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/runtime/openjdkjvmti/ti_thread.cc b/runtime/openjdkjvmti/ti_thread.cc
new file mode 100644
index 0000000..04a5383
--- /dev/null
+++ b/runtime/openjdkjvmti/ti_thread.cc
@@ -0,0 +1,202 @@
+/* Copyright (C) 2017 The Android Open Source Project
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This file implements interfaces from the file jvmti.h. This implementation
+ * is licensed under the same terms as the file jvmti.h. The
+ * copyright and license information for the file jvmti.h follows.
+ *
+ * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include "ti_thread.h"
+
+#include "art_field.h"
+#include "art_jvmti.h"
+#include "base/logging.h"
+#include "base/mutex.h"
+#include "jni_internal.h"
+#include "mirror/class.h"
+#include "mirror/object-inl.h"
+#include "mirror/string.h"
+#include "obj_ptr.h"
+#include "scoped_thread_state_change-inl.h"
+#include "thread-inl.h"
+#include "well_known_classes.h"
+
+namespace openjdkjvmti {
+
+jvmtiError ThreadUtil::GetCurrentThread(jvmtiEnv* env ATTRIBUTE_UNUSED, jthread* thread_ptr) {
+ art::Thread* self = art::Thread::Current();
+
+ art::ScopedObjectAccess soa(self);
+
+ jthread thread_peer;
+ if (self->IsStillStarting()) {
+ thread_peer = nullptr;
+ } else {
+ thread_peer = soa.AddLocalReference<jthread>(self->GetPeer());
+ }
+
+ *thread_ptr = thread_peer;
+ return ERR(NONE);
+}
+
+// Read the context classloader from a Java thread object. This is a lazy implementation
+// that assumes GetThreadInfo isn't called too often. If we instead cache the ArtField,
+// we will have to add synchronization as this can't be cached on startup (which is
+// potentially runtime startup).
+static art::ObjPtr<art::mirror::Object> GetContextClassLoader(art::ObjPtr<art::mirror::Object> peer)
+ REQUIRES_SHARED(art::Locks::mutator_lock_) {
+ if (peer == nullptr) {
+ return nullptr;
+ }
+ art::ObjPtr<art::mirror::Class> klass = peer->GetClass();
+ art::ArtField* cc_field = klass->FindDeclaredInstanceField("contextClassLoader",
+ "Ljava/lang/ClassLoader;");
+ CHECK(cc_field != nullptr);
+ return cc_field->GetObject(peer);
+}
+
+// Get the native thread. The spec says a null object denotes the current thread.
+static art::Thread* GetNativeThread(jthread thread,
+ const art::ScopedObjectAccessAlreadyRunnable& soa)
+ REQUIRES_SHARED(art::Locks::mutator_lock_) {
+ if (thread == nullptr) {
+ return art::Thread::Current();
+ }
+
+ art::MutexLock mu(soa.Self(), *art::Locks::thread_list_lock_);
+ return art::Thread::FromManagedThread(soa, thread);
+}
+
+jvmtiError ThreadUtil::GetThreadInfo(jvmtiEnv* env, jthread thread, jvmtiThreadInfo* info_ptr) {
+ if (info_ptr == nullptr) {
+ return ERR(NULL_POINTER);
+ }
+
+ art::ScopedObjectAccess soa(art::Thread::Current());
+
+ art::Thread* self = GetNativeThread(thread, soa);
+ if (self == nullptr && thread == nullptr) {
+ return ERR(INVALID_THREAD);
+ }
+
+ JvmtiUniquePtr name_uptr;
+ if (self != nullptr) {
+ // Have a native thread object, this thread is alive.
+ std::string name;
+ self->GetThreadName(name);
+ jvmtiError name_result = CopyString(
+ env, name.c_str(), reinterpret_cast<unsigned char**>(&info_ptr->name));
+ if (name_result != ERR(NONE)) {
+ return name_result;
+ }
+ name_uptr = MakeJvmtiUniquePtr(env, info_ptr->name);
+
+ info_ptr->priority = self->GetNativePriority();
+
+ info_ptr->is_daemon = self->IsDaemon();
+
+ art::ObjPtr<art::mirror::Object> peer = self->GetPeer();
+
+ // ThreadGroup.
+ if (peer != nullptr) {
+ art::ArtField* f = art::jni::DecodeArtField(art::WellKnownClasses::java_lang_Thread_group);
+ CHECK(f != nullptr);
+ art::ObjPtr<art::mirror::Object> group = f->GetObject(peer);
+ info_ptr->thread_group = group == nullptr
+ ? nullptr
+ : soa.AddLocalReference<jthreadGroup>(group);
+ } else {
+ info_ptr->thread_group = nullptr;
+ }
+
+ // Context classloader.
+ art::ObjPtr<art::mirror::Object> ccl = GetContextClassLoader(peer);
+ info_ptr->context_class_loader = ccl == nullptr
+ ? nullptr
+ : soa.AddLocalReference<jobject>(ccl);
+ } else {
+ // Only the peer. This thread has either not been started, or is dead. Read things from
+ // the Java side.
+ art::ObjPtr<art::mirror::Object> peer = soa.Decode<art::mirror::Object>(thread);
+
+ // Name.
+ {
+ art::ArtField* f = art::jni::DecodeArtField(art::WellKnownClasses::java_lang_Thread_name);
+ CHECK(f != nullptr);
+ art::ObjPtr<art::mirror::Object> name = f->GetObject(peer);
+ std::string name_cpp;
+ const char* name_cstr;
+ if (name != nullptr) {
+ name_cpp = name->AsString()->ToModifiedUtf8();
+ name_cstr = name_cpp.c_str();
+ } else {
+ name_cstr = "";
+ }
+ jvmtiError name_result = CopyString(
+ env, name_cstr, reinterpret_cast<unsigned char**>(&info_ptr->name));
+ if (name_result != ERR(NONE)) {
+ return name_result;
+ }
+ name_uptr = MakeJvmtiUniquePtr(env, info_ptr->name);
+ }
+
+ // Priority.
+ {
+ art::ArtField* f = art::jni::DecodeArtField(art::WellKnownClasses::java_lang_Thread_priority);
+ CHECK(f != nullptr);
+ info_ptr->priority = static_cast<jint>(f->GetInt(peer));
+ }
+
+ // Daemon.
+ {
+ art::ArtField* f = art::jni::DecodeArtField(art::WellKnownClasses::java_lang_Thread_daemon);
+ CHECK(f != nullptr);
+ info_ptr->is_daemon = f->GetBoolean(peer) == 0 ? JNI_FALSE : JNI_TRUE;
+ }
+
+ // ThreadGroup.
+ {
+ art::ArtField* f = art::jni::DecodeArtField(art::WellKnownClasses::java_lang_Thread_group);
+ CHECK(f != nullptr);
+ art::ObjPtr<art::mirror::Object> group = f->GetObject(peer);
+ info_ptr->thread_group = group == nullptr
+ ? nullptr
+ : soa.AddLocalReference<jthreadGroup>(group);
+ }
+
+ // Context classloader.
+ art::ObjPtr<art::mirror::Object> ccl = GetContextClassLoader(peer);
+ info_ptr->context_class_loader = ccl == nullptr
+ ? nullptr
+ : soa.AddLocalReference<jobject>(ccl);
+ }
+
+ name_uptr.release();
+
+ return ERR(NONE);
+}
+
+} // namespace openjdkjvmti