From 2f72aa0bd1b59b6503edc9a8330bc004394d7fee Mon Sep 17 00:00:00 2001
From: Lucas Dupin <dupin@google.com>
Date: Wed, 8 Dec 2021 19:50:27 -0800
Subject: [PATCH] Log UI events to traces

Add LogBuffer tags to perfetto traces in order to simplify the process
of reading them.

A new track will indicate the state of notification, lock screen, AOD,
etc.

Bug: 207049735
Test: atest TraceDevTest
Change-Id: I3253c0f5a369ad4a25d6646daa62810644553a36
---
 core/java/android/os/Trace.java               | 40 +++++++++++++++++++
 core/jni/android_os_Trace.cpp                 | 22 ++++++++++
 .../src/com/android/systemui/log/LogBuffer.kt |  6 ++-
 3 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/core/java/android/os/Trace.java b/core/java/android/os/Trace.java
index ddb6533547bb..d974e0c0713a 100644
--- a/core/java/android/os/Trace.java
+++ b/core/java/android/os/Trace.java
@@ -131,6 +131,10 @@ public final class Trace {
     private static native void nativeAsyncTraceBegin(long tag, String name, int cookie);
     @FastNative
     private static native void nativeAsyncTraceEnd(long tag, String name, int cookie);
+    @FastNative
+    private static native void nativeInstant(long tag, String name);
+    @FastNative
+    private static native void nativeInstantForTrack(long tag, String trackName, String name);
 
     private Trace() {
     }
@@ -257,6 +261,42 @@ public final class Trace {
         }
     }
 
+    /**
+     * Writes a trace message to indicate that a given section of code was invoked.
+     *
+     * @param traceTag The trace tag.
+     * @param methodName The method name to appear in the trace.
+     * @hide
+     */
+    public static void instant(long traceTag, String methodName) {
+        if (methodName == null) {
+            throw new IllegalArgumentException("methodName cannot be null");
+        }
+        if (isTagEnabled(traceTag)) {
+            nativeInstant(traceTag, methodName);
+        }
+    }
+
+    /**
+     * Writes a trace message to indicate that a given section of code was invoked.
+     *
+     * @param traceTag The trace tag.
+     * @param trackName The track where the event should appear in the trace.
+     * @param methodName The method name to appear in the trace.
+     * @hide
+     */
+    public static void instantForTrack(long traceTag, String trackName, String methodName) {
+        if (trackName == null) {
+            throw new IllegalArgumentException("trackName cannot be null");
+        }
+        if (methodName == null) {
+            throw new IllegalArgumentException("methodName cannot be null");
+        }
+        if (isTagEnabled(traceTag)) {
+            nativeInstantForTrack(traceTag, trackName, methodName);
+        }
+    }
+
     /**
      * Checks whether or not tracing is currently enabled. This is useful to avoid intermediate
      * string creation for trace sections that require formatting. It is not necessary
diff --git a/core/jni/android_os_Trace.cpp b/core/jni/android_os_Trace.cpp
index f67007cda209..85fd5d99e473 100644
--- a/core/jni/android_os_Trace.cpp
+++ b/core/jni/android_os_Trace.cpp
@@ -90,6 +90,22 @@ static void android_os_Trace_nativeSetTracingEnabled(JNIEnv*, jclass, jboolean e
     atrace_set_tracing_enabled(enabled);
 }
 
+static void android_os_Trace_nativeInstant(JNIEnv* env, jclass,
+        jlong tag, jstring nameStr) {
+    withString(env, nameStr, [tag](char* str) {
+        atrace_instant(tag, str);
+    });
+}
+
+static void android_os_Trace_nativeInstantForTrack(JNIEnv* env, jclass,
+        jlong tag, jstring trackStr, jstring nameStr) {
+    withString(env, trackStr, [env, tag, nameStr](char* track) {
+        withString(env, nameStr, [tag, track](char* name) {
+            atrace_instant_for_track(tag, track, name);
+        });
+    });
+}
+
 static const JNINativeMethod gTraceMethods[] = {
     /* name, signature, funcPtr */
     { "nativeSetAppTracingAllowed",
@@ -116,6 +132,12 @@ static const JNINativeMethod gTraceMethods[] = {
     { "nativeAsyncTraceEnd",
             "(JLjava/lang/String;I)V",
             (void*)android_os_Trace_nativeAsyncTraceEnd },
+    { "nativeInstant",
+            "(JLjava/lang/String;)V",
+            (void*)android_os_Trace_nativeInstant },
+    { "nativeInstantForTrack",
+            "(JLjava/lang/String;Ljava/lang/String;)V",
+            (void*)android_os_Trace_nativeInstantForTrack },
 
     // ----------- @CriticalNative  ----------------
     { "nativeGetEnabledTags",
diff --git a/packages/SystemUI/src/com/android/systemui/log/LogBuffer.kt b/packages/SystemUI/src/com/android/systemui/log/LogBuffer.kt
index c1db8edf4119..90064172dd36 100644
--- a/packages/SystemUI/src/com/android/systemui/log/LogBuffer.kt
+++ b/packages/SystemUI/src/com/android/systemui/log/LogBuffer.kt
@@ -16,6 +16,7 @@
 
 package com.android.systemui.log
 
+import android.os.Trace
 import android.util.Log
 import com.android.systemui.log.dagger.LogModule
 import java.io.PrintWriter
@@ -169,7 +170,7 @@ class LogBuffer(
         buffer.add(message as LogMessageImpl)
         if (logcatEchoTracker.isBufferLoggable(name, message.level) ||
                 logcatEchoTracker.isTagLoggable(message.tag, message.level)) {
-            echoToLogcat(message)
+            echo(message)
         }
     }
 
@@ -219,7 +220,7 @@ class LogBuffer(
         pw.println(message.printer(message))
     }
 
-    private fun echoToLogcat(message: LogMessage) {
+    private fun echo(message: LogMessage) {
         val strMessage = message.printer(message)
         when (message.level) {
             LogLevel.VERBOSE -> Log.v(message.tag, strMessage)
@@ -229,6 +230,7 @@ class LogBuffer(
             LogLevel.ERROR -> Log.e(message.tag, strMessage)
             LogLevel.WTF -> Log.wtf(message.tag, strMessage)
         }
+        Trace.instantForTrack(Trace.TRACE_TAG_APP, "UI Events", strMessage)
     }
 }