1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/interpreter/invocationCounter.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,137 @@
1.4 +/*
1.5 + * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +// InvocationCounters are used to trigger actions when a limit (threshold) is reached.
1.29 +// For different states, different limits and actions can be defined in the initialization
1.30 +// routine of InvocationCounters.
1.31 +//
1.32 +// Implementation notes: For space reasons, state & counter are both encoded in one word,
1.33 +// The state is encoded using some of the least significant bits, the counter is using the
1.34 +// more significant bits. The counter is incremented before a method is activated and an
1.35 +// action is triggered when when count() > limit().
1.36 +
1.37 +class InvocationCounter VALUE_OBJ_CLASS_SPEC {
1.38 + friend class VMStructs;
1.39 + private: // bit no: |31 3| 2 | 1 0 |
1.40 + unsigned int _counter; // format: [count|carry|state]
1.41 +
1.42 + enum PrivateConstants {
1.43 + number_of_state_bits = 2,
1.44 + number_of_carry_bits = 1,
1.45 + number_of_noncount_bits = number_of_state_bits + number_of_carry_bits,
1.46 + number_of_count_bits = BitsPerInt - number_of_noncount_bits,
1.47 + state_limit = nth_bit(number_of_state_bits),
1.48 + count_grain = nth_bit(number_of_state_bits + number_of_carry_bits),
1.49 + count_limit = nth_bit(number_of_count_bits - 1),
1.50 + carry_mask = right_n_bits(number_of_carry_bits) << number_of_state_bits,
1.51 + state_mask = right_n_bits(number_of_state_bits),
1.52 + status_mask = right_n_bits(number_of_state_bits + number_of_carry_bits),
1.53 + count_mask = ((int)(-1) ^ status_mask)
1.54 + };
1.55 +
1.56 + public:
1.57 + static int InterpreterInvocationLimit; // CompileThreshold scaled for interpreter use
1.58 + static int Tier1InvocationLimit; // CompileThreshold scaled for tier1 use
1.59 + static int Tier1BackEdgeLimit; // BackEdgeThreshold scaled for tier1 use
1.60 +
1.61 + static int InterpreterBackwardBranchLimit; // A separate threshold for on stack replacement
1.62 +
1.63 + static int InterpreterProfileLimit; // Profiling threshold scaled for interpreter use
1.64 +
1.65 + typedef address (*Action)(methodHandle method, TRAPS);
1.66 +
1.67 + enum PublicConstants {
1.68 + count_increment = count_grain, // use this value to increment the 32bit _counter word
1.69 + count_mask_value = count_mask // use this value to mask the backedge counter
1.70 + };
1.71 +
1.72 + enum State {
1.73 + wait_for_nothing, // do nothing when count() > limit()
1.74 + wait_for_compile, // introduce nmethod when count() > limit()
1.75 + number_of_states // must be <= state_limit
1.76 + };
1.77 +
1.78 + // Manipulation
1.79 + void reset(); // sets state to wait state
1.80 + void init(); // sets state into original state
1.81 + void set_state(State state); // sets state and initializes counter correspondingly
1.82 + inline void set(State state, int count); // sets state and counter
1.83 + inline void decay(); // decay counter (divide by two)
1.84 + void set_carry(); // set the sticky carry bit
1.85 +
1.86 + // Accessors
1.87 + State state() const { return (State)(_counter & state_mask); }
1.88 + bool carry() const { return (_counter & carry_mask) != 0; }
1.89 + int limit() const { return CompileThreshold; }
1.90 + Action action() const { return _action[state()]; }
1.91 + int count() const { return _counter >> number_of_noncount_bits; }
1.92 +
1.93 + int get_InvocationLimit() const { return InterpreterInvocationLimit >> number_of_noncount_bits; }
1.94 + int get_BackwardBranchLimit() const { return InterpreterBackwardBranchLimit >> number_of_noncount_bits; }
1.95 + int get_ProfileLimit() const { return InterpreterProfileLimit >> number_of_noncount_bits; }
1.96 +
1.97 + // Test counter using scaled limits like the asm interpreter would do rather than doing
1.98 + // the shifts to normalize the counter.
1.99 +
1.100 + bool reached_InvocationLimit() const { return _counter >= (unsigned int) InterpreterInvocationLimit; }
1.101 + bool reached_BackwardBranchLimit() const { return _counter >= (unsigned int) InterpreterBackwardBranchLimit; }
1.102 +
1.103 + // Do this just like asm interpreter does for max speed
1.104 + bool reached_ProfileLimit(InvocationCounter *back_edge_count) const {
1.105 + return (_counter && count_mask) + back_edge_count->_counter >= (unsigned int) InterpreterProfileLimit;
1.106 + }
1.107 +
1.108 + void increment() { _counter += count_increment; }
1.109 +
1.110 +
1.111 + // Printing
1.112 + void print();
1.113 + void print_short();
1.114 +
1.115 + // Miscellaneous
1.116 + static ByteSize counter_offset() { return byte_offset_of(InvocationCounter, _counter); }
1.117 + static void reinitialize(bool delay_overflow);
1.118 +
1.119 + private:
1.120 + static int _init [number_of_states]; // the counter limits
1.121 + static Action _action[number_of_states]; // the actions
1.122 +
1.123 + static void def(State state, int init, Action action);
1.124 + static const char* state_as_string(State state);
1.125 + static const char* state_as_short_string(State state);
1.126 +};
1.127 +
1.128 +inline void InvocationCounter::set(State state, int count) {
1.129 + assert(0 <= state && state < number_of_states, "illegal state");
1.130 + int carry = (_counter & carry_mask); // the carry bit is sticky
1.131 + _counter = (count << number_of_noncount_bits) | carry | state;
1.132 +}
1.133 +
1.134 +inline void InvocationCounter::decay() {
1.135 + int c = count();
1.136 + int new_count = c >> 1;
1.137 + // prevent from going to zero, to distinguish from never-executed methods
1.138 + if (c > 0 && new_count == 0) new_count = 1;
1.139 + set(state(), new_count);
1.140 +}
