Mercurial > hg > graal-compiler
view src/share/vm/prims/jniFastGetField.hpp @ 2149:7e37af9d69ef
7011379: G1: overly long concurrent marking cycles
Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads.
Reviewed-by: johnc, ysr
author | tonyp |
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date | Wed, 19 Jan 2011 09:35:17 -0500 |
parents | f95d63e2154a |
children |
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/* * Copyright (c) 2004, 2010, 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_PRIMS_JNIFASTGETFIELD_HPP #define SHARE_VM_PRIMS_JNIFASTGETFIELD_HPP #include "memory/allocation.hpp" #include "prims/jvm_misc.hpp" // Basic logic of a fast version of jni_Get<Primitive>Field: // // (See safepoint.hpp for a description of _safepoint_counter) // // load _safepoint_counter into old_counter // IF old_counter is odd THEN // a safepoint is going on, return jni_GetXXXField // ELSE // load the primitive field value into result (speculatively) // load _safepoint_counter into new_counter // IF (old_counter == new_counter) THEN // no safepoint happened during the field access, return result // ELSE // a safepoint might have happened in-between, return jni_GetXXXField() // ENDIF // ENDIF // // LoadLoad membars to maintain the load order may be necessary // for some platforms. // // The fast versions don't check for pending suspension request. // This is fine since it's totally read-only and doesn't create new race. // // There is a hypothetical safepoint counter wraparound. But it's not // a practical concern. class JNI_FastGetField : AllStatic { private: enum { LIST_CAPACITY = 40 }; // a conservative number for the number of // speculative loads on all the platforms static address speculative_load_pclist []; static address slowcase_entry_pclist []; static int count; static address generate_fast_get_int_field0(BasicType type); static address generate_fast_get_float_field0(BasicType type); public: #if defined(_WINDOWS) && !defined(_WIN64) static GetBooleanField_t jni_fast_GetBooleanField_fp; static GetByteField_t jni_fast_GetByteField_fp; static GetCharField_t jni_fast_GetCharField_fp; static GetShortField_t jni_fast_GetShortField_fp; static GetIntField_t jni_fast_GetIntField_fp; static GetLongField_t jni_fast_GetLongField_fp; static GetFloatField_t jni_fast_GetFloatField_fp; static GetDoubleField_t jni_fast_GetDoubleField_fp; #endif static address generate_fast_get_boolean_field(); static address generate_fast_get_byte_field(); static address generate_fast_get_char_field(); static address generate_fast_get_short_field(); static address generate_fast_get_int_field(); static address generate_fast_get_long_field(); static address generate_fast_get_float_field(); static address generate_fast_get_double_field(); // If pc is in speculative_load_pclist, return the corresponding // slow case entry pc. Otherwise, return -1. // This is used by signal/exception handler to handle such case: // After an even safepoint counter is loaded and a fast field access // is about to begin, a GC kicks in and shrinks the heap. Then the // field access may fault. The signal/exception handler needs to // return to the slow case. // // The GC may decide to temporarily stuff some bad values into handles, // for example, for debugging purpose, in which case we need the mapping also. static address find_slowcase_pc(address pc); }; #endif // SHARE_VM_PRIMS_JNIFASTGETFIELD_HPP