Mercurial > hg > truffle
view src/share/vm/interpreter/invocationCounter.hpp @ 9126:bc26f978b0ce
HotSpotResolvedObjectType: implement hasFinalizeSubclass() correctly
don't use the (wrong) cached value, but ask the runtime on each request.
Fixes regression on xml.* benchmarks @ specjvm2008. The problem was:
After the constructor of Object was deoptimized due to an assumption violation,
it was recompiled again after some time. However, on recompilation, the value
of hasFinalizeSubclass for the class was not updated and it was compiled again
with a, now wrong, assumption, which then triggers deoptimization again.
This was repeated until it hit the recompilation limit (defined by
PerMethodRecompilationCutoff), and therefore only executed by the interpreter
from now on, causing the performance regression.
author | Bernhard Urban <bernhard.urban@jku.at> |
---|---|
date | Mon, 15 Apr 2013 19:54:58 +0200 |
parents | bd7a7ce2e264 |
children | a9311ec68721 abe03600372a |
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/* * Copyright (c) 1997, 2012, 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_INTERPRETER_INVOCATIONCOUNTER_HPP #define SHARE_VM_INTERPRETER_INVOCATIONCOUNTER_HPP #include "memory/allocation.hpp" #include "runtime/handles.hpp" #include "utilities/exceptions.hpp" // InvocationCounters are used to trigger actions when a limit (threshold) is reached. // For different states, different limits and actions can be defined in the initialization // routine of InvocationCounters. // // Implementation notes: For space reasons, state & counter are both encoded in one word, // The state is encoded using some of the least significant bits, the counter is using the // more significant bits. The counter is incremented before a method is activated and an // action is triggered when when count() > limit(). class InvocationCounter VALUE_OBJ_CLASS_SPEC { friend class VMStructs; friend class ciReplay; private: // bit no: |31 3| 2 | 1 0 | unsigned int _counter; // format: [count|carry|state] enum PrivateConstants { number_of_state_bits = 2, number_of_carry_bits = 1, number_of_noncount_bits = number_of_state_bits + number_of_carry_bits, number_of_count_bits = BitsPerInt - number_of_noncount_bits, state_limit = nth_bit(number_of_state_bits), count_grain = nth_bit(number_of_state_bits + number_of_carry_bits), carry_mask = right_n_bits(number_of_carry_bits) << number_of_state_bits, state_mask = right_n_bits(number_of_state_bits), status_mask = right_n_bits(number_of_state_bits + number_of_carry_bits), count_mask = ((int)(-1) ^ status_mask) }; public: static int InterpreterInvocationLimit; // CompileThreshold scaled for interpreter use static int InterpreterBackwardBranchLimit; // A separate threshold for on stack replacement static int InterpreterProfileLimit; // Profiling threshold scaled for interpreter use typedef address (*Action)(methodHandle method, TRAPS); enum PublicConstants { count_increment = count_grain, // use this value to increment the 32bit _counter word count_mask_value = count_mask, // use this value to mask the backedge counter count_shift = number_of_noncount_bits, count_limit = nth_bit(number_of_count_bits - 1) }; enum State { wait_for_nothing, // do nothing when count() > limit() wait_for_compile, // introduce nmethod when count() > limit() number_of_states // must be <= state_limit }; // Manipulation void reset(); // sets state to wait state void init(); // sets state into original state void set_state(State state); // sets state and initializes counter correspondingly inline void set(State state, int count); // sets state and counter inline void decay(); // decay counter (divide by two) void set_carry(); // set the sticky carry bit void set_carry_flag() { _counter |= carry_mask; } int raw_counter() { return _counter; } // Accessors State state() const { return (State)(_counter & state_mask); } bool carry() const { return (_counter & carry_mask) != 0; } int limit() const { return CompileThreshold; } Action action() const { return _action[state()]; } int count() const { return _counter >> number_of_noncount_bits; } int get_InvocationLimit() const { return InterpreterInvocationLimit >> number_of_noncount_bits; } int get_BackwardBranchLimit() const { return InterpreterBackwardBranchLimit >> number_of_noncount_bits; } int get_ProfileLimit() const { return InterpreterProfileLimit >> number_of_noncount_bits; } // Test counter using scaled limits like the asm interpreter would do rather than doing // the shifts to normalize the counter. bool reached_InvocationLimit() const { return _counter >= (unsigned int) InterpreterInvocationLimit; } bool reached_BackwardBranchLimit() const { return _counter >= (unsigned int) InterpreterBackwardBranchLimit; } // Do this just like asm interpreter does for max speed bool reached_ProfileLimit(InvocationCounter *back_edge_count) const { return (_counter && count_mask) + back_edge_count->_counter >= (unsigned int) InterpreterProfileLimit; } void increment() { _counter += count_increment; } // Printing void print(); void print_short(); // Miscellaneous static ByteSize counter_offset() { return byte_offset_of(InvocationCounter, _counter); } static void reinitialize(bool delay_overflow); private: static int _init [number_of_states]; // the counter limits static Action _action[number_of_states]; // the actions static void def(State state, int init, Action action); static const char* state_as_string(State state); static const char* state_as_short_string(State state); }; inline void InvocationCounter::set(State state, int count) { assert(0 <= state && state < number_of_states, "illegal state"); int carry = (_counter & carry_mask); // the carry bit is sticky _counter = (count << number_of_noncount_bits) | carry | state; } inline void InvocationCounter::decay() { int c = count(); int new_count = c >> 1; // prevent from going to zero, to distinguish from never-executed methods if (c > 0 && new_count == 0) new_count = 1; set(state(), new_count); } #endif // SHARE_VM_INTERPRETER_INVOCATIONCOUNTER_HPP