logd: enhance multiple blocking readers performance
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
diff --git a/logd/FlushCommand.h b/logd/FlushCommand.h
old mode 100644
new mode 100755
index 7cdd03f..543dfc3
--- a/logd/FlushCommand.h
+++ b/logd/FlushCommand.h
@@ -29,16 +29,36 @@
LogReader& mReader;
bool mNonBlock;
unsigned long mTail;
- unsigned int mLogMask;
+ log_mask_t mLogMask;
pid_t mPid;
log_time mStart;
uint64_t mTimeout;
public:
- explicit FlushCommand(LogReader& mReader, bool nonBlock = false,
- unsigned long tail = -1, unsigned int logMask = -1,
- pid_t pid = 0, log_time start = log_time::EPOCH,
- uint64_t timeout = 0);
+ // for opening a reader
+ explicit FlushCommand(LogReader& reader, bool nonBlock, unsigned long tail,
+ log_mask_t logMask, pid_t pid, log_time start,
+ uint64_t timeout)
+ : mReader(reader),
+ mNonBlock(nonBlock),
+ mTail(tail),
+ mLogMask(logMask),
+ mPid(pid),
+ mStart(start),
+ mTimeout((start != log_time::EPOCH) ? timeout : 0) {
+ }
+
+ // for notification of an update
+ explicit FlushCommand(LogReader& reader, log_mask_t logMask)
+ : mReader(reader),
+ mNonBlock(false),
+ mTail(-1),
+ mLogMask(logMask),
+ mPid(0),
+ mStart(log_time::EPOCH),
+ mTimeout(0) {
+ }
+
virtual void runSocketCommand(SocketClient* client);
static bool hasReadLogs(SocketClient* client);