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src/share/vm/interpreter/invocationCounter.hpp@43f9d800f276 (annotated)

src/share/vm/interpreter/invocationCounter.hpp

Wed, 20 Jul 2011 18:04:17 -0700

author

iveresov

date

Wed, 20 Jul 2011 18:04:17 -0700

changeset 3035

43f9d800f276

parent 2314

f95d63e2154a

child 4267

bd7a7ce2e264

permissions

-rw-r--r--

7066339: Tiered: policy should make consistent decisions about osr levels
Summary: Added feedback disabling flag to common(), fixed handling of TieredStopAtLevel.
Reviewed-by: kvn, never

duke@435	1	/*
iveresov@2138	2	* Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
stefank@2314	25	#ifndef SHARE_VM_INTERPRETER_INVOCATIONCOUNTER_HPP
stefank@2314	26	#define SHARE_VM_INTERPRETER_INVOCATIONCOUNTER_HPP
stefank@2314	27
stefank@2314	28	#include "memory/allocation.hpp"
stefank@2314	29	#include "runtime/handles.hpp"
stefank@2314	30	#include "utilities/exceptions.hpp"
stefank@2314	31
duke@435	32	// InvocationCounters are used to trigger actions when a limit (threshold) is reached.
duke@435	33	// For different states, different limits and actions can be defined in the initialization
duke@435	34	// routine of InvocationCounters.
duke@435	35	//
duke@435	36	// Implementation notes: For space reasons, state & counter are both encoded in one word,
duke@435	37	// The state is encoded using some of the least significant bits, the counter is using the
duke@435	38	// more significant bits. The counter is incremented before a method is activated and an
duke@435	39	// action is triggered when when count() > limit().
duke@435	40
duke@435	41	class InvocationCounter VALUE_OBJ_CLASS_SPEC {
duke@435	42	friend class VMStructs;
duke@435	43	private: // bit no: |31 3| 2 | 1 0 |
duke@435	44	unsigned int _counter; // format: [count|carry|state]
duke@435	45
duke@435	46	enum PrivateConstants {
duke@435	47	number_of_state_bits = 2,
duke@435	48	number_of_carry_bits = 1,
duke@435	49	number_of_noncount_bits = number_of_state_bits + number_of_carry_bits,
duke@435	50	number_of_count_bits = BitsPerInt - number_of_noncount_bits,
duke@435	51	state_limit = nth_bit(number_of_state_bits),
duke@435	52	count_grain = nth_bit(number_of_state_bits + number_of_carry_bits),
duke@435	53	carry_mask = right_n_bits(number_of_carry_bits) << number_of_state_bits,
duke@435	54	state_mask = right_n_bits(number_of_state_bits),
duke@435	55	status_mask = right_n_bits(number_of_state_bits + number_of_carry_bits),
duke@435	56	count_mask = ((int)(-1) ^ status_mask)
duke@435	57	};
duke@435	58
duke@435	59	public:
duke@435	60	static int InterpreterInvocationLimit; // CompileThreshold scaled for interpreter use
duke@435	61	static int InterpreterBackwardBranchLimit; // A separate threshold for on stack replacement
duke@435	62	static int InterpreterProfileLimit; // Profiling threshold scaled for interpreter use
duke@435	63
duke@435	64	typedef address (*Action)(methodHandle method, TRAPS);
duke@435	65
duke@435	66	enum PublicConstants {
duke@435	67	count_increment = count_grain, // use this value to increment the 32bit _counter word
iveresov@2138	68	count_mask_value = count_mask, // use this value to mask the backedge counter
iveresov@2138	69	count_shift = number_of_noncount_bits,
iveresov@2138	70	count_limit = nth_bit(number_of_count_bits - 1)
duke@435	71	};
duke@435	72
duke@435	73	enum State {
duke@435	74	wait_for_nothing, // do nothing when count() > limit()
duke@435	75	wait_for_compile, // introduce nmethod when count() > limit()
duke@435	76	number_of_states // must be <= state_limit
duke@435	77	};
duke@435	78
duke@435	79	// Manipulation
duke@435	80	void reset(); // sets state to wait state
duke@435	81	void init(); // sets state into original state
duke@435	82	void set_state(State state); // sets state and initializes counter correspondingly
duke@435	83	inline void set(State state, int count); // sets state and counter
duke@435	84	inline void decay(); // decay counter (divide by two)
duke@435	85	void set_carry(); // set the sticky carry bit
iveresov@2138	86	void set_carry_flag() { _counter |= carry_mask; }
duke@435	87
duke@435	88	// Accessors
duke@435	89	State state() const { return (State)(_counter & state_mask); }
duke@435	90	bool carry() const { return (_counter & carry_mask) != 0; }
duke@435	91	int limit() const { return CompileThreshold; }
duke@435	92	Action action() const { return _action[state()]; }
duke@435	93	int count() const { return _counter >> number_of_noncount_bits; }
duke@435	94
duke@435	95	int get_InvocationLimit() const { return InterpreterInvocationLimit >> number_of_noncount_bits; }
duke@435	96	int get_BackwardBranchLimit() const { return InterpreterBackwardBranchLimit >> number_of_noncount_bits; }
duke@435	97	int get_ProfileLimit() const { return InterpreterProfileLimit >> number_of_noncount_bits; }
duke@435	98
duke@435	99	// Test counter using scaled limits like the asm interpreter would do rather than doing
duke@435	100	// the shifts to normalize the counter.
duke@435	101
duke@435	102	bool reached_InvocationLimit() const { return _counter >= (unsigned int) InterpreterInvocationLimit; }
duke@435	103	bool reached_BackwardBranchLimit() const { return _counter >= (unsigned int) InterpreterBackwardBranchLimit; }
duke@435	104
duke@435	105	// Do this just like asm interpreter does for max speed
duke@435	106	bool reached_ProfileLimit(InvocationCounter *back_edge_count) const {
duke@435	107	return (_counter && count_mask) + back_edge_count->_counter >= (unsigned int) InterpreterProfileLimit;
duke@435	108	}
duke@435	109
duke@435	110	void increment() { _counter += count_increment; }
duke@435	111
duke@435	112
duke@435	113	// Printing
duke@435	114	void print();
duke@435	115	void print_short();
duke@435	116
duke@435	117	// Miscellaneous
duke@435	118	static ByteSize counter_offset() { return byte_offset_of(InvocationCounter, _counter); }
duke@435	119	static void reinitialize(bool delay_overflow);
duke@435	120
duke@435	121	private:
duke@435	122	static int _init [number_of_states]; // the counter limits
duke@435	123	static Action _action[number_of_states]; // the actions
duke@435	124
duke@435	125	static void def(State state, int init, Action action);
duke@435	126	static const char* state_as_string(State state);
duke@435	127	static const char* state_as_short_string(State state);
duke@435	128	};
duke@435	129
duke@435	130	inline void InvocationCounter::set(State state, int count) {
duke@435	131	assert(0 <= state && state < number_of_states, "illegal state");
duke@435	132	int carry = (_counter & carry_mask); // the carry bit is sticky
duke@435	133	_counter = (count << number_of_noncount_bits) | carry | state;
duke@435	134	}
duke@435	135
duke@435	136	inline void InvocationCounter::decay() {
duke@435	137	int c = count();
duke@435	138	int new_count = c >> 1;
duke@435	139	// prevent from going to zero, to distinguish from never-executed methods
duke@435	140	if (c > 0 && new_count == 0) new_count = 1;
duke@435	141	set(state(), new_count);
duke@435	142	}
iveresov@2138	143
stefank@2314	144
stefank@2314	145	#endif // SHARE_VM_INTERPRETER_INVOCATIONCOUNTER_HPP