/*

 * Copyright (c) 2010, 2016, 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.

 *

 */

#include "precompiled.hpp"

#include "compiler/compileBroker.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/arguments.hpp"

#include "runtime/simpleThresholdPolicy.hpp"

#include "runtime/simpleThresholdPolicy.inline.hpp"

#include "code/scopeDesc.hpp"

void SimpleThresholdPolicy::print_counters(const char* prefix, methodHandle mh) {

  int invocation_count = mh->invocation_count();

  int backedge_count = mh->backedge_count();

  MethodData* mdh = mh->method_data();

  int mdo_invocations = 0, mdo_backedges = 0;

  int mdo_invocations_start = 0, mdo_backedges_start = 0;

  if (mdh != NULL) {

    mdo_invocations = mdh->invocation_count();

    mdo_backedges = mdh->backedge_count();

    mdo_invocations_start = mdh->invocation_count_start();

    mdo_backedges_start = mdh->backedge_count_start();

  }

  tty->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,

      invocation_count, backedge_count, prefix,

      mdo_invocations, mdo_invocations_start,

      mdo_backedges, mdo_backedges_start);

  tty->print(" %smax levels=%d,%d", prefix,

      mh->highest_comp_level(), mh->highest_osr_comp_level());

}

// Print an event.

void SimpleThresholdPolicy::print_event(EventType type, methodHandle mh, methodHandle imh,

                                        int bci, CompLevel level) {

  bool inlinee_event = mh() != imh();

  ttyLocker tty_lock;

  tty->print("%lf: [", os::elapsedTime());

  switch(type) {

  case CALL:

    tty->print("call");

    break;

  case LOOP:

    tty->print("loop");

    break;

  case COMPILE:

    tty->print("compile");

    break;

  case REMOVE_FROM_QUEUE:

    tty->print("remove-from-queue");

    break;

  case UPDATE_IN_QUEUE:

    tty->print("update-in-queue");

    break;

  case REPROFILE:

    tty->print("reprofile");

    break;

  case MAKE_NOT_ENTRANT:

    tty->print("make-not-entrant");

    break;

  default:

    tty->print("unknown");

  }

  tty->print(" level=%d ", level);

  ResourceMark rm;

  char *method_name = mh->name_and_sig_as_C_string();

  tty->print("[%s", method_name);

  if (inlinee_event) {

    char *inlinee_name = imh->name_and_sig_as_C_string();

    tty->print(" [%s]] ", inlinee_name);

  }

  else tty->print("] ");

  tty->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),

                                      CompileBroker::queue_size(CompLevel_full_optimization));

  print_specific(type, mh, imh, bci, level);

  if (type != COMPILE) {

    print_counters("", mh);

    if (inlinee_event) {

      print_counters("inlinee ", imh);

    }

    tty->print(" compilable=");

    bool need_comma = false;

    if (!mh->is_not_compilable(CompLevel_full_profile)) {

      tty->print("c1");

      need_comma = true;

    }

    if (!mh->is_not_osr_compilable(CompLevel_full_profile)) {

      if (need_comma) tty->print(",");

      tty->print("c1-osr");

      need_comma = true;

    }

    if (!mh->is_not_compilable(CompLevel_full_optimization)) {

      if (need_comma) tty->print(",");

      tty->print("c2");

      need_comma = true;

    }

    if (!mh->is_not_osr_compilable(CompLevel_full_optimization)) {

      if (need_comma) tty->print(",");

      tty->print("c2-osr");

    }

    tty->print(" status=");

    if (mh->queued_for_compilation()) {

      tty->print("in-queue");

    } else tty->print("idle");

  }

  tty->print_cr("]");

}

void SimpleThresholdPolicy::initialize() {

  if (FLAG_IS_DEFAULT(CICompilerCount)) {

    FLAG_SET_DEFAULT(CICompilerCount, 3);

  }

  int count = CICompilerCount;

#ifdef _LP64

  // On 64-bit systems, scale the number of compiler threads with

  // the number of cores available on the system. Scaling is not

  // performed on 32-bit systems because it can lead to exhaustion

  // of the virtual memory address space available to the JVM.

  if (CICompilerCountPerCPU) {

    count = MAX2(log2_intptr(os::active_processor_count()), 1) * 3 / 2;

  }

#endif

  set_c1_count(MAX2(count / 3, 1));

  set_c2_count(MAX2(count - c1_count(), 1));

  FLAG_SET_ERGO(intx, CICompilerCount, c1_count() + c2_count());

}

void SimpleThresholdPolicy::set_carry_if_necessary(InvocationCounter *counter) {

  if (!counter->carry() && counter->count() > InvocationCounter::count_limit / 2) {

    counter->set_carry_flag();

  }

}

// Set carry flags on the counters if necessary

void SimpleThresholdPolicy::handle_counter_overflow(Method* method) {

  MethodCounters *mcs = method->method_counters();

  if (mcs != NULL) {

    set_carry_if_necessary(mcs->invocation_counter());

    set_carry_if_necessary(mcs->backedge_counter());

  }

  MethodData* mdo = method->method_data();

  if (mdo != NULL) {

    set_carry_if_necessary(mdo->invocation_counter());

    set_carry_if_necessary(mdo->backedge_counter());

  }

}

// Called with the queue locked and with at least one element

CompileTask* SimpleThresholdPolicy::select_task(CompileQueue* compile_queue) {

  return select_task_helper(compile_queue);

}

void SimpleThresholdPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {

  for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {

    if (PrintTieredEvents) {

      methodHandle mh(sd->method());

      print_event(REPROFILE, mh, mh, InvocationEntryBci, CompLevel_none);

    }

    MethodData* mdo = sd->method()->method_data();

    if (mdo != NULL) {

      mdo->reset_start_counters();

    }

    if (sd->is_top()) break;

  }

}

nmethod* SimpleThresholdPolicy::event(const methodHandle& method, const methodHandle& inlinee,

                                      int branch_bci, int bci, CompLevel comp_level, CompiledMethod* nm, JavaThread* thread) {

  if (comp_level == CompLevel_none &&

      JvmtiExport::can_post_interpreter_events() &&

      thread->is_interp_only_mode()) {

    return NULL;

  }

  if (CompileTheWorld || ReplayCompiles) {

    // Don't trigger other compiles in testing mode

    return NULL;

  }

  handle_counter_overflow(method());

  if (method() != inlinee()) {

    handle_counter_overflow(inlinee());

  }

  if (PrintTieredEvents) {

    print_event(bci == InvocationEntryBci ? CALL : LOOP, method, inlinee, bci, comp_level);

  }

  if (bci == InvocationEntryBci) {

    method_invocation_event(method, inlinee, comp_level, nm, thread);

  } else {

    // method == inlinee if the event originated in the main method

    method_back_branch_event(method, inlinee, bci, comp_level, nm, thread);

    // Check if event led to a higher level OSR compilation

    nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, comp_level, false);

    if (osr_nm != NULL && osr_nm->comp_level() > comp_level) {

      // Perform OSR with new nmethod

      return osr_nm;

    }

  }

  return NULL;

}

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

void SimpleThresholdPolicy::compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread) {

  assert(level <= TieredStopAtLevel, "Invalid compilation level");

  if (level == CompLevel_none) {

    return;

  }

#if INCLUDE_JVMCI

  // We can't compile with a JVMCI compiler until the module system is initialized.

  if (level == CompLevel_full_optimization && UseJVMCICompiler && !Universe::is_module_initialized()) {

    return;

  }

#endif

  // Check if the method can be compiled. If it cannot be compiled with C1, continue profiling

  // in the interpreter and then compile with C2 (the transition function will request that,

  // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with

  // pure C1.

  if (!can_be_compiled(mh, level)) {

    if (level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {

        compile(mh, bci, CompLevel_simple, thread);

    }

    return;

  }

  if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {

    return;

  }

  if (!CompileBroker::compilation_is_in_queue(mh)) {

    if (PrintTieredEvents) {

      print_event(COMPILE, mh, mh, bci, level);

    }

    submit_compile(mh, bci, level, thread);

  }

}

// Tell the broker to compile the method

void SimpleThresholdPolicy::submit_compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread) {

  int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();

  CompileBroker::compile_method(mh, bci, level, mh, hot_count, CompileTask::Reason_Tiered, thread);

}

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

// compilation level should be performed (pointers to predicate functions

// are passed to common() transition function).

bool SimpleThresholdPolicy::loop_predicate(int i, int b, CompLevel cur_level, Method* method) {

  switch(cur_level) {

  case CompLevel_none:

  case CompLevel_limited_profile: {

    return loop_predicate_helper<CompLevel_none>(i, b, 1.0, method);

  }

  case CompLevel_full_profile: {

    return loop_predicate_helper<CompLevel_full_profile>(i, b, 1.0, method);

  }

  default:

    return true;

  }

}

bool SimpleThresholdPolicy::call_predicate(int i, int b, CompLevel cur_level, Method* method) {

  switch(cur_level) {

  case CompLevel_none:

  case CompLevel_limited_profile: {

    return call_predicate_helper<CompLevel_none>(i, b, 1.0, method);

  }

  case CompLevel_full_profile: {

    return call_predicate_helper<CompLevel_full_profile>(i, b, 1.0, method);

  }

  default:

    return true;

  }

}

// Determine is a method is mature.

bool SimpleThresholdPolicy::is_mature(Method* method) {

  if (is_trivial(method)) return true;

  MethodData* mdo = method->method_data();

  if (mdo != NULL) {

    int i = mdo->invocation_count();

    int b = mdo->backedge_count();

    double k = ProfileMaturityPercentage / 100.0;

    return call_predicate_helper<CompLevel_full_profile>(i, b, k, method) ||

           loop_predicate_helper<CompLevel_full_profile>(i, b, k, method);

  }

  return false;

}

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

CompLevel SimpleThresholdPolicy::common(Predicate p, Method* method, CompLevel cur_level) {

  CompLevel next_level = cur_level;

  int i = method->invocation_count();

  int b = method->backedge_count();

  if (is_trivial(method)) {

    next_level = CompLevel_simple;

  } else {

    switch(cur_level) {

    case CompLevel_none:

      // If we were at full profile level, would we switch to full opt?

      if (common(p, method, CompLevel_full_profile) == CompLevel_full_optimization) {

        next_level = CompLevel_full_optimization;

      } else if ((this->*p)(i, b, cur_level, method)) {

        next_level = CompLevel_full_profile;

      }

      break;

    case CompLevel_limited_profile:

    case CompLevel_full_profile:

      {

        MethodData* mdo = method->method_data();

        if (mdo != NULL) {

          if (mdo->would_profile()) {

            int mdo_i = mdo->invocation_count_delta();

            int mdo_b = mdo->backedge_count_delta();

            if ((this->*p)(mdo_i, mdo_b, cur_level, method)) {

              next_level = CompLevel_full_optimization;

            }

          } else {

            next_level = CompLevel_full_optimization;

          }

        }

      }

      break;

    }

  }

  return MIN2(next_level, (CompLevel)TieredStopAtLevel);

}

// Determine if a method should be compiled with a normal entry point at a different level.

  CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(),

                             common(&SimpleThresholdPolicy::loop_predicate, method, cur_level));

  CompLevel next_level = common(&SimpleThresholdPolicy::call_predicate, method, cur_level);

  // If OSR method level is greater than the regular method level, the levels should be

  // equalized by raising the regular method level in order to avoid OSRs during each

  // invocation of the method.

  if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {

    MethodData* mdo = method->method_data();

    guarantee(mdo != NULL, "MDO should not be NULL");

    if (mdo->invocation_count() >= 1) {

      next_level = CompLevel_full_optimization;

    }

  } else {

    next_level = MAX2(osr_level, next_level);

  }

  return next_level;

}

// Determine if we should do an OSR compilation of a given method.

  CompLevel next_level = common(&SimpleThresholdPolicy::loop_predicate, method, cur_level);

  if (cur_level == CompLevel_none) {

    // If there is a live OSR method that means that we deopted to the interpreter

    // for the transition.

    CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);

    if (osr_level > CompLevel_none) {

      return osr_level;

    }

  }

  return next_level;

}

// Handle the invocation event.

void SimpleThresholdPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,

                                              CompLevel level, CompiledMethod* nm, JavaThread* thread) {

  if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {

    if (next_level != level) {

      compile(mh, InvocationEntryBci, next_level, thread);

    }

  }

}

// Handle the back branch event. Notice that we can compile the method

// with a regular entry from here.

void SimpleThresholdPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,

                                                     int bci, CompLevel level, CompiledMethod* nm, JavaThread* thread) {

  // If the method is already compiling, quickly bail out.

  if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {

    // Use loop event as an opportunity to also check there's been

    // enough calls.

    CompLevel cur_level = comp_level(mh());

    next_level = MAX2(next_level,

                      next_osr_level < CompLevel_full_optimization ? next_osr_level : cur_level);

    bool is_compiling = false;

    if (next_level != cur_level) {

      compile(mh, InvocationEntryBci, next_level, thread);

      is_compiling = true;

    }

    // Do the OSR version

    if (!is_compiling && next_osr_level != level) {

      compile(mh, bci, next_osr_level, thread);

    }

  }

}