Spatializer: Add rate based stats
A new class ThreadSnapshot encapsulates
current (and future) thread based statistics.
Test: adb shell dumpsys media.audio_flinger --all
Test: atest media_threadsnapshot_tests
Bug: 228648325
Change-Id: Idbfdee08032c56f2c47e2e48d2ceb0656168c125
diff --git a/media/utils/ThreadSnapshot.cpp b/media/utils/ThreadSnapshot.cpp
new file mode 100644
index 0000000..382738e
--- /dev/null
+++ b/media/utils/ThreadSnapshot.cpp
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "ThreadSnapshot"
+#include <utils/Log.h>
+#include <utils/Timers.h>
+#include <mediautils/ThreadSnapshot.h>
+
+#include <mediautils/Process.h>
+
+namespace android::mediautils {
+
+pid_t ThreadSnapshot::getTid() const {
+ std::lock_guard lg(mLock);
+ return mState.mTid;
+}
+
+void ThreadSnapshot::setTid(pid_t tid) {
+ std::lock_guard lg(mLock);
+ if (mState.mTid == tid) return;
+ mState.reset(tid);
+}
+
+void ThreadSnapshot::reset() {
+ std::lock_guard lg(mLock);
+ mState.reset(mState.mTid);
+}
+
+void ThreadSnapshot::onBegin() {
+ std::string sched = getThreadSchedAsString(getTid()); // tid could race here,
+ // accept as benign.
+ std::lock_guard lg(mLock);
+ mState.onBegin(std::move(sched));
+}
+
+void ThreadSnapshot::onEnd() {
+ std::lock_guard lg(mLock);
+ mState.onEnd();
+}
+
+std::string ThreadSnapshot::toString() const {
+ // Make a local copy of the stats data under lock.
+ State state;
+ {
+ std::lock_guard lg(mLock);
+ state = mState;
+ }
+ return state.toString();
+}
+
+void ThreadSnapshot::State::reset(pid_t tid) {
+ mTid = tid;
+ mBeginTimeNs = -2;
+ mEndTimeNs = -1;
+ mCumulativeTimeNs = 0;
+ mBeginSched.clear();
+}
+
+void ThreadSnapshot::State::onBegin(std::string sched) {
+ if (mBeginTimeNs < mEndTimeNs) {
+ mBeginTimeNs = systemTime();
+ mBeginSched = std::move(sched);
+ }
+}
+
+void ThreadSnapshot::State::onEnd() {
+ if (mEndTimeNs < mBeginTimeNs) {
+ mEndTimeNs = systemTime();
+ mCumulativeTimeNs += mEndTimeNs - mBeginTimeNs;
+ }
+}
+
+std::string ThreadSnapshot::State::toString() const {
+ if (mBeginTimeNs < 0) return {}; // never begun.
+
+ // compute time intervals.
+ const int64_t nowNs = systemTime();
+ int64_t cumulativeTimeNs = mCumulativeTimeNs;
+ int64_t diffNs = mEndTimeNs - mBeginTimeNs; // if onEnd() isn't matched, diffNs < 0.
+ if (diffNs < 0) {
+ diffNs = nowNs - mBeginTimeNs;
+ cumulativeTimeNs += diffNs;
+ }
+ // normalization for rate variables
+ const double lastRunPerSec = 1e9 / diffNs;
+ const double totalPerSec = 1e9 / cumulativeTimeNs;
+
+ // HANDLE THE SCHEDULER STATISTICS HERE
+ // current and differential statistics for the scheduler.
+ std::string schedNow = getThreadSchedAsString(mTid);
+ const auto schedMapThen = parseThreadSchedString(mBeginSched);
+ const auto schedMapNow = parseThreadSchedString(schedNow);
+ static const char * schedDiffKeyList[] = {
+ "se.sum_exec_runtime",
+ "se.nr_migrations",
+ "se.statistics.wait_sum",
+ "se.statistics.wait_count",
+ "se.statistics.iowait_sum",
+ "se.statistics.iowait_count",
+ "se.statistics.nr_forced_migrations",
+ "nr_involuntary_switches",
+ };
+
+ // compute differential rate statistics.
+ std::string diffString;
+ for (const auto diffKey : schedDiffKeyList) {
+ if (auto itThen = schedMapThen.find(diffKey);
+ itThen != schedMapThen.end()) {
+
+ if (auto itNow = schedMapNow.find(diffKey);
+ itNow != schedMapNow.end()) {
+ auto diff = itNow->second - itThen->second;
+ diff *= lastRunPerSec;
+ auto total = itNow->second * totalPerSec;
+ diffString.append(diffKey).append(" last-run:")
+ .append(std::to_string(diff))
+ .append(" cumulative:")
+ .append(std::to_string(total))
+ .append("\n");
+ }
+ }
+ }
+
+ if (!diffString.empty()) {
+ schedNow.append("*** per second stats ***\n").append(diffString);
+ }
+
+ // Return snapshot string.
+ return schedNow;
+}
+
+} // android::mediautils