1 /*
   2  * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jni.h"
  27 #include "classfile/javaClasses.hpp"
  28 #include "classfile/symbolTable.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "jfr/jni/jfrJavaSupport.hpp"
  31 #include "jfr/recorder/jfrRecorder.hpp"
  32 #include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
  33 #include "jfr/recorder/service/jfrRecorderThread.hpp"
  34 #include "memory/resourceArea.hpp"
  35 #include "runtime/handles.inline.hpp"
  36 #include "runtime/mutexLocker.hpp"
  37 #include "runtime/thread.inline.hpp"
  38 #include "utilities/preserveException.hpp"
  39 #include "utilities/macros.hpp"
  40 
  41 static Thread* start_thread(instanceHandle thread_oop, ThreadFunction proc, TRAPS) {
  42   assert(thread_oop.not_null(), "invariant");
  43   assert(proc != NULL, "invariant");
  44 
  45   bool allocation_failed = false;
  46   JavaThread* new_thread = NULL;
  47   {
  48     MutexLocker mu(Threads_lock);
  49     new_thread = new JavaThread(proc);
  50     // At this point it may be possible that no
  51     // osthread was created for the JavaThread due to lack of memory.
  52     if (new_thread == NULL || new_thread->osthread() == NULL) {
  53       delete new_thread;
  54       allocation_failed = true;
  55     } else {
  56       java_lang_Thread::set_thread(thread_oop(), new_thread);
  57       java_lang_Thread::set_priority(thread_oop(), NormPriority);
  58       java_lang_Thread::set_daemon(thread_oop());
  59       new_thread->set_threadObj(thread_oop());
  60       Threads::add(new_thread);
  61     }
  62   }
  63   if (allocation_failed) {
  64     JfrJavaSupport::throw_out_of_memory_error("Unable to create native recording thread for JFR", CHECK_NULL);
  65   }
  66 
  67   Thread::start(new_thread);
  68   return new_thread;
  69 }
  70 
  71 JfrPostBox* JfrRecorderThread::_post_box = NULL;
  72 
  73 JfrPostBox& JfrRecorderThread::post_box() {
  74   return *_post_box;
  75 }
  76 
  77 // defined in JfrRecorderThreadLoop.cpp
  78 void recorderthread_entry(JavaThread*, Thread*);
  79 
  80 bool JfrRecorderThread::start(JfrCheckpointManager* cp_manager, JfrPostBox* post_box, TRAPS) {
  81   assert(cp_manager != NULL, "invariant");
  82   assert(post_box != NULL, "invariant");
  83   _post_box = post_box;
  84 
  85   static const char klass[] = "jdk/jfr/internal/JVMUpcalls";
  86   static const char method[] = "createRecorderThread";
  87   static const char signature[] = "(Ljava/lang/ThreadGroup;Ljava/lang/ClassLoader;)Ljava/lang/Thread;";
  88 
  89   JavaValue result(T_OBJECT);
  90   JfrJavaArguments create_thread_args(&result, klass, method, signature, CHECK_false);
  91 
  92   // arguments
  93   create_thread_args.push_oop(Universe::system_thread_group());
  94   create_thread_args.push_oop(SystemDictionary::java_system_loader());
  95 
  96   JfrJavaSupport::call_static(&create_thread_args, CHECK_false);
  97   instanceHandle h_thread_oop(THREAD, (instanceOop)result.get_jobject());
  98   assert(h_thread_oop.not_null(), "invariant");
  99   // attempt thread start
 100   const Thread* const t = start_thread(h_thread_oop, recorderthread_entry,THREAD);
 101   if (!HAS_PENDING_EXCEPTION) {
 102     cp_manager->register_service_thread(t);
 103     return true;
 104   }
 105   assert(HAS_PENDING_EXCEPTION, "invariant");
 106   // Start failed, remove the thread from the system thread group
 107   JavaValue void_result(T_VOID);
 108   JfrJavaArguments remove_thread_args(&void_result);
 109   remove_thread_args.set_klass(SystemDictionary::ThreadGroup_klass());
 110   remove_thread_args.set_name(vmSymbols::remove_method_name());
 111   remove_thread_args.set_signature(vmSymbols::thread_void_signature());
 112   remove_thread_args.set_receiver(Universe::system_thread_group());
 113   remove_thread_args.push_oop(h_thread_oop());
 114   CautiouslyPreserveExceptionMark cpe(THREAD);
 115   JfrJavaSupport::call_special(&remove_thread_args, THREAD);
 116   return false;
 117 }