ART: Add ThreadGroup API support

Add support for GetThreadGroupInfo, GetThreadGroupChildren and
GetTopThreadGroups. Add tests.

Bug: 31455788
Test: m test-art-host-run-test-925-threadgroups
Change-Id: I56809c95dfd2666c2e18769a8960d6b1604274b4
diff --git a/test/925-threadgroups/build b/test/925-threadgroups/build
new file mode 100755
index 0000000..898e2e5
--- /dev/null
+++ b/test/925-threadgroups/build
@@ -0,0 +1,17 @@
+#!/bin/bash
+#
+# Copyright 2016 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.
+
+./default-build "$@" --experimental agents
diff --git a/test/925-threadgroups/expected.txt b/test/925-threadgroups/expected.txt
new file mode 100644
index 0000000..7d1a259
--- /dev/null
+++ b/test/925-threadgroups/expected.txt
@@ -0,0 +1,16 @@
+java.lang.ThreadGroup[name=main,maxpri=10]
+  java.lang.ThreadGroup[name=system,maxpri=10]
+  main
+  10
+  false
+java.lang.ThreadGroup[name=system,maxpri=10]
+  null
+  system
+  10
+  false
+main:
+  [Thread[main,5,main]]
+  []
+system:
+  [Thread[FinalizerDaemon,5,system], Thread[FinalizerWatchdogDaemon,5,system], Thread[HeapTaskDaemon,5,system], Thread[ReferenceQueueDaemon,5,system], Thread[Signal Catcher,5,system]]
+  [java.lang.ThreadGroup[name=main,maxpri=10]]
diff --git a/test/925-threadgroups/info.txt b/test/925-threadgroups/info.txt
new file mode 100644
index 0000000..875a5f6
--- /dev/null
+++ b/test/925-threadgroups/info.txt
@@ -0,0 +1 @@
+Tests basic functions in the jvmti plugin.
diff --git a/test/925-threadgroups/run b/test/925-threadgroups/run
new file mode 100755
index 0000000..4379349
--- /dev/null
+++ b/test/925-threadgroups/run
@@ -0,0 +1,19 @@
+#!/bin/bash
+#
+# Copyright 2016 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+./default-run "$@" --experimental agents \
+                   --experimental runtime-plugins \
+                   --jvmti
diff --git a/test/925-threadgroups/src/Main.java b/test/925-threadgroups/src/Main.java
new file mode 100644
index 0000000..f16c0d6
--- /dev/null
+++ b/test/925-threadgroups/src/Main.java
@@ -0,0 +1,94 @@
+/*
+ * 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.
+ */
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+public class Main {
+  public static void main(String[] args) throws Exception {
+    System.loadLibrary(args[1]);
+
+    doTest();
+  }
+
+  private static void doTest() throws Exception {
+    Thread t1 = Thread.currentThread();
+    ThreadGroup curGroup = t1.getThreadGroup();
+
+    ThreadGroup rootGroup = curGroup;
+    while (rootGroup.getParent() != null) {
+      rootGroup = rootGroup.getParent();
+    }
+
+    ThreadGroup topGroups[] = getTopThreadGroups();
+    if (topGroups == null || topGroups.length != 1 || topGroups[0] != rootGroup) {
+      System.out.println(Arrays.toString(topGroups));
+      throw new RuntimeException("Unexpected topGroups");
+    }
+
+    printThreadGroupInfo(curGroup);
+    printThreadGroupInfo(rootGroup);
+
+    checkChildren(curGroup);
+  }
+
+  private static void printThreadGroupInfo(ThreadGroup tg) {
+    Object[] threadGroupInfo = getThreadGroupInfo(tg);
+    if (threadGroupInfo == null || threadGroupInfo.length != 4) {
+      System.out.println(Arrays.toString(threadGroupInfo));
+      throw new RuntimeException("threadGroupInfo length wrong");
+    }
+
+    System.out.println(tg);
+    System.out.println("  " + threadGroupInfo[0]);  // Parent
+    System.out.println("  " + threadGroupInfo[1]);  // Name
+    System.out.println("  " + threadGroupInfo[2]);  // Priority
+    System.out.println("  " + threadGroupInfo[3]);  // Daemon
+  }
+
+  private static void checkChildren(ThreadGroup tg) {
+    Object[] data = getThreadGroupChildren(tg);
+    Thread[] threads = (Thread[])data[0];
+    ThreadGroup[] groups = (ThreadGroup[])data[1];
+
+    Arrays.sort(threads, THREAD_COMP);
+    Arrays.sort(groups, THREADGROUP_COMP);
+    System.out.println(tg.getName() + ":");
+    System.out.println("  " + Arrays.toString(threads));
+    System.out.println("  " + Arrays.toString(groups));
+
+    if (tg.getParent() != null) {
+      checkChildren(tg.getParent());
+    }
+  }
+
+  private final static Comparator<Thread> THREAD_COMP = new Comparator<Thread>() {
+    public int compare(Thread o1, Thread o2) {
+      return o1.getName().compareTo(o2.getName());
+    }
+  };
+
+  private final static Comparator<ThreadGroup> THREADGROUP_COMP = new Comparator<ThreadGroup>() {
+    public int compare(ThreadGroup o1, ThreadGroup o2) {
+      return o1.getName().compareTo(o2.getName());
+    }
+  };
+
+  private static native ThreadGroup[] getTopThreadGroups();
+  private static native Object[] getThreadGroupInfo(ThreadGroup tg);
+  // Returns an array where element 0 is an array of threads and element 1 is an array of groups.
+  private static native Object[] getThreadGroupChildren(ThreadGroup tg);
+}
diff --git a/test/925-threadgroups/threadgroups.cc b/test/925-threadgroups/threadgroups.cc
new file mode 100644
index 0000000..6c6e835
--- /dev/null
+++ b/test/925-threadgroups/threadgroups.cc
@@ -0,0 +1,127 @@
+/*
+ * 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.
+ */
+
+#include <stdio.h>
+
+#include "android-base/stringprintf.h"
+#include "base/macros.h"
+#include "base/logging.h"
+#include "jni.h"
+#include "openjdkjvmti/jvmti.h"
+#include "ScopedLocalRef.h"
+
+#include "ti-agent/common_helper.h"
+#include "ti-agent/common_load.h"
+
+namespace art {
+namespace Test925ThreadGroups {
+
+//   private static native Object[] getThreadGroupInfo();
+//   // Returns an array where element 0 is an array of threads and element 1 is an array of groups.
+//   private static native Object[] getThreadGroupChildren();
+
+extern "C" JNIEXPORT jobjectArray JNICALL Java_Main_getTopThreadGroups(
+    JNIEnv* env, jclass Main_klass ATTRIBUTE_UNUSED) {
+  jthreadGroup* groups;
+  jint group_count;
+  jvmtiError result = jvmti_env->GetTopThreadGroups(&group_count, &groups);
+  if (JvmtiErrorToException(env, result)) {
+    return nullptr;
+  }
+
+  auto callback = [&](jint index) -> jobject {
+    return groups[index];
+  };
+  jobjectArray ret = CreateObjectArray(env, group_count, "java/lang/ThreadGroup", callback);
+
+  jvmti_env->Deallocate(reinterpret_cast<unsigned char*>(groups));
+
+  return ret;
+}
+
+extern "C" JNIEXPORT jobjectArray JNICALL Java_Main_getThreadGroupInfo(
+    JNIEnv* env, jclass Main_klass ATTRIBUTE_UNUSED, jthreadGroup group) {
+  jvmtiThreadGroupInfo info;
+  jvmtiError result = jvmti_env->GetThreadGroupInfo(group, &info);
+  if (JvmtiErrorToException(env, result)) {
+    return nullptr;
+  }
+
+  auto callback = [&](jint index) -> jobject {
+    switch (index) {
+      // The parent.
+      case 0:
+        return info.parent;
+
+      // The name.
+      case 1:
+        return (info.name == nullptr) ? nullptr : env->NewStringUTF(info.name);
+
+      // The priority. Use a string for simplicity of construction.
+      case 2:
+        return env->NewStringUTF(android::base::StringPrintf("%d", info.max_priority).c_str());
+
+      // Whether it's a daemon. Use a string for simplicity of construction.
+      case 3:
+        return env->NewStringUTF(info.is_daemon == JNI_TRUE ? "true" : "false");
+    }
+    LOG(FATAL) << "Should not reach here";
+    UNREACHABLE();
+  };
+  return CreateObjectArray(env, 4, "java/lang/Object", callback);
+}
+
+extern "C" JNIEXPORT jobjectArray JNICALL Java_Main_getThreadGroupChildren(
+    JNIEnv* env, jclass Main_klass ATTRIBUTE_UNUSED, jthreadGroup group) {
+  jint thread_count;
+  jthread* threads;
+  jint threadgroup_count;
+  jthreadGroup* groups;
+
+  jvmtiError result = jvmti_env->GetThreadGroupChildren(group,
+                                                        &thread_count,
+                                                        &threads,
+                                                        &threadgroup_count,
+                                                        &groups);
+  if (JvmtiErrorToException(env, result)) {
+    return nullptr;
+  }
+
+  auto callback = [&](jint component_index) -> jobject {
+    if (component_index == 0) {
+      // Threads.
+      auto inner_callback = [&](jint index) {
+        return threads[index];
+      };
+      return CreateObjectArray(env, thread_count, "java/lang/Thread", inner_callback);
+    } else {
+      // Groups.
+      auto inner_callback = [&](jint index) {
+        return groups[index];
+      };
+      return CreateObjectArray(env, threadgroup_count, "java/lang/ThreadGroup", inner_callback);
+    }
+  };
+  jobjectArray ret = CreateObjectArray(env, 2, "java/lang/Object", callback);
+
+  jvmti_env->Deallocate(reinterpret_cast<unsigned char*>(threads));
+  jvmti_env->Deallocate(reinterpret_cast<unsigned char*>(groups));
+
+  return ret;
+}
+
+}  // namespace Test925ThreadGroups
+}  // namespace art
diff --git a/test/Android.bp b/test/Android.bp
index b0f0e5a..00c2a68 100644
--- a/test/Android.bp
+++ b/test/Android.bp
@@ -265,6 +265,7 @@
         "922-properties/properties.cc",
         "923-monitors/monitors.cc",
         "924-threads/threads.cc",
+        "925-threadgroups/threadgroups.cc",
     ],
     shared_libs: [
         "libbase",
diff --git a/test/Android.run-test.mk b/test/Android.run-test.mk
index dd7876f..a93efd2 100644
--- a/test/Android.run-test.mk
+++ b/test/Android.run-test.mk
@@ -297,6 +297,7 @@
   922-properties \
   923-monitors \
   924-threads \
+  925-threadgroups \
 
 ifneq (,$(filter target,$(TARGET_TYPES)))
   ART_TEST_KNOWN_BROKEN += $(call all-run-test-names,target,$(RUN_TYPES),$(PREBUILD_TYPES), \