Mercurial > hg > graal-compiler
view src/share/vm/runtime/rtmLocking.hpp @ 20806:6ee9b878902b
Fix merge mess-ups
author | Gilles Duboscq <gilles.m.duboscq@oracle.com> |
---|---|
date | Tue, 07 Apr 2015 18:57:02 +0200 |
parents | 606acabe7b5c |
children |
line wrap: on
line source
/* * Copyright (c) 2014, 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. * * 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. * */ #ifndef SHARE_VM_RUNTIME_RTMLOCKING_HPP #define SHARE_VM_RUNTIME_RTMLOCKING_HPP // Generate RTM (Restricted Transactional Memory) locking code for all inflated // locks when "UseRTMLocking" option is on with normal locking mechanism as fall back // handler. // // On abort/lock busy the lock will be retried a fixed number of times under RTM // as specified by "RTMRetryCount" option. The locks which abort too often // can be auto tuned or manually tuned. // // Auto-tuning can be done on an option like UseRTMDeopt and it will need abort // ratio calculation for each lock. The abort ratio will be calculated after // "RTMAbortThreshold" number of aborts is reached. The formulas are: // // Aborted transactions = abort_count * 100 // All transactions = total_count * RTMTotalCountIncrRate // // Aborted transactions >= All transactions * RTMAbortRatio // // If "UseRTMDeopt" is on and the aborts ratio reaches "RTMAbortRatio" // the method containing the lock will be deoptimized and recompiled with // all locks as normal locks. If the abort ratio continues to remain low after // "RTMLockingThreshold" locks are attempted, then the method will be deoptimized // and recompiled with all locks as RTM locks without abort ratio calculation code. // The abort ratio calculation can be delayed by specifying flag // -XX:RTMLockingCalculationDelay in millisecond. // // For manual tuning the abort statistics for each lock needs to be provided // to the user on some JVM option like "PrintPreciseRTMLockingStatistics". // Based on the abort statistics users can create a .hotspot_compiler file // or use -XX:CompileCommand=option,class::method,NoRTMLockEliding // to specify for which methods to disable RTM locking. // // When UseRTMForStackLocks option is enabled along with UseRTMLocking option, // the RTM locking code is generated for stack locks too. // The retries, auto-tuning support and rtm locking statistics are all // supported for stack locks just like inflated locks. // RTM locking counters class RTMLockingCounters VALUE_OBJ_CLASS_SPEC { private: uintx _total_count; // Total RTM locks count uintx _abort_count; // Total aborts count public: enum { ABORT_STATUS_LIMIT = 6 }; // Counters per RTM Abort Status. Incremented with +PrintPreciseRTMLockingStatistics // RTM uses the EAX register to communicate abort status to software. // Following an RTM abort the EAX register has the following definition. // // EAX register bit position Meaning // 0 Set if abort caused by XABORT instruction. // 1 If set, the transaction may succeed on a retry. This bit is always clear if bit 0 is set. // 2 Set if another logical processor conflicted with a memory address that was part of the transaction that aborted. // 3 Set if an internal buffer overflowed. // 4 Set if a debug breakpoint was hit. // 5 Set if an abort occurred during execution of a nested transaction. private: uintx _abortX_count[ABORT_STATUS_LIMIT]; public: static uintx _calculation_flag; static uintx* rtm_calculation_flag_addr() { return &_calculation_flag; } static void init(); RTMLockingCounters() : _total_count(0), _abort_count(0) { for (int i = 0; i < ABORT_STATUS_LIMIT; i++) { _abortX_count[i] = 0; } } uintx* total_count_addr() { return &_total_count; } uintx* abort_count_addr() { return &_abort_count; } uintx* abortX_count_addr() { return &_abortX_count[0]; } static int total_count_offset() { return (int)offset_of(RTMLockingCounters, _total_count); } static int abort_count_offset() { return (int)offset_of(RTMLockingCounters, _abort_count); } static int abortX_count_offset() { return (int)offset_of(RTMLockingCounters, _abortX_count[0]); } bool nonzero() { return (_abort_count + _total_count) > 0; } void print_on(outputStream* st); void print() { print_on(tty); } }; #endif // SHARE_VM_RUNTIME_RTMLOCKING_HPP