From 604224563692e7bd10fcdc1373ecdbd68b48b830 Mon Sep 17 00:00:00 2001
From: Fyodor Kupolov <fkupolov@google.com>
Date: Mon, 28 Aug 2017 17:15:44 -0700
Subject: Do not allow multi-threaded usage of TimingsTraceLog

Test: bit FrameworksCoreTests:android.util.TimingsTraceLogTest
Bug: 65058451
Change-Id: I3e594b67fa3e46a77fc3c509c4ca44457da2f57c
---
 core/java/android/util/TimingsTraceLog.java        | 14 +++++
 .../src/android/util/TimingsTraceLogTest.java      | 70 ++++++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 core/tests/coretests/src/android/util/TimingsTraceLogTest.java

diff --git a/core/java/android/util/TimingsTraceLog.java b/core/java/android/util/TimingsTraceLog.java
index 36e9f77bb831..3e6f09bfa799 100644
--- a/core/java/android/util/TimingsTraceLog.java
+++ b/core/java/android/util/TimingsTraceLog.java
@@ -25,6 +25,7 @@ import java.util.Deque;
 
 /**
  * Helper class for reporting boot and shutdown timing metrics.
+ * <p>Note: This class is not thread-safe. Use a separate copy for other threads</p>
  * @hide
  */
 public class TimingsTraceLog {
@@ -34,10 +35,12 @@ public class TimingsTraceLog {
             DEBUG_BOOT_TIME ? new ArrayDeque<>() : null;
     private final String mTag;
     private long mTraceTag;
+    private long mThreadId;
 
     public TimingsTraceLog(String tag, long traceTag) {
         mTag = tag;
         mTraceTag = traceTag;
+        mThreadId = Thread.currentThread().getId();
     }
 
     /**
@@ -45,6 +48,7 @@ public class TimingsTraceLog {
      * @param name name to appear in trace
      */
     public void traceBegin(String name) {
+        assertSameThread();
         Trace.traceBegin(mTraceTag, name);
         if (DEBUG_BOOT_TIME) {
             mStartTimes.push(Pair.create(name, SystemClock.elapsedRealtime()));
@@ -56,6 +60,7 @@ public class TimingsTraceLog {
      * Also {@link #logDuration logs} the duration.
      */
     public void traceEnd() {
+        assertSameThread();
         Trace.traceEnd(mTraceTag);
         if (!DEBUG_BOOT_TIME) {
             return;
@@ -68,6 +73,15 @@ public class TimingsTraceLog {
         logDuration(event.first, (SystemClock.elapsedRealtime() - event.second));
     }
 
+    private void assertSameThread() {
+        final Thread currentThread = Thread.currentThread();
+        if (currentThread.getId() != mThreadId) {
+            throw new IllegalStateException("Instance of TimingsTraceLog can only be called from "
+                    + "the thread it was created on (tid: " + mThreadId + "), but was from "
+                    + currentThread.getName() + " (tid: " + currentThread.getId() + ")");
+        }
+    }
+
     /**
      * Log the duration so it can be parsed by external tools for performance reporting
      */
diff --git a/core/tests/coretests/src/android/util/TimingsTraceLogTest.java b/core/tests/coretests/src/android/util/TimingsTraceLogTest.java
new file mode 100644
index 000000000000..7bb4ab835e4f
--- /dev/null
+++ b/core/tests/coretests/src/android/util/TimingsTraceLogTest.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+package android.util;
+
+import static org.junit.Assert.assertTrue;
+
+import android.os.Trace;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.util.ArrayList;
+import java.util.List;
+
+
+/**
+ * Tests for {@link TimingsTraceLog}.
+ * <p>Usage: bit FrameworksCoreTests:android.util.TimingsTraceLogTest
+ */
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class TimingsTraceLogTest {
+
+    @Test
+    public void testDifferentThreads() throws Exception {
+        TimingsTraceLog log = new TimingsTraceLog("TEST", Trace.TRACE_TAG_APP);
+        // Should be able to log on the same thread
+        log.traceBegin("test");
+        log.traceEnd();
+        final List<String> errors = new ArrayList<>();
+        // Calling from a different thread should fail
+        Thread t = new Thread(() -> {
+            try {
+                log.traceBegin("test");
+                errors.add("traceBegin should fail on a different thread");
+            } catch (IllegalStateException expected) {
+            }
+            try {
+                log.traceEnd();
+                errors.add("traceEnd should fail on a different thread");
+            } catch (IllegalStateException expected) {
+            }
+            // Verify that creating a new log will work
+            TimingsTraceLog log2 = new TimingsTraceLog("TEST", Trace.TRACE_TAG_APP);
+            log2.traceBegin("test");
+            log2.traceEnd();
+
+        });
+        t.start();
+        t.join();
+        assertTrue(errors.toString(), errors.isEmpty());
+    }
+
+}
-- 
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