clear rc variable
rc=""
# keep count of total session usage
if [ ! -f "/tmp/nvramuse" ]; then
echo 0 > /tmp/nvramuse
fi
usecount=$(cat /tmp/nvramuse)
usecount=$(( usecount + 1 ))
echo $usecount > /tmp/nvramuse
# execute the nvram command
timeout 1 /tmp/_nvram $@
rc=$?
# debug messages, disable for normal use
#echo "$rc" >> /tmp/nvram.log
logger -t "nvram-override" "Executed nvram $@, use count: $usecount, exit status: $rc"
MAXCOUNT="3"
i="1"
while [ "$rc" != "0" ] && [ "$i" -le "$MAXCOUNT" ]; do
# give the device time to recover from the read failure
usleep 1000
#$(echo "$rc") >> /tmp/nvram.log
# keep count of session errors
errcount=0
if [ ! -f "/tmp/nvramerr" ]; then
echo 0 > /tmp/nvramerr
else
errcount=$(cat /tmp/nvramerr)
fi
errcount=$(( errcount + 1 ))
echo $errcount > /tmp/nvramerr
# report the error
logger -t "nvram-override" "Error detected at use count: $usecount, error count: $errcount"
logger -t "nvram-override" "Couldn't execute nvram $@, exit status: $rc (124=timeout)"
# try nvram again
timeout 1 /tmp/_nvram $@
rc=$?
logger -t "nvram-override" "Retried executing nvram $@, attempt ${i}/${MAXCOUNT}, exit status: $rc"
i="$((i+1))"
done
# any concurrent instance(s) may now run
release_lock
exit $rc
EOF
chmod +x /tmp/nvram
# replace nvram in /usr/sbin w/ nvram wrapper in /tmp
mount -o bind /tmp/nvram /bin/nvram#!/bin/sh
# ATTENTION: Install the timeout addon before running this!!!
# opkg install coreutils-timeout
# copy original wl executable to /tmp
cp /usr/sbin/wl /tmp/_wl
# create wl wrapper that calls original wl executable in /tmp
cat << 'EOF' > /tmp/wl
#!/bin/sh
#set -x # comment/uncomment to disable/enable debug mode
# required for serialization when reentry is possible
LOCK="/tmp/$(basename $0).lock"
acquire_lock() { until mkdir $LOCK &>/dev/null; do sleep 2; done; }
release_lock() { rmdir $LOCK &>/dev/null; }
#usleep 500
# one instance at a time
acquire_lock
# catch premature exit and cleanup
trap 'release_lock; exit 1' SIGHUP SIGINT SIGTERM
# make the new function accessible
#export PATH=/opt/bin:/opt/sbin:$PATH
# clear rc variable
rc=""
# keep count of total session usage
if [ ! -f "/tmp/wluse" ]; then
echo 0 > /tmp/wluse
fi
usecount=$(cat /tmp/wluse)
usecount=$(( usecount + 1 ))
echo $usecount > /tmp/wluse
# execute the wl command
timeout 1 /tmp/_wl $@
rc=$?
# debug messages, disable for normal use
#echo "$rc" >> /tmp/wl.log
logger -t "wl-override" "Executed wl $@, use count: $usecount, exit status: $rc"
MAXCOUNT="3"
i="1"
while [ "$rc" != "0" ] && [ "$i" -le "$MAXCOUNT" ]; do
# give the device time to recover from the read failure
usleep 1000
#$(echo "$rc") >> /tmp/wl.log
# keep count of session errors
errcount=0
if [ ! -f "/tmp/wlerr" ]; then
echo 0 > /tmp/wlerr
else
errcount=$(cat /tmp/wlerr)
fi
errcount=$(( errcount + 1 ))
echo $errcount > /tmp/wlerr
# report the error
logger -t "wl-override" "Error detected at use count: $usecount, error count: $errcount"
logger -t "wl-override" "Couldn't execute wl $@, exit status: $rc (124=timeout)"
# try wl again
timeout 1 /tmp/_wl $@
rc=$?
logger -t "wl-override" "Retried executing wl $@, attempt ${i}/${MAXCOUNT}, exit status: $rc"
i="$((i+1))"
done
# any concurrent instance(s) may now run
release_lock
exit $rc
EOF
chmod +x /tmp/wl
# replace wl in /usr/sbin w/ wl wrapper in /tmp
mount -o bind /tmp/wl /usr/sbin/wlnvram.sh and wl.sh.umount /bin/nvram - to deactivate nvram wrapperumount /usr/sbin/wl - to deactivate wl wrapper
nvram wrapper
#!/bin/sh
# copy original nvram executable to /tmp
cp /bin/nvram /tmp/_nvram
# create nvram wrapper that calls original nvram executable in /tmp
cat << 'EOF' > /tmp/nvram
#!/bin/sh
#set -x # comment/uncomment to disable/enable debug mode
# required for serialization when reentry is possible
LOCK="/tmp/$(basename "$0").lock"
acquire_lock() { until mkdir "$LOCK" &>/dev/null; do touch /tmp/nvram; done; }
release_lock() { rmdir "$LOCK" &>/dev/null; }
# one instance at a time
acquire_lock
# catch premature exit and cleanup
trap 'release_lock; exit 1' SIGHUP SIGINT SIGTERM
# make the new function accessible
#export PATH=/opt/bin:/opt/sbin:$PATH
# clear rc variable
rc=""
# keep count of total session usage
if [ ! -f "/tmp/nvramuse" ]; then
echo 0 > /tmp/nvramuse
fi
usecount=$(cat /tmp/nvramuse)
usecount=$((usecount + 1 ))
echo $usecount > /tmp/nvramuse
#INTERVAL="100"
MAXCOUNT="3"
run_cmd () {
local to
local start
local child
# here as the interval number increases, the longer we wait.
to="$1"
to="$((to*INTERVAL))"; shift
$@ & local child="$!" start=0
touch /tmp/nvram
while { [ "$(kill -0 $child >/dev/null 2>&1; printf "%s" "$?")" = "0" ] && [ "$start" -le "$to" ]; }; do
# to account for killing too soon, as the number of tries required increases our count requirement increases before we attempt to kill the process.
touch /tmp/nvram
start="$((start+1))"
if [ $start -gt $to ]; then
kill -s 9 $child 2>/dev/null
wait $child
return 1
fi
done
return 0
}
for INTERVAL in 25 50 75 100; do
# make the new function accessible, on the first run we want to exit right away if successful.
i="1"
if { run_cmd "$i" /tmp/_nvram "$@"; }; then
rc="0"
else
rc="1"
fi
logger -t "nvram-override" "Executed nvram $@ (at $INTERVAL), use count: $usecount, exit status: $rc"
# here we add an interval check and allow up to 3 retries.
while [ "$i" -le "$MAXCOUNT" ] && [ "$rc" != "0" ]; do
touch /tmp/nvram
if { run_cmd "$i" /tmp/_nvram "$@"; }; then
rc="0"
else
rc="1"
errcount="$rc"
if [ ! -f "/tmp/nvramerr" ]; then
echo 0 > /tmp/nvramerr
else
errcount=$(cat /tmp/nvramerr)
fi
errcount=$((errcount + 1 ))
echo $errcount > /tmp/nvramerr
logger -t "nvram-override" "Error detected at use count: $usecount (at $INTERVAL), error count: $errcount"
logger -t "nvram-override" "Couldn't execute nvram $@ (at $INTERVAL) , exit status: $rc (124=timeout)"
fi
logger -t "nvram-override" "Retried executing nvram $@ (at $INTERVAL), attempt ${i}/${MAXCOUNT}, exit status: $rc"
i="$((i+1))"
done
[ "$rc" = "0" ] && break || logger -t "nvram-override" "NVRAM remained locked too long; continuing anyway."
done
# any concurrent instance(s) may now run
release_lock
exit $rc
EOF
chmod +x /tmp/nvram
# replace nvram in /usr/sbin w/ nvram wrapper in /tmp
mount -o bind /tmp/nvram /bin/nvram#!/bin/sh
# copy original wl executable to /tmp
cp /usr/sbin/wl /tmp/_wl
# create wl wrapper that calls original wl executable in /tmp
cat << 'EOF' > /tmp/wl
#!/bin/sh
#set -x # comment/uncomment to disable/enable debug mode
# required for serialization when reentry is possible
LOCK="/tmp/$(basename "$0").lock"
acquire_lock() { until mkdir "$LOCK" &>/dev/null; do touch /tmp/wl; done; }
release_lock() { rmdir "$LOCK" &>/dev/null; }
# one instance at a time
acquire_lock
# catch premature exit and cleanup
trap 'release_lock; exit 1' SIGHUP SIGINT SIGTERM
# make the new function accessible
#export PATH=/opt/bin:/opt/sbin:$PATH
# clear rc variable
rc=""
# keep count of total session usage
if [ ! -f "/tmp/wluse" ]; then
echo 0 > /tmp/wluse
fi
usecount=$(cat /tmp/wluse)
usecount=$((usecount + 1 ))
echo $usecount > /tmp/wluse
#INTERVAL="100"
MAXCOUNT="3"
run_cmd () {
local to
local start
local child
# here as the interval number increases, the longer we wait..
to="$1"
to="$((to*INTERVAL))"; shift
$@ & local child="$!" start=0
touch /tmp/wl
while { [ "$(kill -0 $child >/dev/null 2>&1; printf "%s" "$?")" = "0" ] && [ "$start" -le "$to" ]; }; do
# to account for killing too soon, as the number of tries required increases our count requirement increases before we attempt to kill the process.
touch /tmp/wl
start="$((start+1))"
if [ $start -gt $to ]; then
kill -s 9 $child 2>/dev/null
wait $child
return 1
fi
done
return 0
}
for INTERVAL in 25 50 75 100; do
# make the new function accessible, on the first run we want to exit right away if successful.
i="1"
if { run_cmd "$i" /tmp/_wl "$@"; }; then
rc="0"
else
rc="1"
fi
logger -t "wl-override" "Executed wl $@ (at $INTERVAL), use count: $usecount, exit status: $rc"
# here we add an interval check and allow up to 3 retries.
while [ "$i" -le "$MAXCOUNT" ] && [ "$rc" != "0" ]; do
touch /tmp/wl
if { run_cmd "$i" /tmp/_wl "$@"; }; then
rc="0"
else
rc="1"
errcount="$rc"
if [ ! -f "/tmp/wlerr" ]; then
echo 0 > /tmp/wlerr
else
errcount=$(cat /tmp/wlerr)
fi
errcount=$((errcount + 1 ))
echo $errcount > /tmp/wlerr
logger -t "wl-override" "Error detected at use count: $usecount (at $INTERVAL), error count: $errcount"
logger -t "wl-override" "Couldn't execute wl $@ (at $INTERVAL), exit status: $rc (124=timeout)"
fi
logger -t "wl-override" "Retried executing wl $@ (at $INTERVAL), attempt ${i}/${MAXCOUNT}, exit status: $rc"
i="$((i+1))"
done
[ "$rc" = "0" ] && break || logger -t "wl-override" "wl remained locked too long; continuing anyway."
done
# any concurrent instance(s) may now run
release_lock
exit $rc
EOF
chmod +x /tmp/wl
# replace wl in /usr/sbin w/ wl wrapper in /tmp
mount -o bind /tmp/wl /usr/sbin/wlfor INTERVAL in 25 50 75 100; do...
The interval is actually there if we need a longer time before we kill the process.
Hey oracle, you are welcome. If you decide to fire up my current one using your plugged in statics feel free to share what they look like. I remember what yours looked like with the timeout. it was quite interesting. I want to see how many retries and what not.
logger -t "nvram-override" "Executed nvram $@, use count: $usecount, exit status: $rc"
#!/bin/sh
# copy original nvram executable to /tmp
cp /bin/nvram /tmp/_nvram
# create nvram wrapper that calls original nvram executable in /tmp
cat << 'EOF' > /tmp/nvram
#!/bin/sh
#set -x # comment/uncomment to disable/enable debug mode
# required for serialization when reentry is possible
LOCK="/tmp/$(basename "$0").lock"
acquire_lock() { until mkdir "$LOCK" &>/dev/null; do touch /tmp/nvram; done; }
release_lock() { rmdir "$LOCK" &>/dev/null; }
# one instance at a time
acquire_lock
# catch premature exit and cleanup
trap 'release_lock; exit 1' SIGHUP SIGINT SIGTERM
# make the new function accessible
#export PATH=/opt/bin:/opt/sbin:$PATH
# clear rc variable
rc=""
# keep count of total session usage
if [ ! -f "/tmp/nvramuse" ]; then
echo 0 > /tmp/nvramuse
fi
usecount=$(cat /tmp/nvramuse)
usecount=$((usecount + 1 ))
echo $usecount > /tmp/nvramuse
#INTERVAL="100"
MAXCOUNT="3"
run_cmd () {
local to
local start
local child
# here as the interval number increases, the longer we wait.
to="$1"
to="$((to*INTERVAL))"; shift
$@ & local child="$!" start=0
touch /tmp/nvram
while { [ "$(kill -0 $child >/dev/null 2>&1; printf "%s" "$?")" = "0" ] && [ "$start" -le "$to" ]; }; do
# to account for killing too soon, as the number of tries required increases our count requirement increases before we attempt to kill the process.
touch /tmp/nvram
start="$((start+1))"
if [ $start -gt $to ]; then
kill -s 9 $child 2>/dev/null
wait $child
return 1
fi
done
return 0
}
for INTERVAL in 5 10 20; do
# make the new function accessible, on the first run we want to exit right away if successful.
i="1"
if { run_cmd "$i" /tmp/_nvram "$@"; }; then
rc="0"
else
rc="1"
fi
logger -t "nvram-override" "Executed nvram $@ (at $INTERVAL), use count: $usecount, exit status: $rc"
# here we add an interval check and allow up to 3 retries.
while [ "$i" -le "$MAXCOUNT" ] && [ "$rc" != "0" ]; do
touch /tmp/nvram
if { run_cmd "$i" /tmp/_nvram "$@"; }; then
rc="0"
else
rc="1"
errcount="$rc"
if [ ! -f "/tmp/nvramerr" ]; then
echo 0 > /tmp/nvramerr
else
errcount=$(cat /tmp/nvramerr)
fi
errcount=$((errcount + 1 ))
echo $errcount > /tmp/nvramerr
logger -t "nvram-override" "Error detected at use count: $usecount (at $INTERVAL), error count: $errcount"
logger -t "nvram-override" "Couldn't execute nvram $@ (at $INTERVAL) , exit status: $rc (124=timeout)"
fi
logger -t "nvram-override" "Retried executing nvram $@ (at $INTERVAL), attempt ${i}/${MAXCOUNT}, exit status: $rc"
i="$((i+1))"
done
[ "$rc" = "0" ] && break || logger -t "nvram-override" "NVRAM remained locked too long; continuing anyway."
done
# any concurrent instance(s) may now run
release_lock
exit $rc
EOF
chmod +x /tmp/nvram
# replace nvram in /usr/sbin w/ nvram wrapper in /tmp
mount -o bind /tmp/nvram /bin/nvram@Oracle I cannot "truely" test it to the extent you can. The only difficulty I faced was I had to "force failures" to make the script work since I do not posess a RT-AC86U with this issue.@SomeWhereOverTheRainBow I guess I'll answer tomorrow about the intervals.
Meantime the guesthouse is open for feedback from other users.
Does this work for you, did you try using the wrappers, did you face any difficulty?
Running time appears unaffected: 5:07 min per 3000 loop iterations.
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