Fix logpersist.stop race condition
The steps did by `logpersist.stop --clear` is
1. setprop logd.logpersistd clear
2. setprop logd.logpersistd.size ""
3. wait logd.logpersistd changed to be empty by logcated.rc
The problem is, logpersist.stop may modify size earlier than located.rc invoking logcat.
See comment 5 in the bug for detailed reproduce steps.
Bug: b/275518567
Test: `logpersist.stop --clear` should delete all log files in /data/misc/logd
Change-Id: Ifacfacc6486c2b98a67fb7d9587e6f588b84f179
diff --git a/logcat/logpersist b/logcat/logpersist
index 7a41ab1..31b4c74 100755
--- a/logcat/logpersist
+++ b/logcat/logpersist
@@ -2,6 +2,16 @@
# logpersist cat, start and stop handlers
progname="${0##*/}"
+function setprop_and_wait_for_change() {
+ local name="$1"
+ local value="$2"
+
+ setprop "${name}" "${value}"
+ while [ "${value}" = "${getprop ${name}}" ]; do
+ sleep 0.1
+ done
+}
+
property=persist.logd.logpersistd
case `getprop ${property#persist.}.enable` in
@@ -81,7 +91,7 @@
current_size="`getprop ${property#persist.}.size`"
if [ "${service}" = "`getprop ${property#persist.}`" ]; then
if [ "true" = "${clear}" ]; then
- setprop ${property#persist.} "clear"
+ setprop_and_wait_for_change ${property#persist.} "clear"
elif [ "${buffer}|${size}" != "${current_buffer}|${current_size}" ]; then
echo "ERROR: Changing existing collection parameters from" >&2
if [ "${buffer}" != "${current_buffer}" ]; then
@@ -104,7 +114,7 @@
exit 1
fi
elif [ "true" = "${clear}" ]; then
- setprop ${property#persist.} "clear"
+ setprop_and_wait_for_change ${property#persist.} "clear"
fi
if [ -n "${buffer}${current_buffer}" ]; then
setprop ${property}.buffer "${buffer}"
@@ -120,9 +130,6 @@
setprop ${property#persist.}.size ""
fi
fi
- while [ "clear" = "`getprop ${property#persist.}`" ]; do
- continue
- done
# Tell Settings that we are back on again if we turned logging off
tag="${log_tag#Settings}"
if [ X"${log_tag}" != X"${tag}" ]; then
@@ -142,7 +149,7 @@
echo "WARNING: Can not use --size or --buffer with ${progname%.*}.stop" >&2
fi
if [ "true" = "${clear}" ]; then
- setprop ${property#persist.} "clear"
+ setprop_and_wait_for_change ${property#persist.} "clear"
else
setprop ${property#persist.} "stop"
fi
@@ -156,9 +163,6 @@
# deal with trampoline for empty properties
setprop ${property#persist.}.size ""
fi
- while [ "clear" = "`getprop ${property#persist.}`" ]; do
- continue
- done
;;
*)
echo "ERROR: Unexpected command ${0##*/} ${args}" >&2
