Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 34ad8af0 authored by Olivier Gaillard's avatar Olivier Gaillard
Browse files

Improve binder calls stats sampling. 

- Decouple detailed tracking and sampling. Detailed tracking now control
which data wwe should track (e.g. exception, max reply size, ...),
sampling controls the % of requests to track
- Do not create a CallStat object just for the sake of tracking the call
count. Most of the keys have a really low call count (60% of keys below
10 call counts, 90% below 100 calls). When data sampling is enabled, we
can save lots of memory.

Test: unit test
Change-Id: If81b38023a76a8b1e07e655f9ecd8a098d401df4
parent c0eadf99

core/java/com/android/internal/os/BinderCallsStats.java

+29 −8
Original line number Diff line number Diff line
@@ -67,7 +67,10 @@ public class BinderCallsStats implements BinderInternal.Observer { 
    private static final int MAX_EXCEPTION_COUNT_SIZE = 50;

    private static final String EXCEPTION_COUNT_OVERFLOW_NAME = "overflow";



    // Whether to collect all the data: cpu + exceptions + reply/request sizes.

    private boolean mDetailedTracking = DETAILED_TRACKING_DEFAULT;

    // Sampling period to control how often to track CPU usage. 1 means all calls, 100 means ~1 out

    // of 100 requests.

    private int mPeriodicSamplingInterval = PERIODIC_SAMPLING_INTERVAL_DEFAULT;

    @GuardedBy("mLock")

    private final SparseArray<UidEntry> mUidEntries = new SparseArray<>();
@@ -177,7 +180,7 @@ public class BinderCallsStats implements BinderInternal.Observer { 
        s.exceptionThrown = false;

        s.cpuTimeStarted = -1;

        s.timeStarted = -1;

        if (mDetailedTracking || shouldRecordDetailedData()) {

        if (shouldRecordDetailedData()) {

            s.cpuTimeStarted = getThreadTimeMicro();

            s.timeStarted = getElapsedRealtimeMicro();

        }
@@ -224,14 +227,14 @@ public class BinderCallsStats implements BinderInternal.Observer { 


            final UidEntry uidEntry = getUidEntry(callingUid);

            uidEntry.callCount++;

            final CallStat callStat = uidEntry.getOrCreate(

                    s.binderClass, s.transactionCode, mScreenInteractive);

            callStat.callCount++;



            if (recordCall) {

                uidEntry.cpuTimeMicros += duration;

                uidEntry.recordedCallCount++;



                final CallStat callStat = uidEntry.getOrCreate(

                        s.binderClass, s.transactionCode, mScreenInteractive);

                callStat.callCount++;

                callStat.recordedCallCount++;

                callStat.cpuTimeMicros += duration;

                callStat.maxCpuTimeMicros = Math.max(callStat.maxCpuTimeMicros, duration);
@@ -245,6 +248,14 @@ public class BinderCallsStats implements BinderInternal.Observer { 
                    callStat.maxReplySizeBytes =

                            Math.max(callStat.maxReplySizeBytes, parcelReplySize);

                }

            } else {

                // Only record the total call count if we already track data for this key.

                // It helps to keep the memory usage down when sampling is enabled.

                final CallStat callStat = uidEntry.get(

                        s.binderClass, s.transactionCode, mScreenInteractive);

                if (callStat != null) {

                    callStat.callCount++;

                }

            }

        }

    }
@@ -459,7 +470,7 @@ public class BinderCallsStats implements BinderInternal.Observer { 
            pw.println(String.format("  %6d %s", entry.second, entry.first));

        }



        if (!mDetailedTracking && mPeriodicSamplingInterval != 1) {

        if (mPeriodicSamplingInterval != 1) {

            pw.println("");

            pw.println("/!\\ Displayed data is sampled. See sampling interval at the top.");

        }
@@ -488,6 +499,9 @@ public class BinderCallsStats implements BinderInternal.Observer { 
        return mRandom.nextInt() % mPeriodicSamplingInterval == 0;

    }



    /**

     * Sets to true to collect all the data.

     */

    public void setDetailedTracking(boolean enabled) {

        synchronized (mLock) {

            if (enabled != mDetailedTracking) {
@@ -546,7 +560,8 @@ public class BinderCallsStats implements BinderInternal.Observer { 
        // Number of calls for which we collected data for. We do not record data for all the calls

        // when sampling is on.

        public long recordedCallCount;

        // Real number of total calls.

        // Roughly the real number of total calls. We only track only track the API call count once

        // at least one non-sampled count happened.

        public long callCount;

        // Total CPU of all for all the recorded calls.

        // Approximate total CPU usage can be computed by
@@ -620,13 +635,19 @@ public class BinderCallsStats implements BinderInternal.Observer { 
        private Map<CallStatKey, CallStat> mCallStats = new ArrayMap<>();

        private CallStatKey mTempKey = new CallStatKey();



        CallStat getOrCreate(Class<? extends Binder> binderClass, int transactionCode,

        @Nullable

        CallStat get(Class<? extends Binder> binderClass, int transactionCode,

                boolean screenInteractive) {

            // Use a global temporary key to avoid creating new objects for every lookup.

            mTempKey.binderClass = binderClass;

            mTempKey.transactionCode = transactionCode;

            mTempKey.screenInteractive = screenInteractive;

            CallStat mapCallStat = mCallStats.get(mTempKey);

            return mCallStats.get(mTempKey);

        }



        CallStat getOrCreate(Class<? extends Binder> binderClass, int transactionCode,

                boolean screenInteractive) {

            CallStat mapCallStat = get(binderClass, transactionCode, screenInteractive);

            // Only create CallStat if it's a new entry, otherwise update existing instance

            if (mapCallStat == null) {

                mapCallStat = new CallStat(binderClass, transactionCode, screenInteractive);

core/tests/coretests/src/com/android/internal/os/BinderCallsStatsTest.java

+3 −9
Original line number Diff line number Diff line
@@ -90,7 +90,7 @@ public class BinderCallsStatsTest { 
        assertEquals(1, uidEntry.recordedCallCount);

        // Still sampled even for another API.

        callStatsList = new ArrayList(uidEntry.getCallStatsList());

        assertEquals(2, callStatsList.size());

        assertEquals(1, callStatsList.size());

    }



    @Test
@@ -221,20 +221,13 @@ public class BinderCallsStatsTest { 
        assertEquals(10, uidEntry.cpuTimeMicros);



        List<BinderCallsStats.CallStat> callStatsList = new ArrayList(uidEntry.getCallStatsList());

        assertEquals(2, callStatsList.size());

        assertEquals(1, callStatsList.size());



        BinderCallsStats.CallStat callStats = callStatsList.get(0);

        assertEquals(1, callStats.callCount);

        assertEquals(1, callStats.recordedCallCount);

        assertEquals(10, callStats.cpuTimeMicros);

        assertEquals(10, callStats.maxCpuTimeMicros);



        // Only call count should is tracked, rest is sampled.

        callStats = callStatsList.get(1);

        assertEquals(1, callStats.callCount);

        assertEquals(0, callStats.recordedCallCount);

        assertEquals(0, callStats.cpuTimeMicros);

        assertEquals(0, callStats.maxCpuTimeMicros);

    }



    private static class BinderWithGetTransactionName extends Binder {
@@ -586,6 +579,7 @@ public class BinderCallsStatsTest { 
                    };

                }

            });

            setSamplingInterval(1);

        }



        @Override