Mercurial > hg > truffle
view src/share/vm/interpreter/invocationCounter.cpp @ 452:00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
Summary: When we encounter marking stack overflow during precleaning of Reference lists, we were using the overflow list mechanism, which can cause problems on account of mutating the mark word of the header because of conflicts with mutator accesses and updates of that field. Instead we should use the usual mechanism for overflow handling in concurrent phases, namely dirtying of the card on which the overflowed object lies. Since precleaning effectively does a form of discovered list processing, albeit with discovery enabled, we needed to adjust some code to be correct in the face of interleaved processing and discovery.
Reviewed-by: apetrusenko, jcoomes
author | ysr |
---|---|
date | Thu, 20 Nov 2008 12:27:41 -0800 |
parents | a61af66fc99e |
children | c664a0794f85 |
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/* * Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ # include "incls/_precompiled.incl" # include "incls/_invocationCounter.cpp.incl" // Implementation of InvocationCounter void InvocationCounter::init() { _counter = 0; // reset all the bits, including the sticky carry reset(); } void InvocationCounter::reset() { // Only reset the state and don't make the method look like it's never // been executed set_state(wait_for_compile); } void InvocationCounter::set_carry() { _counter |= carry_mask; // The carry bit now indicates that this counter had achieved a very // large value. Now reduce the value, so that the method can be // executed many more times before re-entering the VM. int old_count = count(); int new_count = MIN2(old_count, (int) (CompileThreshold / 2)); if (old_count != new_count) set(state(), new_count); } void InvocationCounter::set_state(State state) { assert(0 <= state && state < number_of_states, "illegal state"); int init = _init[state]; // prevent from going to zero, to distinguish from never-executed methods if (init == 0 && count() > 0) init = 1; int carry = (_counter & carry_mask); // the carry bit is sticky _counter = (init << number_of_noncount_bits) | carry | state; } void InvocationCounter::print() { tty->print_cr("invocation count: up = %d, limit = %d, carry = %s, state = %s", count(), limit(), carry() ? "true" : "false", state_as_string(state())); } void InvocationCounter::print_short() { tty->print(" [%d%s;%s]", count(), carry()?"+carry":"", state_as_short_string(state())); } // Initialization int InvocationCounter::_init [InvocationCounter::number_of_states]; InvocationCounter::Action InvocationCounter::_action[InvocationCounter::number_of_states]; int InvocationCounter::InterpreterInvocationLimit; int InvocationCounter::InterpreterBackwardBranchLimit; int InvocationCounter::InterpreterProfileLimit; // Tier1 limits int InvocationCounter::Tier1InvocationLimit; int InvocationCounter::Tier1BackEdgeLimit; const char* InvocationCounter::state_as_string(State state) { switch (state) { case wait_for_nothing : return "wait_for_nothing"; case wait_for_compile : return "wait_for_compile"; } ShouldNotReachHere(); return NULL; } const char* InvocationCounter::state_as_short_string(State state) { switch (state) { case wait_for_nothing : return "not comp."; case wait_for_compile : return "compileable"; } ShouldNotReachHere(); return NULL; } static address do_nothing(methodHandle method, TRAPS) { // dummy action for inactive invocation counters method->invocation_counter()->set_carry(); method->invocation_counter()->set_state(InvocationCounter::wait_for_nothing); return NULL; } static address do_decay(methodHandle method, TRAPS) { // decay invocation counters so compilation gets delayed method->invocation_counter()->decay(); return NULL; } void InvocationCounter::def(State state, int init, Action action) { assert(0 <= state && state < number_of_states, "illegal state"); assert(0 <= init && init < count_limit, "initial value out of range"); _init [state] = init; _action[state] = action; } address dummy_invocation_counter_overflow(methodHandle m, TRAPS) { ShouldNotReachHere(); return NULL; } void InvocationCounter::reinitialize(bool delay_overflow) { // define states guarantee((int)number_of_states <= (int)state_limit, "adjust number_of_state_bits"); def(wait_for_nothing, 0, do_nothing); if (delay_overflow) { def(wait_for_compile, 0, do_decay); } else { def(wait_for_compile, 0, dummy_invocation_counter_overflow); } InterpreterInvocationLimit = CompileThreshold << number_of_noncount_bits; InterpreterProfileLimit = ((CompileThreshold * InterpreterProfilePercentage) / 100)<< number_of_noncount_bits; Tier1InvocationLimit = Tier2CompileThreshold << number_of_noncount_bits; Tier1BackEdgeLimit = Tier2BackEdgeThreshold << number_of_noncount_bits; // When methodData is collected, the backward branch limit is compared against a // methodData counter, rather than an InvocationCounter. In the former case, we // don't need the shift by number_of_noncount_bits, but we do need to adjust // the factor by which we scale the threshold. if (ProfileInterpreter) { InterpreterBackwardBranchLimit = (CompileThreshold * (OnStackReplacePercentage - InterpreterProfilePercentage)) / 100; } else { InterpreterBackwardBranchLimit = ((CompileThreshold * OnStackReplacePercentage) / 100) << number_of_noncount_bits; } assert(0 <= InterpreterBackwardBranchLimit, "OSR threshold should be non-negative"); assert(0 <= InterpreterProfileLimit && InterpreterProfileLimit <= InterpreterInvocationLimit, "profile threshold should be less than the compilation threshold " "and non-negative"); } void invocationCounter_init() { InvocationCounter::reinitialize(DelayCompilationDuringStartup); }