ART: Add Agent Thread API

Add support for RunAgentThread. Add test.

Bug: 31684593
Test: m test-art-host-run-test-931-agent-thread
Change-Id: I5deb213fb06eedc5ee78a340458cf0dff615d0ac
diff --git a/test/931-agent-thread/agent_thread.cc b/test/931-agent-thread/agent_thread.cc
new file mode 100644
index 0000000..6ace4ce
--- /dev/null
+++ b/test/931-agent-thread/agent_thread.cc
@@ -0,0 +1,132 @@
+/*
+ * 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 <inttypes.h>
+
+#include "barrier.h"
+#include "base/logging.h"
+#include "base/macros.h"
+#include "jni.h"
+#include "openjdkjvmti/jvmti.h"
+#include "runtime.h"
+#include "ScopedLocalRef.h"
+#include "thread-inl.h"
+#include "well_known_classes.h"
+
+#include "ti-agent/common_helper.h"
+#include "ti-agent/common_load.h"
+
+namespace art {
+namespace Test930AgentThread {
+
+struct AgentData {
+  AgentData() : main_thread(nullptr),
+                jvmti_env(nullptr),
+                b(2) {
+  }
+
+  jthread main_thread;
+  jvmtiEnv* jvmti_env;
+  Barrier b;
+  jint priority;
+};
+
+static void AgentMain(jvmtiEnv* jenv, JNIEnv* env, void* arg) {
+  AgentData* data = reinterpret_cast<AgentData*>(arg);
+
+  // Check some basics.
+  // This thread is not the main thread.
+  jthread this_thread;
+  jvmtiError this_thread_result = jenv->GetCurrentThread(&this_thread);
+  CHECK(!JvmtiErrorToException(env, this_thread_result));
+  CHECK(!env->IsSameObject(this_thread, data->main_thread));
+
+  // The thread is a daemon.
+  jvmtiThreadInfo info;
+  jvmtiError info_result = jenv->GetThreadInfo(this_thread, &info);
+  CHECK(!JvmtiErrorToException(env, info_result));
+  CHECK(info.is_daemon);
+
+  // The thread has the requested priority.
+  // TODO: Our thread priorities do not work on the host.
+  // CHECK_EQ(info.priority, data->priority);
+
+  // Check further parts of the thread:
+  jint thread_count;
+  jthread* threads;
+  jvmtiError threads_result = jenv->GetAllThreads(&thread_count, &threads);
+  CHECK(!JvmtiErrorToException(env, threads_result));
+  bool found = false;
+  for (jint i = 0; i != thread_count; ++i) {
+    if (env->IsSameObject(threads[i], this_thread)) {
+      found = true;
+      break;
+    }
+  }
+  CHECK(found);
+
+  // Done, let the main thread progress.
+  data->b.Pass(Thread::Current());
+}
+
+extern "C" JNIEXPORT void JNICALL Java_Main_testAgentThread(
+    JNIEnv* env, jclass Main_klass ATTRIBUTE_UNUSED) {
+  // Create a Thread object.
+  ScopedLocalRef<jobject> thread_name(env,
+                                      env->NewStringUTF("Agent Thread"));
+  if (thread_name.get() == nullptr) {
+    return;
+  }
+
+  ScopedLocalRef<jobject> thread(env, env->AllocObject(WellKnownClasses::java_lang_Thread));
+  if (thread.get() == nullptr) {
+    return;
+  }
+
+  env->CallNonvirtualVoidMethod(thread.get(),
+                                WellKnownClasses::java_lang_Thread,
+                                WellKnownClasses::java_lang_Thread_init,
+                                Runtime::Current()->GetMainThreadGroup(),
+                                thread_name.get(),
+                                kMinThreadPriority,
+                                JNI_FALSE);
+  if (env->ExceptionCheck()) {
+    return;
+  }
+
+  jthread main_thread;
+  jvmtiError main_thread_result = jvmti_env->GetCurrentThread(&main_thread);
+  if (JvmtiErrorToException(env, main_thread_result)) {
+    return;
+  }
+
+  AgentData data;
+  data.main_thread = env->NewGlobalRef(main_thread);
+  data.jvmti_env = jvmti_env;
+  data.priority = JVMTI_THREAD_MIN_PRIORITY;
+
+  jvmtiError result = jvmti_env->RunAgentThread(thread.get(), AgentMain, &data, data.priority);
+  if (JvmtiErrorToException(env, result)) {
+    return;
+  }
+
+  data.b.Wait(Thread::Current());
+
+  env->DeleteGlobalRef(data.main_thread);
+}
+
+}  // namespace Test930AgentThread
+}  // namespace art