| /* |
| * Copyright (c) 1997, 2017, 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 count() > limit(). |
| |
| class InvocationCounter VALUE_OBJ_CLASS_SPEC { |
| friend class VMStructs; |
| friend class JVMCIVMStructs; |
| 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, |
| 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)(const 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, |
| number_of_count_bits = BitsPerInt - 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; } |
| |
| #ifdef CC_INTERP |
| // Test counter using scaled limits like the asm interpreter would do rather than doing |
| // the shifts to normalize the counter. |
| // Checks sum of invocation_counter and backedge_counter as the template interpreter does. |
| bool reached_InvocationLimit(InvocationCounter *back_edge_count) const { |
| return (_counter & count_mask) + (back_edge_count->_counter & count_mask) >= |
| (unsigned int) InterpreterInvocationLimit; |
| } |
| bool reached_BackwardBranchLimit(InvocationCounter *back_edge_count) const { |
| return (_counter & count_mask) + (back_edge_count->_counter & count_mask) >= |
| (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 & count_mask) >= |
| (unsigned int) InterpreterProfileLimit; |
| } |
| #endif // CC_INTERP |
| |
| 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 |