logd: reader/writer element locks
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
diff --git a/logd/FlushCommand.cpp b/logd/FlushCommand.cpp
index c67d2bf..a9edc3e 100644
--- a/logd/FlushCommand.cpp
+++ b/logd/FlushCommand.cpp
@@ -44,14 +44,14 @@
// LogTimeEntrys, and spawn a transitory per-client thread to
// work at filing data to the socket.
//
-// global LogTimeEntry::lock() is used to protect access,
+// global LogTimeEntry::wrlock() is used to protect access,
// reference counts are used to ensure that individual
// LogTimeEntry lifetime is managed when not protected.
void FlushCommand::runSocketCommand(SocketClient* client) {
LogTimeEntry* entry = NULL;
LastLogTimes& times = mReader.logbuf().mTimes;
- LogTimeEntry::lock();
+ LogTimeEntry::wrlock();
LastLogTimes::iterator it = times.begin();
while (it != times.end()) {
entry = (*it);