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 #include "precompiled.hpp" 26 #include "logging/log.hpp" 27 #include "runtime/globals.hpp" 28 #include "runtime/os.hpp" 29 #include "runtime/safepointMechanism.inline.hpp" 30 #include "utilities/globalDefinitions.hpp" 31 32 SafepointMechanism::PollingType SafepointMechanism::_polling_type = SafepointMechanism::_global_page_poll; 33 void* SafepointMechanism::_poll_armed_value; 34 void* SafepointMechanism::_poll_disarmed_value; 35 36 void SafepointMechanism::default_initialize() { 37 if (ThreadLocalHandshakes) { 38 set_uses_thread_local_poll(); 39 const size_t page_size = os::vm_page_size(); 40 const size_t allocation_size = 2 * page_size; 41 char* polling_page = os::reserve_memory(allocation_size, NULL, page_size); 42 os::commit_memory_or_exit(polling_page, allocation_size, false, "Unable to commit Safepoint polling page"); 43 44 char* bad_page = polling_page; 45 char* good_page = polling_page + page_size; 46 47 os::protect_memory(bad_page, page_size, os::MEM_PROT_NONE); 48 os::protect_memory(good_page, page_size, os::MEM_PROT_READ); 49 50 log_info(os)("SafePoint Polling address, bad (protected) page:" INTPTR_FORMAT ", good (unprotected) page:" INTPTR_FORMAT, p2i(bad_page), p2i(good_page)); 51 os::set_polling_page((address)(bad_page)); 52 53 intptr_t poll_page_val = reinterpret_cast<intptr_t>(bad_page); 54 _poll_armed_value = reinterpret_cast<void*>(poll_page_val | poll_bit()); 55 _poll_disarmed_value = good_page; 56 } else { 57 const size_t page_size = os::vm_page_size(); 58 char* polling_page = os::reserve_memory(page_size, NULL, page_size); 59 os::commit_memory_or_exit(polling_page, page_size, false, "Unable to commit Safepoint polling page"); 60 os::protect_memory(polling_page, page_size, os::MEM_PROT_READ); 61 62 log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page)); 63 os::set_polling_page((address)(polling_page)); 64 } 65 } 66 67 void SafepointMechanism::initialize_header(JavaThread* thread) { 68 disarm_local_poll(thread); 69 } 70 71 void SafepointMechanism::initialize_serialize_page() { 72 if (!UseMembar) { 73 const size_t page_size = os::vm_page_size(); 74 char* serialize_page = os::reserve_memory(page_size, NULL, page_size); 75 os::commit_memory_or_exit(serialize_page, page_size, false, "Unable to commit memory serialization page"); 76 log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(serialize_page)); 77 os::set_memory_serialize_page((address)(serialize_page)); 78 } 79 } 80 81 void SafepointMechanism::initialize() { 82 pd_initialize(); 83 initialize_serialize_page(); 84 }