Merge "Cleanup and consistency around system server profiling."

core/java/com/android/internal/os/SystemServerClassLoaderFactory.java

@@ -87,6 +87,10 @@ public final class SystemServerClassLoaderFactory {
         if (isTestOnly) {
             return true;
         }
+        // If system server is being profiled, it's OK to create class loaders anytime.
+        if (ZygoteInit.shouldProfileSystemServer()) {
+            return true;
+        }
         return false;
     }
 

core/java/com/android/internal/os/ZygoteInit.java

@@ -238,6 +238,21 @@ public class ZygoteInit {
         Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
     }
 
+    private static boolean isExperimentEnabled(String experiment) {
+        boolean defaultValue = SystemProperties.getBoolean(
+                "dalvik.vm." + experiment,
+                /*def=*/false);
+        // Can't use device_config since we are the zygote, and it's not initialized at this point.
+        return SystemProperties.getBoolean(
+                "persist.device_config." + DeviceConfig.NAMESPACE_RUNTIME_NATIVE_BOOT
+                        + "." + experiment,
+                defaultValue);
+    }
+
+    /* package-private */ static boolean shouldProfileSystemServer() {
+        return isExperimentEnabled("profilesystemserver");
+    }
+
     /**
      * Performs Zygote process initialization. Loads and initializes commonly used classes.
      *
@@ -341,14 +356,7 @@ public class ZygoteInit {
             // If we are profiling the boot image, reset the Jit counters after preloading the
             // classes. We want to preload for performance, and we can use method counters to
             // infer what clases are used after calling resetJitCounters, for profile purposes.
-            // Can't use device_config since we are the zygote.
-            String prop = SystemProperties.get(
-                    "persist.device_config.runtime_native_boot.profilebootclasspath", "");
-            // Might be empty if the property is unset since the default is "".
-            if (prop.length() == 0) {
-                prop = SystemProperties.get("dalvik.vm.profilebootclasspath", "");
-            }
-            if ("true".equals(prop)) {
+            if (isExperimentEnabled("profilebootclasspath")) {
                 Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "ResetJitCounters");
                 VMRuntime.resetJitCounters();
                 Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
@@ -489,16 +497,6 @@ public class ZygoteInit {
         ZygoteHooks.gcAndFinalize();
     }
 
-    private static boolean shouldProfileSystemServer() {
-        boolean defaultValue = SystemProperties.getBoolean("dalvik.vm.profilesystemserver",
-                /*default=*/ false);
-        // Can't use DeviceConfig since it's not initialized at this point.
-        return SystemProperties.getBoolean(
-                "persist.device_config." + DeviceConfig.NAMESPACE_RUNTIME_NATIVE_BOOT
-                        + ".profilesystemserver",
-                defaultValue);
-    }
-
     /**
      * Finish remaining work for the newly forked system server process.
      */
@@ -585,6 +583,13 @@ public class ZygoteInit {
      * in the forked system server process in the zygote SELinux domain.
      */
     private static void prefetchStandaloneSystemServerJars() {
+        if (shouldProfileSystemServer()) {
+            // We don't prefetch AOT artifacts if we are profiling system server, as we are going to
+            // JIT it.
+            // This method only gets called from native and should already be skipped if we profile
+            // system server. Still, be robust and check it again.
+            return;
+        }
         String envStr = Os.getenv("STANDALONE_SYSTEMSERVER_JARS");
         if (TextUtils.isEmpty(envStr)) {
             return;

core/jni/com_android_internal_os_Zygote.cpp

@@ -343,6 +343,7 @@ enum MountExternalKind {
 // Must match values in com.android.internal.os.Zygote.
 enum RuntimeFlags : uint32_t {
     DEBUG_ENABLE_JDWP = 1,
+    PROFILE_SYSTEM_SERVER = 1 << 14,
     PROFILE_FROM_SHELL = 1 << 15,
     MEMORY_TAG_LEVEL_MASK = (1 << 19) | (1 << 20),
     MEMORY_TAG_LEVEL_TBI = 1 << 19,
@@ -1634,9 +1635,11 @@ static void SpecializeCommon(JNIEnv* env, uid_t uid, gid_t gid, jintArray gids,
                                            instruction_set.value().c_str());
     }
 
-    if (is_system_server) {
+    if (is_system_server && !(runtime_flags & RuntimeFlags::PROFILE_SYSTEM_SERVER)) {
         // Prefetch the classloader for the system server. This is done early to
         // allow a tie-down of the proper system server selinux domain.
+        // We don't prefetch when the system server is being profiled to avoid
+        // loading AOT code.
         env->CallStaticObjectMethod(gZygoteInitClass, gGetOrCreateSystemServerClassLoader);
         if (env->ExceptionCheck()) {
             // Be robust here. The Java code will attempt to create the classloader