logd suffers performance degradation when multiple blocking
readers connect to it. Each time when the writer thread log
new entries, all of the readers are notified regardless of
which log id they are watching.
In this case, only give notification to the readers who are
actually watching new entries' log id. This decreases logd
CPU consumption by skipping unnecessary LogBuffer::flushTo
loops.
Test: liblog-unit-tests, logd-unit-tests & CtsLiblogTestCases
logcat-unit-tests
Test: manual:
1.'logcat –b all' at constant heavy logging load level
2.simultaneously 'logcat –b crash' in another session,
a healthy crash buffer usually keep empty
3.logd CPU consumption doesn't increase after step 2
Change-Id: I4ffc045c9feb7a0998f7e47ae2173f8f6aa28e8a
Switch to a reader writer lock for the Element List lock. Also setup
for a reader writer lock for the Times list, but continue to use a
mutex where rdlock() and wrlock() are the same implementation for now.
This should improve general reader performance and prevent blocking of
other reader operations or exit by a single hung logd.reader.per
thread. For example, a full length logcat of an empty buffer (eg:
crash log buffer) will hold a lock while the iterator scans the entire
list.
Test: gTest liblog-unit-tests, logd-unit-tests, logcat-unit-tests
Bug: 37378309
Bug: 37483775
Change-Id: If5723ff4a978e17d828a75321e8f0ba91d4a09e0
--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
Use getRealTime() instead and leverage private liblog log_time
comparison and math functions. This saves 8 bytes off each
element in the logging database.
Test: gTest liblog-unit-tests logd-unit-tests logcat-unit-tests
Bug: 35373582
Change-Id: Ia55ef8b95cbb2a841ccb1dae9a24f314735b076a
Switch _all_ file's coding style to match to ease all future changes.
SideEffects: None
Test: compile
Bug: 35373582
Change-Id: I470cb17f64fa48f14aafc02f574e296bffe3a3f3
LogReader.h needs to be individually importable.
Fix a few others, drop includes of local includes, let them be
included in source instead and allow headers to be included
alphabetically. Was not a complete audit since goal was to
separate LogReader.h out from the pack.
Bug: 27242723
Change-Id: Ic7759ef90995e5bd285810706af33550c73cf5b5
- limit AID_SYSTEM uid or gid to read security buffer messages
- adjust liblog tests to reflect the reality of this adjustment
To fully test all security buffer paths and modes
$ su 0,0,0 /data/nativetest/liblog-unit-tests/liblog-unit-tests --gtest_filter=liblog.__security*
$ su 1000,1000,1000 /data/nativetest/liblog-unit-tests/liblog-unit-tests --gtest_filter=liblog.__security*
$ su 2000,2000,2000 /data/nativetest/liblog-unit-tests/liblog-unit-tests --gtest_filter=liblog.__security*
ToDo: Integrate the above individually into the gTest Q/A testing
Bug: 26029733
Change-Id: Idcf5492db78fa6934ef6fb43f3ef861052675651
If a timeout is specified for the reader, then go to sleep
with the socket open. If the start time is about to get
pruned in the specified log buffers, then wakeup and dump
the logs; or wakeup on timeout, whichever comes first.
Bug: 25929746
Change-Id: I7d2421c2c5083b33747b84f74d9a560d3ba645df
- switch to simpler and faster internal sequence number, drops
a syscall overhead on 32-bit platforms.
- add ability to break-out of flushTo loop with filter return -1
allowing in reduction in reader overhead.
Change-Id: Ic5cb2b9afa4d9470153971fc9197b07279e2b79d
* Create a new userspace log daemon for handling logging messages.
Original-Change-Id: I75267df16359684490121e6c31cca48614d79856
Signed-off-by: Nick Kralevich <nnk@google.com>
* Merge conflicts
* rename new syslog daemon to logd to prevent confusion with bionic syslog
* replace racy getGroups call with KISS call to client->getGid()
* Timestamps are filed at logging source
* insert entries into list in timestamp order
* Added LogTimeEntry tail filtration handling
* Added region locking around LogWriter list
* separate threads for each writer
* /dev/socket/logd* permissions
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
(cherry picked from commit 3e76e0a497)
Author: Nick Kralevich <nnk@google.com>
Change-Id: Ice88b1412d8f9daa7f9119b2b5aaf684a5e28098
