/*

 * Copyright (c) 2001, 2010, 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

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 */

class CompileTask;

class CompileQueue;

class SimpleThresholdPolicy : public CompilationPolicy {

  int _c1_count, _c2_count;

  // Check if the counter is big enough and set carry (effectively infinity).

  inline void set_carry_if_necessary(InvocationCounter *counter);

  // Set carry flags in the counters (in methodOop and MDO).

  inline void handle_counter_overflow(methodOop method);

  // Call and loop predicates determine whether a transition to a higher compilation

  // level should be performed (pointers to predicate functions are passed to common_TF().

  // Predicates also take compiler load into account.

  typedef bool (SimpleThresholdPolicy::*Predicate)(int i, int b, CompLevel cur_level);

  bool call_predicate(int i, int b, CompLevel cur_level);

  bool loop_predicate(int i, int b, CompLevel cur_level);

  // Common transition function. Given a predicate determines if a method should transition to another level.

  CompLevel common(Predicate p, methodOop method, CompLevel cur_level);

  // Transition functions.

  // call_event determines if a method should be compiled at a different

  // level with a regular invocation entry.

  CompLevel call_event(methodOop method, CompLevel cur_level);

  // loop_event checks if a method should be OSR compiled at a different

  // level.

  CompLevel loop_event(methodOop method, CompLevel cur_level);

protected:

  int c1_count() const     { return _c1_count; }

  int c2_count() const     { return _c2_count; }

  void set_c1_count(int x) { _c1_count = x;    }

  void set_c2_count(int x) { _c2_count = x;    }

  enum EventType { CALL, LOOP, COMPILE };

  void print_event(EventType type, methodHandle mh, methodHandle imh, int bci, CompLevel level);

  // Print policy-specific information if necessary

  virtual void print_specific(EventType type, methodHandle mh, methodHandle imh, int bci, CompLevel level) { }

  // Check if the method can be compiled, change level if necessary

  void compile(methodHandle mh, int bci, CompLevel level, TRAPS);

  // Submit a given method for compilation

  virtual void submit_compile(methodHandle mh, int bci, CompLevel level, TRAPS);

  // Simple methods are as good being compiled with C1 as C2.

  // This function tells if it's such a function.

  inline bool is_trivial(methodOop method);

  // Predicate helpers are used by .*_predicate() methods as well as others.

  // They check the given counter values, multiplied by the scale against the thresholds.

  template<CompLevel level> static inline bool call_predicate_helper(int i, int b, double scale);

  template<CompLevel level> static inline bool loop_predicate_helper(int i, int b, double scale);

  // Get a compilation level for a given method.

  static CompLevel comp_level(methodOop method) {

    nmethod *nm = method->code();

    if (nm != NULL && nm->is_in_use()) {

      return (CompLevel)nm->comp_level();

    }

    return CompLevel_none;

  }

  virtual void method_invocation_event(methodHandle method, methodHandle inlinee,

                                       CompLevel level, TRAPS);

  virtual void method_back_branch_event(methodHandle method, methodHandle inlinee,

                                        int bci, CompLevel level, TRAPS);

public:

  SimpleThresholdPolicy() : _c1_count(0), _c2_count(0) { }

  virtual int compiler_count(CompLevel comp_level) {

    if (is_c1_compile(comp_level)) return c1_count();

    if (is_c2_compile(comp_level)) return c2_count();

    return 0;

  }

  virtual void do_safepoint_work() { }

  virtual void delay_compilation(methodOop method) { }

  virtual void disable_compilation(methodOop method) { }

  // TODO: we should honour reprofiling requests in the future. Currently reprofiling

  // would happen but not to the extent we would ideally like.

  virtual void reprofile(ScopeDesc* trap_scope, bool is_osr) { }

  virtual nmethod* event(methodHandle method, methodHandle inlinee,

                         int branch_bci, int bci, CompLevel comp_level, TRAPS);

  // Select task is called by CompileBroker. We should return a task or NULL.

  virtual CompileTask* select_task(CompileQueue* compile_queue);

  // Tell the runtime if we think a given method is adequately profiled.

  virtual bool is_mature(methodOop method);

  // Initialize: set compiler thread count

  virtual void initialize();

};