Automatically trace messages on shared loopers.
There are a handful of looper threads in the system_process that
are shared by dozens of different internal services. To help track
down what these operations are, tag the processing of each message
with a string that tries describing where it originated from: the
class name of the Handler, and the message number or class name of the
Runnable.
Bug: 28046299
Change-Id: I409ec43fea8daaae4fd70df05d4fed929a7249ae
diff --git a/core/java/android/os/Handler.java b/core/java/android/os/Handler.java
index 878b7a0..3c7c962 100644
--- a/core/java/android/os/Handler.java
+++ b/core/java/android/os/Handler.java
@@ -231,6 +231,18 @@
mAsynchronous = async;
}
+ /** {@hide} */
+ public String getTraceName(Message message) {
+ final StringBuilder sb = new StringBuilder();
+ sb.append(getClass().getName()).append(": ");
+ if (message.callback != null) {
+ sb.append(message.callback.getClass().getName());
+ } else {
+ sb.append("#").append(message.what);
+ }
+ return sb.toString();
+ }
+
/**
* Returns a string representing the name of the specified message.
* The default implementation will either return the class name of the
@@ -739,8 +751,8 @@
message.callback.run();
}
- final MessageQueue mQueue;
final Looper mLooper;
+ final MessageQueue mQueue;
final Callback mCallback;
final boolean mAsynchronous;
IMessenger mMessenger;
diff --git a/core/java/android/os/Looper.java b/core/java/android/os/Looper.java
index 34c880f..b58ff1f 100644
--- a/core/java/android/os/Looper.java
+++ b/core/java/android/os/Looper.java
@@ -72,6 +72,7 @@
final Thread mThread;
private Printer mLogging;
+ private long mTraceTag;
/** Initialize the current thread as a looper.
* This gives you a chance to create handlers that then reference
@@ -139,13 +140,23 @@
}
// This must be in a local variable, in case a UI event sets the logger
- Printer logging = me.mLogging;
+ final Printer logging = me.mLogging;
if (logging != null) {
logging.println(">>>>> Dispatching to " + msg.target + " " +
msg.callback + ": " + msg.what);
}
- msg.target.dispatchMessage(msg);
+ final long traceTag = me.mTraceTag;
+ if (traceTag != 0) {
+ Trace.traceBegin(traceTag, msg.target.getTraceName(msg));
+ }
+ try {
+ msg.target.dispatchMessage(msg);
+ } finally {
+ if (traceTag != 0) {
+ Trace.traceEnd(traceTag);
+ }
+ }
if (logging != null) {
logging.println("<<<<< Finished to " + msg.target + " " + msg.callback);
@@ -208,6 +219,11 @@
mLogging = printer;
}
+ /** {@hide} */
+ public void setTraceTag(long traceTag) {
+ mTraceTag = traceTag;
+ }
+
/**
* Quits the looper.
* <p>
diff --git a/core/java/com/android/internal/os/BackgroundThread.java b/core/java/com/android/internal/os/BackgroundThread.java
index d6f7b20..cffba01 100644
--- a/core/java/com/android/internal/os/BackgroundThread.java
+++ b/core/java/com/android/internal/os/BackgroundThread.java
@@ -18,6 +18,7 @@
import android.os.Handler;
import android.os.HandlerThread;
+import android.os.Trace;
/**
* Shared singleton background thread for each process.
@@ -34,6 +35,7 @@
if (sInstance == null) {
sInstance = new BackgroundThread();
sInstance.start();
+ sInstance.getLooper().setTraceTag(Trace.TRACE_TAG_ACTIVITY_MANAGER);
sHandler = new Handler(sInstance.getLooper());
}
}
diff --git a/services/core/java/com/android/server/DisplayThread.java b/services/core/java/com/android/server/DisplayThread.java
index aa0a805..9ef0259 100644
--- a/services/core/java/com/android/server/DisplayThread.java
+++ b/services/core/java/com/android/server/DisplayThread.java
@@ -17,6 +17,7 @@
package com.android.server;
import android.os.Handler;
+import android.os.Trace;
/**
* Shared singleton foreground thread for the system. This is a thread for
@@ -36,6 +37,7 @@
if (sInstance == null) {
sInstance = new DisplayThread();
sInstance.start();
+ sInstance.getLooper().setTraceTag(Trace.TRACE_TAG_ACTIVITY_MANAGER);
sHandler = new Handler(sInstance.getLooper());
}
}
diff --git a/services/core/java/com/android/server/FgThread.java b/services/core/java/com/android/server/FgThread.java
index 03765db..5f85cba 100644
--- a/services/core/java/com/android/server/FgThread.java
+++ b/services/core/java/com/android/server/FgThread.java
@@ -17,6 +17,7 @@
package com.android.server;
import android.os.Handler;
+import android.os.Trace;
/**
* Shared singleton foreground thread for the system. This is a thread for regular
@@ -38,6 +39,7 @@
if (sInstance == null) {
sInstance = new FgThread();
sInstance.start();
+ sInstance.getLooper().setTraceTag(Trace.TRACE_TAG_ACTIVITY_MANAGER);
sHandler = new Handler(sInstance.getLooper());
}
}
diff --git a/services/core/java/com/android/server/IoThread.java b/services/core/java/com/android/server/IoThread.java
index 0f29857..ad4c194 100644
--- a/services/core/java/com/android/server/IoThread.java
+++ b/services/core/java/com/android/server/IoThread.java
@@ -17,6 +17,7 @@
package com.android.server;
import android.os.Handler;
+import android.os.Trace;
/**
* Shared singleton I/O thread for the system. This is a thread for non-background
@@ -35,6 +36,7 @@
if (sInstance == null) {
sInstance = new IoThread();
sInstance.start();
+ sInstance.getLooper().setTraceTag(Trace.TRACE_TAG_ACTIVITY_MANAGER);
sHandler = new Handler(sInstance.getLooper());
}
}
diff --git a/services/core/java/com/android/server/UiThread.java b/services/core/java/com/android/server/UiThread.java
index 0beb77f..c06afc2 100644
--- a/services/core/java/com/android/server/UiThread.java
+++ b/services/core/java/com/android/server/UiThread.java
@@ -17,6 +17,7 @@
package com.android.server;
import android.os.Handler;
+import android.os.Trace;
/**
* Shared singleton thread for showing UI. This is a foreground thread, and in
@@ -35,6 +36,7 @@
if (sInstance == null) {
sInstance = new UiThread();
sInstance.start();
+ sInstance.getLooper().setTraceTag(Trace.TRACE_TAG_ACTIVITY_MANAGER);
sHandler = new Handler(sInstance.getLooper());
}
}