1 /* 2 * Copyright (c) 2017, Google 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 #ifndef SHARE_VM_PRIMS_JVMTIHEAPSAMPLING_HPP 26 #define SHARE_VM_PRIMS_JVMTIHEAPSAMPLING_HPP 27 28 // A RAII class that handles transitions from the agent into the VM. 29 class HeapThreadTransition : StackObj { 30 private: 31 JavaThreadState _saved_state; 32 JavaThread *_jthread; 33 34 public: 35 // Transitions this thread from the agent (thread_in_native) to the VM. 36 HeapThreadTransition(Thread *thread) { 37 if (thread->is_Java_thread()) { 38 _jthread = static_cast<JavaThread *>(thread); 39 _saved_state = _jthread->thread_state(); 40 if (_saved_state == _thread_in_native) { 41 ThreadStateTransition::transition_from_native(_jthread, _thread_in_vm); 42 } else { 43 ThreadStateTransition::transition(_jthread, 44 _saved_state, 45 _thread_in_vm); 46 } 47 } else { 48 _jthread = NULL; 49 _saved_state = _thread_new; 50 } 51 } 52 53 // Transitions this thread back to the agent from the VM. 54 ~HeapThreadTransition() { 55 if (_jthread != NULL) { 56 ThreadStateTransition::transition(_jthread, _thread_in_vm, _saved_state); 57 } 58 } 59 }; 60 61 #endif // SHARE_VM_PRIMS_JVMTIHEAPSAMPLING_HPP