1 /* 2 * Copyright (c) 2017, 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 #ifndef SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_INLINE_HPP 26 #define SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_INLINE_HPP 27 28 #include "runtime/safepointMechanism.hpp" 29 #include "runtime/safepoint.hpp" 30 #include "runtime/thread.inline.hpp" 31 32 bool SafepointMechanism::local_poll_armed(JavaThread* thread) { 33 const intptr_t poll_word = reinterpret_cast<intptr_t>(thread->get_polling_page()); 34 return mask_bits_are_true(poll_word, poll_bit()); 35 } 36 37 bool SafepointMechanism::global_poll() { 38 return SafepointSynchronize::do_call_back(); 39 } 40 41 bool SafepointMechanism::local_poll(Thread* thread) { 42 // Mutexes can be taken but none JavaThread. These cannot have handshakes 43 // operation but they must stop for safepoints. 44 if (thread->is_Java_thread()) { 45 return local_poll_armed((JavaThread*)thread); 46 } else { 47 return global_poll(); 48 } 49 } 50 51 bool SafepointMechanism::poll(Thread* thread) { 52 if (uses_thread_local_poll()) { 53 return local_poll(thread); 54 } else { 55 return global_poll(); 56 } 57 } 58 59 void SafepointMechanism::block_if_requested_local_poll(JavaThread *thread) { 60 bool armed = local_poll_armed(thread); // load acquire, polling page -> op / global state 61 if(armed) { 62 // We could be armed for either a handshake operation or a safepoint 63 if (thread->has_handshake()) { 64 thread->handshake_process_by_self(); 65 } else { 66 if (global_poll()) { 67 SafepointSynchronize::block(thread); 68 } 69 } 70 } 71 } 72 73 void SafepointMechanism::block_if_requested(JavaThread *thread) { 74 if (uses_thread_local_poll()) { 75 block_if_requested_local_poll(thread); 76 } else { 77 // If we don't have per thread poll this could a handshake or a safepoint 78 if (global_poll()) { 79 SafepointSynchronize::block(thread); 80 } 81 } 82 } 83 84 void SafepointMechanism::arm_local_poll(JavaThread* thread) { 85 thread->set_polling_page(poll_armed_value()); 86 } 87 88 void SafepointMechanism::disarm_local_poll(JavaThread* thread) { 89 thread->set_polling_page(poll_disarmed_value()); 90 } 91 92 #endif // SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_INLINE_HPP