/*

 * Copyright (c) 2000, 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

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 */

#ifndef SHARE_VM_RUNTIME_COMPILATIONPOLICY_HPP

#define SHARE_VM_RUNTIME_COMPILATIONPOLICY_HPP

#include "code/nmethod.hpp"

#include "compiler/compileBroker.hpp"

#include "memory/allocation.hpp"

#include "runtime/vm_operations.hpp"

#include "utilities/growableArray.hpp"

// The CompilationPolicy selects which method (if any) should be compiled.

// It also decides which methods must always be compiled (i.e., are never

// interpreted).

class CompileTask;

class CompileQueue;

class CompilationPolicy : public CHeapObj {

  static CompilationPolicy* _policy;

  // Accumulated time

  static elapsedTimer       _accumulated_time;

  static bool               _in_vm_startup;

public:

  static  void set_in_vm_startup(bool in_vm_startup) { _in_vm_startup = in_vm_startup; }

  static  void completed_vm_startup();

  static  bool delay_compilation_during_startup()    { return _in_vm_startup; }

  // m must be compiled before executing it

  static bool must_be_compiled(methodHandle m, int comp_level = CompLevel_all);

  // m is allowed to be compiled

  static bool can_be_compiled(methodHandle m, int comp_level = CompLevel_all);

  static bool is_compilation_enabled();

  static void set_policy(CompilationPolicy* policy) { _policy = policy; }

  static CompilationPolicy* policy()                { return _policy; }

  // Profiling

  elapsedTimer* accumulated_time() { return &_accumulated_time; }

  void print_time() PRODUCT_RETURN;

  virtual int compiler_count(CompLevel comp_level) = 0;

  // main notification entry, return a pointer to an nmethod if the OSR is required,

  // returns NULL otherwise.

  // safepoint() is called at the end of the safepoint

  virtual void do_safepoint_work() = 0;

  // reprofile request

  virtual void reprofile(ScopeDesc* trap_scope, bool is_osr) = 0;

  // delay_compilation(method) can be called by any component of the runtime to notify the policy

  // that it's recommended to delay the complation of this method.

  virtual void delay_compilation(methodOop method) = 0;

  // disable_compilation() is called whenever the runtime decides to disable compilation of the

  // specified method.

  virtual void disable_compilation(methodOop method) = 0;

  // Select task is called by CompileBroker. The queue is guaranteed to have at least one

  // element and is locked. The function should select one and return it.

  virtual CompileTask* select_task(CompileQueue* compile_queue) = 0;

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

  virtual bool is_mature(methodOop method) = 0;

  // Do policy initialization

  virtual void initialize() = 0;

};

// A base class for baseline policies.

class NonTieredCompPolicy : public CompilationPolicy {

  int _compiler_count;

protected:

  static void trace_frequency_counter_overflow(methodHandle m, int branch_bci, int bci);

  static void trace_osr_request(methodHandle method, nmethod* osr, int bci);

  static void trace_osr_completion(nmethod* osr_nm);

  void reset_counter_for_invocation_event(methodHandle method);

  void reset_counter_for_back_branch_event(methodHandle method);

public:

  NonTieredCompPolicy() : _compiler_count(0) { }

  virtual int compiler_count(CompLevel comp_level);

  virtual void do_safepoint_work();

  virtual void reprofile(ScopeDesc* trap_scope, bool is_osr);

  virtual void delay_compilation(methodOop method);

  virtual void disable_compilation(methodOop method);

  virtual bool is_mature(methodOop method);

  virtual void initialize();

  virtual CompileTask* select_task(CompileQueue* compile_queue);

  virtual void method_invocation_event(methodHandle m, TRAPS) = 0;

  virtual void method_back_branch_event(methodHandle m, int bci, TRAPS) = 0;

};

class SimpleCompPolicy : public NonTieredCompPolicy {

 public:

  virtual void method_invocation_event(methodHandle m, TRAPS);

  virtual void method_back_branch_event(methodHandle m, int bci, TRAPS);

};

// StackWalkCompPolicy - existing C2 policy

#ifdef COMPILER2

class StackWalkCompPolicy : public NonTieredCompPolicy {

 public:

  virtual void method_invocation_event(methodHandle m, TRAPS);

  virtual void method_back_branch_event(methodHandle m, int bci, TRAPS);

 private:

  RFrame* findTopInlinableFrame(GrowableArray<RFrame*>* stack);

  RFrame* senderOf(RFrame* rf, GrowableArray<RFrame*>* stack);

  // the following variables hold values computed by the last inlining decision

  // they are used for performance debugging only (print better messages)

  static const char* _msg;            // reason for not inlining

  static const char* shouldInline   (methodHandle callee, float frequency, int cnt);

  // positive filter: should send be inlined?  returns NULL (--> yes) or rejection msg

  static const char* shouldNotInline(methodHandle callee);

  // negative filter: should send NOT be inlined?  returns NULL (--> inline) or rejection msg

};

#endif

#endif // SHARE_VM_RUNTIME_COMPILATIONPOLICY_HPP