ART: Add GetCurrentThread and GetThreadInfo

Add support for GetCurrentThread and GetThreadInfo. Add tests.

Bug: 31684593
Test: m test-art-host-run-test-924-threads
Change-Id: Ic2bc4c9b5c283e4eefe4075b6abe251b8be499c8
diff --git a/test/924-threads/threads.cc b/test/924-threads/threads.cc
new file mode 100644
index 0000000..bcd813f
--- /dev/null
+++ b/test/924-threads/threads.cc
@@ -0,0 +1,108 @@
+/*
+ * 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 "threads.h"
+
+#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 Test924Threads {
+
+// private static native Thread getCurrentThread();
+// private static native Object[] getThreadInfo(Thread t);
+
+extern "C" JNIEXPORT jthread JNICALL Java_Main_getCurrentThread(
+    JNIEnv* env, jclass Main_klass ATTRIBUTE_UNUSED) {
+  jthread thread = nullptr;
+  jvmtiError result = jvmti_env->GetCurrentThread(&thread);
+  if (JvmtiErrorToException(env, result)) {
+    return nullptr;
+  }
+  return thread;
+}
+
+extern "C" JNIEXPORT jobjectArray JNICALL Java_Main_getThreadInfo(
+    JNIEnv* env, jclass Main_klass ATTRIBUTE_UNUSED, jthread thread) {
+  jvmtiThreadInfo info;
+  memset(&info, 0, sizeof(jvmtiThreadInfo));
+
+  jvmtiError result = jvmti_env->GetThreadInfo(thread, &info);
+  if (JvmtiErrorToException(env, result)) {
+    return nullptr;
+  }
+
+  auto callback = [&](jint component_index) -> jobject {
+    switch (component_index) {
+      // The name.
+      case 0:
+        return (info.name == nullptr) ? nullptr : env->NewStringUTF(info.name);
+
+      // The priority. Use a string for simplicity of construction.
+      case 1:
+        return env->NewStringUTF(android::base::StringPrintf("%d", info.priority).c_str());
+
+      // Whether it's a daemon. Use a string for simplicity of construction.
+      case 2:
+        return env->NewStringUTF(info.is_daemon == JNI_TRUE ? "true" : "false");
+
+      // The thread group;
+      case 3:
+        return env->NewLocalRef(info.thread_group);
+
+      // The context classloader.
+      case 4:
+        return env->NewLocalRef(info.context_class_loader);
+    }
+    LOG(FATAL) << "Should not reach here";
+    UNREACHABLE();
+  };
+  jobjectArray ret = CreateObjectArray(env, 5, "java/lang/Object", callback);
+
+  jvmti_env->Deallocate(reinterpret_cast<unsigned char*>(info.name));
+  if (info.thread_group != nullptr) {
+    env->DeleteLocalRef(info.thread_group);
+  }
+  if (info.context_class_loader != nullptr) {
+    env->DeleteLocalRef(info.context_class_loader);
+  }
+
+  return ret;
+}
+
+// Don't do anything
+jint OnLoad(JavaVM* vm,
+            char* options ATTRIBUTE_UNUSED,
+            void* reserved ATTRIBUTE_UNUSED) {
+  if (vm->GetEnv(reinterpret_cast<void**>(&jvmti_env), JVMTI_VERSION_1_0)) {
+    printf("Unable to get jvmti env!\n");
+    return 1;
+  }
+  SetAllCapabilities(jvmti_env);
+  return 0;
+}
+
+}  // namespace Test924Threads
+}  // namespace art