NBLog periodic merging thread
Bug: 35468674
Test: no change in functionality, everything works as before
Change-Id: Id2cea243bc15767ca6803c9505bf23a18411500e
diff --git a/media/libnbaio/include/NBLog.h b/media/libnbaio/include/NBLog.h
index 043f15e..369c22a 100644
--- a/media/libnbaio/include/NBLog.h
+++ b/media/libnbaio/include/NBLog.h
@@ -20,8 +20,9 @@
#define ANDROID_MEDIA_NBLOG_H
#include <binder/IMemory.h>
-#include <utils/Mutex.h>
#include <audio_utils/fifo.h>
+#include <utils/Mutex.h>
+#include <utils/threads.h>
#include <vector>
@@ -41,6 +42,7 @@
enum Event {
EVENT_RESERVED,
EVENT_STRING, // ASCII string, not NUL-terminated
+ // TODO: make timestamp optional
EVENT_TIMESTAMP, // clock_gettime(CLOCK_MONOTONIC)
EVENT_INTEGER, // integer value entry
EVENT_FLOAT, // floating point value entry
@@ -106,7 +108,7 @@
template<typename T>
inline const T& payload() {
- return *reinterpret_cast<const T *>(ptr + 2);
+ return *reinterpret_cast<const T *>(ptr + offsetof(entry, data));
}
private:
@@ -425,6 +427,43 @@
size_t handleAuthor(const FormatEntry &fmtEntry, String8 *body);
};
+// MergeThread is a thread that contains a Merger. It works as a retriggerable one-shot:
+// when triggered, it awakes for a lapse of time, during which it periodically merges; if
+// retriggered, the timeout is reset.
+// The thread is triggered on AudioFlinger binder activity.
+class MergeThread : public Thread {
+public:
+ MergeThread(Merger &merger);
+ virtual ~MergeThread() override;
+
+ // Reset timeout and activate thread to merge periodically if it's idle
+ void wakeup();
+
+ // Set timeout period until the merging thread goes idle again
+ void setTimeoutUs(int time);
+
+private:
+ virtual bool threadLoop() override;
+
+ // the merger who actually does the work of merging the logs
+ Merger& mMerger;
+
+ // mutex for the condition variable
+ Mutex mMutex;
+
+ // condition variable to activate merging on timeout >= 0
+ Condition mCond;
+
+ // time left until the thread blocks again (in microseconds)
+ int mTimeoutUs;
+
+ // merging period when the thread is awake
+ static const int kThreadSleepPeriodUs = 1000000 /*1s*/;
+
+ // initial timeout value when triggered
+ static const int kThreadWakeupPeriodUs = 3000000 /*3s*/;
+};
+
}; // class NBLog
} // namespace android