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/LogTimes.h b/logd/LogTimes.h
old mode 100644
new mode 100755
index 9ca2aea..76d016c
--- a/logd/LogTimes.h
+++ b/logd/LogTimes.h
@@ -26,6 +26,8 @@
#include <log/log.h>
#include <sysutils/SocketClient.h>
+typedef unsigned int log_mask_t;
+
class LogReader;
class LogBufferElement;
@@ -41,7 +43,7 @@
LogReader& mReader;
static void* threadStart(void* me);
static void threadStop(void* me);
- const unsigned int mLogMask;
+ const log_mask_t mLogMask;
const pid_t mPid;
unsigned int skipAhead[LOG_ID_MAX];
pid_t mLastTid[LOG_ID_MAX];
@@ -51,7 +53,7 @@
public:
LogTimeEntry(LogReader& reader, SocketClient* client, bool nonBlock,
- unsigned long tail, unsigned int logMask, pid_t pid,
+ unsigned long tail, log_mask_t logMask, pid_t pid,
log_time start, uint64_t timeout);
SocketClient* mClient;
@@ -133,8 +135,11 @@
// No one else is holding a reference to this
delete this;
}
- bool isWatching(log_id_t id) {
- return (mLogMask & (1 << id)) != 0;
+ bool isWatching(log_id_t id) const {
+ return mLogMask & (1 << id);
+ }
+ bool isWatchingMultiple(log_mask_t logMask) const {
+ return mLogMask & logMask;
}
// flushTo filter callbacks
static int FilterFirstPass(const LogBufferElement* element, void* me);