5e001776f4
--wrap flag in logcat translates directly to the mTimeout inside logd, the value set is ANDROID_LOG_WRAP_DEFAULT_TIMEOUT defined in <log/log_read.h> as 7200 or 2 hours. For a non blocking read with a selected timeout, the logger waits until either the log buffer is about to 'wrap' and prune the log entry, or at the specified timeout. Non blocking in the logger context means that when there are no more log entries, the socket is closed. clock_gettime(CLOCK_REALTIME) is UTC 1970 epoch *NIX time. Is only affected for time updates, not timezone or daylight savings time. If there is a large user initiated time change, both the log entries and the timeout mentioned above really get called into question, so we trigger a release of the logs for clarity. This is so that the log reader can handle the disruptively updated time, and can immediately check the local time if necessary. The logger has a 5 second window for entries to land in time sorted order into the logging list. This should offer the log reader some differentiation between logging order sequence for monotonically increasing time, and sequence order in the face of user initiated time adjustments that break monotonicity. This change is about major time adjustments that can cause Fear, Uncertainty or Doubt about log entries. By returning, immediate action can be taken, rather than having to comb through the logs with less details about the time disruptions in hand. The least it can do is record what we have, and restart the call with a new tail time and timeout. Test: gTest liblog-unit-tests logcat-unit-test logd-unit-tests Bug: 35373582 Change-Id: I92cac83be99d68634ffd4ebd2f3a3067cfd0e942 |
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.. | ||
tests | ||
.clang-format | ||
Android.mk | ||
CommandListener.cpp | ||
CommandListener.h | ||
event.logtags | ||
FlushCommand.cpp | ||
FlushCommand.h | ||
libaudit.c | ||
libaudit.h | ||
LogAudit.cpp | ||
LogAudit.h | ||
LogBuffer.cpp | ||
LogBuffer.h | ||
LogBufferElement.cpp | ||
LogBufferElement.h | ||
LogCommand.cpp | ||
LogCommand.h | ||
logd.rc | ||
LogKlog.cpp | ||
LogKlog.h | ||
LogListener.cpp | ||
LogListener.h | ||
LogReader.cpp | ||
LogReader.h | ||
LogStatistics.cpp | ||
LogStatistics.h | ||
logtagd.rc | ||
LogTags.cpp | ||
LogTags.h | ||
LogTimes.cpp | ||
LogTimes.h | ||
LogUtils.h | ||
LogWhiteBlackList.cpp | ||
LogWhiteBlackList.h | ||
main.cpp | ||
README.auditd | ||
README.property |
The properties that logd and friends react to are: name type default description ro.logd.auditd bool true Enable selinux audit daemon ro.logd.auditd.dmesg bool true selinux audit messages sent to dmesg. ro.logd.auditd.main bool true selinux audit messages sent to main. ro.logd.auditd.events bool true selinux audit messages sent to events. persist.logd.security bool false Enable security buffer. ro.device_owner bool false Override persist.logd.security to false ro.logd.kernel bool+ svelte+ Enable klogd daemon ro.logd.statistics bool+ svelte+ Enable logcat -S statistics. ro.debuggable number if not "1", logd.statistics & ro.logd.kernel default false. logd.logpersistd.enable bool auto Safe to start logpersist daemon service logd.logpersistd string persist Enable logpersist daemon, "logcatd" turns on logcat -f in logd context. Responds to logcatd, clear and stop. logd.logpersistd.buffer persist logpersistd buffers to collect logd.logpersistd.size persist logpersistd size in MB persist.logd.logpersistd string Enable logpersist daemon, "logcatd" turns on logcat -f in logd context. persist.logd.logpersistd.buffer all logpersistd buffers to collect persist.logd.logpersistd.size 256 logpersistd size in MB persist.logd.size number ro Global default size of the buffer for all log ids at initial startup, at runtime use: logcat -b all -G <value> ro.logd.size number svelte default for persist.logd.size. Larger platform default sizes than 256KB are known to not scale well under log spam pressure. Address the spam first, resist increasing the log buffer. persist.logd.size.<buffer> number ro Size of the buffer for <buffer> log ro.logd.size.<buffer> number svelte default for persist.logd.size.<buffer> ro.config.low_ram bool false if true, logd.statistics, logd.kernel default false, logd.size 64K instead of 256K. persist.logd.filter string Pruning filter to optimize content. At runtime use: logcat -P "<string>" ro.logd.filter string "~! ~1000/!" default for persist.logd.filter. This default means to prune the oldest entries of chattiest UID, and the chattiest PID of system (1000, or AID_SYSTEM). persist.logd.timestamp string ro The recording timestamp source. "m[onotonic]" is the only supported key character, otherwise realtime. ro.logd.timestamp string realtime default for persist.logd.timestamp log.tag string persist The global logging level, VERBOSE, DEBUG, INFO, WARN, ERROR, ASSERT or SILENT. Only the first character is the key character. persist.log.tag string build default for log.tag log.tag.<tag> string persist The <tag> specific logging level. persist.log.tag.<tag> string build default for log.tag.<tag> NB: - auto - managed by /init - bool+ - "true", "false" and comma separated list of "eng" (forced false if ro.debuggable is not "1") or "svelte" (forced false if ro.config.low_ram is true). - svelte - see ro.config.low_ram for details. - svelte+ - see ro.config.low_ram and ro.debuggable for details. - ro - <base property> temporary override, ro.<base property> platform default. - persist - <base property> override, persist.<base property> platform default. - build - VERBOSE for native, DEBUG for jvm isLoggable, or developer option. - number - support multipliers (K or M) for convenience. Range is limited to between 64K and 256M for log buffer sizes. Individual log buffer ids such as main, system, ... override global default. - Pruning filter is of form of a space-separated list of [~][UID][/PID] references, where '~' prefix means to blacklist otherwise whitelist. For blacklisting, UID or PID may be a '!' to instead reference the chattiest client, with the restriction that the PID must be in the UID group 1000 (system or AID_SYSTEM).