--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/interpreter/invocationCounter.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,157 @@
+/*
+ * 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