Java example source code file (simpleThresholdPolicy.cpp)

This example Java source code file (simpleThresholdPolicy.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

compilebroker\:\:compilation_is_in_queue, complevel, complevel_full_optimization, complevel_full_profile, complevel_limited_profile, complevel_none, complevel_simple, invocationentrybci, javathread, max2, methoddata, min2, null, simplethresholdpolicy\:\:loop_predicate

The simpleThresholdPolicy.cpp Java example source code

/*
 * Copyright (c) 2010, 2013, 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;
  if (CICompilerCountPerCPU) {
    count = MAX2(log2_intptr(os::active_processor_count()), 1) * 3 / 2;
  }
  set_c1_count(MAX2(count / 3, 1));
  set_c2_count(MAX2(count - count / 3, 1));
}

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 compile_queue->first();
}

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(methodHandle method, methodHandle inlinee,
                                      int branch_bci, int bci, CompLevel comp_level, nmethod* nm, JavaThread* thread) {
  if (comp_level == CompLevel_none &&
      JvmtiExport::can_post_interpreter_events() &&
      thread->is_interp_only_mode()) {
    return NULL;
  }
  nmethod *osr_nm = 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_back_branch_event(method, inlinee, bci, comp_level, nm, thread);
    // method == inlinee if the event originated in the main method
    int highest_level = inlinee->highest_osr_comp_level();
    if (highest_level > comp_level) {
      osr_nm = inlinee->lookup_osr_nmethod_for(bci, highest_level, false);
    }
  }
  return osr_nm;
}

// Check if the method can be compiled, change level if necessary
void SimpleThresholdPolicy::compile(methodHandle mh, int bci, CompLevel level, JavaThread* thread) {
  assert(level <= TieredStopAtLevel, "Invalid compilation level");
  if (level == CompLevel_none) {
    return;
  }
  // 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, bci)) {
    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(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, "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) {
  switch(cur_level) {
  case CompLevel_none:
  case CompLevel_limited_profile: {
    return loop_predicate_helper<CompLevel_none>(i, b, 1.0);
  }
  case CompLevel_full_profile: {
    return loop_predicate_helper<CompLevel_full_profile>(i, b, 1.0);
  }
  default:
    return true;
  }
}

bool SimpleThresholdPolicy::call_predicate(int i, int b, CompLevel cur_level) {
  switch(cur_level) {
  case CompLevel_none:
  case CompLevel_limited_profile: {
    return call_predicate_helper<CompLevel_none>(i, b, 1.0);
  }
  case CompLevel_full_profile: {
    return call_predicate_helper<CompLevel_full_profile>(i, b, 1.0);
  }
  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) ||
           loop_predicate_helper<CompLevel_full_profile>(i, b, k);
  }
  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)) {
        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)) {
              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 SimpleThresholdPolicy::call_event(Method* method,  CompLevel cur_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 SimpleThresholdPolicy::loop_event(Method* method, CompLevel cur_level) {
  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(methodHandle mh, methodHandle imh,
                                              CompLevel level, nmethod* nm, JavaThread* thread) {
  if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh, InvocationEntryBci)) {
    CompLevel next_level = call_event(mh(), level);
    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(methodHandle mh, methodHandle imh,
                                                     int bci, CompLevel level, nmethod* nm, JavaThread* thread) {
  // If the method is already compiling, quickly bail out.
  if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh, bci)) {
    // Use loop event as an opportinity to also check there's been
    // enough calls.
    CompLevel cur_level = comp_level(mh());
    CompLevel next_level = call_event(mh(), cur_level);
    CompLevel next_osr_level = loop_event(mh(), level);

    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);
    }
  }
}