Baseline `Trace` support for SysUI.

SysUI code relies on the tracing APIs, which are often used for
investigating performance-sensitive operations on physical devices.

As this tracing information is less useful under the Ravenwood
environment, we offer a baseline no-op implementation to support
existing code.  (There are no APIs to "read back" tracing
information for a test to inspect, which is another reason it's
okay to no-op for now.)

Bug: 319647875
Test: atest FrameworksCoreTestsRavenwood
Change-Id: I52865d7da4c38d350edc7e9dc0239fc1b130048d

core/java/android/os/Trace.java

@@ -36,6 +36,7 @@ import dalvik.annotation.optimization.FastNative;
  * href="{@docRoot}tools/debugging/systrace.html">Analyzing Display and Performance
  * with Systrace</a>.
  */
+@android.ravenwood.annotation.RavenwoodKeepWholeClass
 public final class Trace {
     /*
      * Writes trace events to the kernel trace buffer.  These trace events can be
@@ -123,10 +124,26 @@ public final class Trace {
 
     @UnsupportedAppUsage
     @CriticalNative
+    @android.ravenwood.annotation.RavenwoodReplace
     private static native long nativeGetEnabledTags();
+    @android.ravenwood.annotation.RavenwoodReplace
     private static native void nativeSetAppTracingAllowed(boolean allowed);
+    @android.ravenwood.annotation.RavenwoodReplace
     private static native void nativeSetTracingEnabled(boolean allowed);
 
+    private static long nativeGetEnabledTags$ravenwood() {
+        // Tracing currently completely disabled under Ravenwood
+        return 0;
+    }
+
+    private static void nativeSetAppTracingAllowed$ravenwood(boolean allowed) {
+        // Tracing currently completely disabled under Ravenwood
+    }
+
+    private static void nativeSetTracingEnabled$ravenwood(boolean allowed) {
+        // Tracing currently completely disabled under Ravenwood
+    }
+
     @FastNative
     private static native void nativeTraceCounter(long tag, String name, long value);
     @FastNative

core/tests/coretests/src/android/os/TraceTest.java

@@ -34,7 +34,6 @@ import org.junit.runner.RunWith;
  * while tracing on the emulator and then run traceview to view the trace.
  */
 @RunWith(AndroidJUnit4.class)
-@IgnoreUnderRavenwood(blockedBy = Trace.class)
 public class TraceTest {
     private static final String TAG = "TraceTest";
 
@@ -45,8 +44,52 @@ public class TraceTest {
     private int fMethodCalls = 0;
     private int gMethodCalls = 0;
 
+    @Test
+    public void testEnableDisable() {
+        // Currently only verifying that we can invoke without crashing
+        Trace.setTracingEnabled(true, 0);
+        Trace.setTracingEnabled(false, 0);
+
+        Trace.setAppTracingAllowed(true);
+        Trace.setAppTracingAllowed(false);
+    }
+
+    @Test
+    public void testBeginEnd() {
+        // Currently only verifying that we can invoke without crashing
+        Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, TAG);
+        Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
+
+        Trace.asyncTraceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, TAG, 42);
+        Trace.asyncTraceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER, TAG, 42);
+
+        Trace.asyncTraceForTrackBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, TAG, TAG, 42);
+        Trace.asyncTraceForTrackEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER, TAG, 42);
+
+        Trace.beginSection(TAG);
+        Trace.endSection();
+
+        Trace.beginAsyncSection(TAG, 42);
+        Trace.endAsyncSection(TAG, 42);
+    }
+
+    @Test
+    public void testCounter() {
+        // Currently only verifying that we can invoke without crashing
+        Trace.traceCounter(Trace.TRACE_TAG_ACTIVITY_MANAGER, TAG, 42);
+        Trace.setCounter(TAG, 42);
+    }
+
+    @Test
+    public void testInstant() {
+        // Currently only verifying that we can invoke without crashing
+        Trace.instant(Trace.TRACE_TAG_ACTIVITY_MANAGER, TAG);
+        Trace.instantForTrack(Trace.TRACE_TAG_ACTIVITY_MANAGER, TAG, TAG);
+    }
+
     @Test
     public void testNullStrings() {
+        // Currently only verifying that we can invoke without crashing
         Trace.traceCounter(Trace.TRACE_TAG_ACTIVITY_MANAGER, null, 42);
         Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, null);
 
@@ -62,6 +105,7 @@ public class TraceTest {
 
     @Test
     @SmallTest
+    @IgnoreUnderRavenwood(blockedBy = Debug.class)
     public void testNativeTracingFromJava()
     {
         long start = System.currentTimeMillis();
@@ -82,6 +126,7 @@ public class TraceTest {
     
     // This should not run in the automated suite.
     @Suppress
+    @IgnoreUnderRavenwood(blockedBy = Debug.class)
     public void disableTestNativeTracingFromC()
     {
         long start = System.currentTimeMillis();
@@ -97,6 +142,7 @@ public class TraceTest {
     @Test
     @LargeTest
     @Suppress  // Failing.
+    @IgnoreUnderRavenwood(blockedBy = Debug.class)
     public void testMethodTracing()
     {
         long start = System.currentTimeMillis();

ravenwood/ravenwood-annotation-allowed-classes.txt

@@ -67,6 +67,7 @@ android.os.ServiceSpecificException
 android.os.SystemClock
 android.os.ThreadLocalWorkSource
 android.os.TimestampedValue
+android.os.Trace
 android.os.UidBatteryConsumer
 android.os.UidBatteryConsumer$Builder
 android.os.UserHandle