/*

 * Copyright (c) 2015, 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 "gc/shared/collectedHeap.hpp"

#include "gc/shared/collectorPolicy.hpp"

#include "gc/shared/genCollectedHeap.hpp"

#include "gc/shared/threadLocalAllocBuffer.hpp"

#include "runtime/arguments.hpp"

#include "runtime/commandLineFlagConstraintsGC.hpp"

#include "runtime/commandLineFlagRangeList.hpp"

#include "runtime/globals.hpp"

#include "runtime/globals_extension.hpp"

#include "runtime/thread.inline.hpp"

#include "utilities/defaultStream.hpp"

#if INCLUDE_ALL_GCS

#include "gc/cms/concurrentMarkSweepGeneration.inline.hpp"

#include "gc/g1/g1_globals.hpp"

#include "gc/g1/heapRegionBounds.inline.hpp"

#include "gc/shared/plab.hpp"

#endif // INCLUDE_ALL_GCS

#ifdef COMPILER1

#include "c1/c1_globals.hpp"

#endif // COMPILER1

#ifdef COMPILER2

#include "opto/c2_globals.hpp"

#endif // COMPILER2

// Some flags that have default values that indicate that the

// JVM should automatically determine an appropriate value

// for that flag.  In those cases it is only appropriate for the

// constraint checking to be done if the user has specified the

// value(s) of the flag(s) on the command line.  In the constraint

// checking functions,  FLAG_IS_CMDLINE() is used to check if

// the flag has been set by the user and so should be checked.

#if INCLUDE_ALL_GCS

static Flag::Error ParallelGCThreadsAndCMSWorkQueueDrainThreshold(uint threads, uintx threshold, bool verbose) {

  // CMSWorkQueueDrainThreshold is verified to be less than max_juint

  if (UseConcMarkSweepGC && (threads > (uint)(max_jint / (uint)threshold))) {

    CommandLineError::print(verbose,

                            "ParallelGCThreads (" UINT32_FORMAT ") or CMSWorkQueueDrainThreshold ("

                            UINTX_FORMAT ") is too large\n",

                            threads, threshold);

    return Flag::VIOLATES_CONSTRAINT;

  }

  return Flag::SUCCESS;

}

#endif

// As ParallelGCThreads differs among GC modes, we need constraint function.

Flag::Error ParallelGCThreadsConstraintFunc(uint value, bool verbose) {

  Flag::Error status = Flag::SUCCESS;

#if INCLUDE_ALL_GCS

  // Parallel GC passes ParallelGCThreads when creating GrowableArray as 'int' type parameter.

  // So can't exceed with "max_jint"

  if (UseParallelGC && (value > (uint)max_jint)) {

    CommandLineError::print(verbose,

                            "ParallelGCThreads (" UINT32_FORMAT ") must be "

                            "less than or equal to " UINT32_FORMAT " for Parallel GC\n",

                            value, max_jint);

    return Flag::VIOLATES_CONSTRAINT;

  }

  // To avoid overflow at ParScanClosure::do_oop_work.

  if (UseConcMarkSweepGC && (value > (max_jint / 10))) {

    CommandLineError::print(verbose,

                            "ParallelGCThreads (" UINT32_FORMAT ") must be "

                            "less than or equal to " UINT32_FORMAT " for CMS GC\n",

                            value, (max_jint / 10));

    return Flag::VIOLATES_CONSTRAINT;

  }

  status = ParallelGCThreadsAndCMSWorkQueueDrainThreshold(value, CMSWorkQueueDrainThreshold, verbose);

#endif

  return status;

}

// As ConcGCThreads should be smaller than ParallelGCThreads,

// we need constraint function.

Flag::Error ConcGCThreadsConstraintFunc(uint value, bool verbose) {

#if INCLUDE_ALL_GCS

  // CMS and G1 GCs use ConcGCThreads.

  if ((UseConcMarkSweepGC || UseG1GC) && (value > ParallelGCThreads)) {

    CommandLineError::print(verbose,

                            "ConcGCThreads (" UINT32_FORMAT ") must be "

                            "less than or equal to ParallelGCThreads (" UINT32_FORMAT ")\n",

                            value, ParallelGCThreads);

    return Flag::VIOLATES_CONSTRAINT;

  }

#endif

  return Flag::SUCCESS;

}

static Flag::Error MinPLABSizeBounds(const char* name, size_t value, bool verbose) {

#if INCLUDE_ALL_GCS

  if ((UseConcMarkSweepGC || UseG1GC || UseParallelGC) && (value < PLAB::min_size())) {

    CommandLineError::print(verbose,

                            "%s (" SIZE_FORMAT ") must be "

                            "greater than or equal to ergonomic PLAB minimum size (" SIZE_FORMAT ")\n",

                            name, value, PLAB::min_size());

    return Flag::VIOLATES_CONSTRAINT;

  }

#endif // INCLUDE_ALL_GCS

  return Flag::SUCCESS;

}

static Flag::Error MaxPLABSizeBounds(const char* name, size_t value, bool verbose) {

#if INCLUDE_ALL_GCS

  if ((UseConcMarkSweepGC || UseG1GC || UseParallelGC) && (value > PLAB::max_size())) {

    CommandLineError::print(verbose,

                            "%s (" SIZE_FORMAT ") must be "

                            "less than or equal to ergonomic PLAB maximum size (" SIZE_FORMAT ")\n",

                            name, value, PLAB::max_size());

    return Flag::VIOLATES_CONSTRAINT;

  }

#endif // INCLUDE_ALL_GCS

  return Flag::SUCCESS;

}

static Flag::Error MinMaxPLABSizeBounds(const char* name, size_t value, bool verbose) {

  Flag::Error status = MinPLABSizeBounds(name, value, verbose);

  if (status == Flag::SUCCESS) {

    return MaxPLABSizeBounds(name, value, verbose);

  }

  return status;

}

Flag::Error YoungPLABSizeConstraintFunc(size_t value, bool verbose) {

  return MinMaxPLABSizeBounds("YoungPLABSize", value, verbose);

}

Flag::Error OldPLABSizeConstraintFunc(size_t value, bool verbose) {

  Flag::Error status = Flag::SUCCESS;

#if INCLUDE_ALL_GCS

  if (UseConcMarkSweepGC) {

    if (value == 0) {

      CommandLineError::print(verbose,

                              "OldPLABSize (" SIZE_FORMAT ") must be greater than 0",

                              value);

      return Flag::VIOLATES_CONSTRAINT;

    }

    // For CMS, OldPLABSize is the number of free blocks of a given size that are used when

    // replenishing the local per-worker free list caches.

    // For more details, please refer to Arguments::set_cms_and_parnew_gc_flags().

    status = MaxPLABSizeBounds("OldPLABSize", value, verbose);

  } else {

    status = MinMaxPLABSizeBounds("OldPLABSize", value, verbose);

  }

#endif

  return status;

}

Flag::Error MinHeapFreeRatioConstraintFunc(uintx value, bool verbose) {

  if (value > MaxHeapFreeRatio) {

    CommandLineError::print(verbose,

                            "MinHeapFreeRatio (" UINTX_FORMAT ") must be "

                            "less than or equal to MaxHeapFreeRatio (" UINTX_FORMAT ")\n",

                            value, MaxHeapFreeRatio);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

Flag::Error MaxHeapFreeRatioConstraintFunc(uintx value, bool verbose) {

  if (value < MinHeapFreeRatio) {

    CommandLineError::print(verbose,

                            "MaxHeapFreeRatio (" UINTX_FORMAT ") must be "

                            "greater than or equal to MinHeapFreeRatio (" UINTX_FORMAT ")\n",

                            value, MinHeapFreeRatio);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

static Flag::Error CheckMaxHeapSizeAndSoftRefLRUPolicyMSPerMB(size_t maxHeap, intx softRef, bool verbose) {

  if ((softRef > 0) && ((maxHeap / M) > (max_uintx / softRef))) {

    CommandLineError::print(verbose,

                            "Desired lifetime of SoftReferences cannot be expressed correctly. "

                            "MaxHeapSize (" SIZE_FORMAT ") or SoftRefLRUPolicyMSPerMB "

                            "(" INTX_FORMAT ") is too large\n",

                            maxHeap, softRef);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

Flag::Error SoftRefLRUPolicyMSPerMBConstraintFunc(intx value, bool verbose) {

  return CheckMaxHeapSizeAndSoftRefLRUPolicyMSPerMB(MaxHeapSize, value, verbose);

}

Flag::Error MinMetaspaceFreeRatioConstraintFunc(uintx value, bool verbose) {

  if (value > MaxMetaspaceFreeRatio) {

    CommandLineError::print(verbose,

                            "MinMetaspaceFreeRatio (" UINTX_FORMAT ") must be "

                            "less than or equal to MaxMetaspaceFreeRatio (" UINTX_FORMAT ")\n",

                            value, MaxMetaspaceFreeRatio);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

Flag::Error MaxMetaspaceFreeRatioConstraintFunc(uintx value, bool verbose) {

  if (value < MinMetaspaceFreeRatio) {

    CommandLineError::print(verbose,

                            "MaxMetaspaceFreeRatio (" UINTX_FORMAT ") must be "

                            "greater than or equal to MinMetaspaceFreeRatio (" UINTX_FORMAT ")\n",

                            value, MinMetaspaceFreeRatio);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

Flag::Error InitialTenuringThresholdConstraintFunc(uintx value, bool verbose) {

#if INCLUDE_ALL_GCS

  // InitialTenuringThreshold is only used for ParallelGC.

  if (UseParallelGC && (value > MaxTenuringThreshold)) {

      CommandLineError::print(verbose,

                              "InitialTenuringThreshold (" UINTX_FORMAT ") must be "

                              "less than or equal to MaxTenuringThreshold (" UINTX_FORMAT ")\n",

                              value, MaxTenuringThreshold);

      return Flag::VIOLATES_CONSTRAINT;

  }

#endif

  return Flag::SUCCESS;

}

Flag::Error MaxTenuringThresholdConstraintFunc(uintx value, bool verbose) {

#if INCLUDE_ALL_GCS

  // As only ParallelGC uses InitialTenuringThreshold,

  // we don't need to compare InitialTenuringThreshold with MaxTenuringThreshold.

  if (UseParallelGC && (value < InitialTenuringThreshold)) {

    CommandLineError::print(verbose,

                            "MaxTenuringThreshold (" UINTX_FORMAT ") must be "

                            "greater than or equal to InitialTenuringThreshold (" UINTX_FORMAT ")\n",

                            value, InitialTenuringThreshold);

    return Flag::VIOLATES_CONSTRAINT;

  }

#endif

  // MaxTenuringThreshold=0 means NeverTenure=false && AlwaysTenure=true

  if ((value == 0) && (NeverTenure || !AlwaysTenure)) {

    CommandLineError::print(verbose,

                            "MaxTenuringThreshold (0) should match to NeverTenure=false "

                            "&& AlwaysTenure=true. But we have NeverTenure=%s "

                            "AlwaysTenure=%s\n",

                            NeverTenure ? "true" : "false",

                            AlwaysTenure ? "true" : "false");

    return Flag::VIOLATES_CONSTRAINT;

  }

  return Flag::SUCCESS;

}

#if INCLUDE_ALL_GCS

Flag::Error G1RSetRegionEntriesConstraintFunc(intx value, bool verbose) {

  if (!UseG1GC) return Flag::SUCCESS;

  // Default value of G1RSetRegionEntries=0 means will be set ergonomically.

  // Minimum value is 1.

  if (FLAG_IS_CMDLINE(G1RSetRegionEntries) && (value < 1)) {

    CommandLineError::print(verbose,

                            "G1RSetRegionEntries (" INTX_FORMAT ") must be "

                            "greater than or equal to 1\n",

                            value);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

Flag::Error G1RSetSparseRegionEntriesConstraintFunc(intx value, bool verbose) {

  if (!UseG1GC) return Flag::SUCCESS;

  // Default value of G1RSetSparseRegionEntries=0 means will be set ergonomically.

  // Minimum value is 1.

  if (FLAG_IS_CMDLINE(G1RSetSparseRegionEntries) && (value < 1)) {

    CommandLineError::print(verbose,

                            "G1RSetSparseRegionEntries (" INTX_FORMAT ") must be "

                            "greater than or equal to 1\n",

                            value);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

Flag::Error G1HeapRegionSizeConstraintFunc(size_t value, bool verbose) {

  if (!UseG1GC) return Flag::SUCCESS;

  // Default value of G1HeapRegionSize=0 means will be set ergonomically.

  if (FLAG_IS_CMDLINE(G1HeapRegionSize) && (value < HeapRegionBounds::min_size())) {

    CommandLineError::print(verbose,

                            "G1HeapRegionSize (" SIZE_FORMAT ") must be "

                            "greater than or equal to ergonomic heap region minimum size\n",

                            value);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

Flag::Error G1NewSizePercentConstraintFunc(uintx value, bool verbose) {

  if (!UseG1GC) return Flag::SUCCESS;

  if (value > G1MaxNewSizePercent) {

    CommandLineError::print(verbose,

                            "G1NewSizePercent (" UINTX_FORMAT ") must be "

                            "less than or equal to G1MaxNewSizePercent (" UINTX_FORMAT ")\n",

                            value, G1MaxNewSizePercent);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

Flag::Error G1MaxNewSizePercentConstraintFunc(uintx value, bool verbose) {

  if (!UseG1GC) return Flag::SUCCESS;

  if (value < G1NewSizePercent) {

    CommandLineError::print(verbose,

                            "G1MaxNewSizePercent (" UINTX_FORMAT ") must be "

                            "greater than or equal to G1NewSizePercent (" UINTX_FORMAT ")\n",

                            value, G1NewSizePercent);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

#endif // INCLUDE_ALL_GCS

Flag::Error ParGCStridesPerThreadConstraintFunc(uintx value, bool verbose) {

#if INCLUDE_ALL_GCS

  if (UseConcMarkSweepGC && (value > ((uintx)max_jint / (uintx)ParallelGCThreads))) {

    CommandLineError::print(verbose,

                            "ParGCStridesPerThread (" UINTX_FORMAT ") must be "

                            "less than or equal to ergonomic maximum (" UINTX_FORMAT ")\n",

                            value, ((uintx)max_jint / (uintx)ParallelGCThreads));

    return Flag::VIOLATES_CONSTRAINT;

  }

#endif

  return Flag::SUCCESS;

}

Flag::Error ParGCCardsPerStrideChunkConstraintFunc(intx value, bool verbose) {

#if INCLUDE_ALL_GCS

  if (UseConcMarkSweepGC) {

    // ParGCCardsPerStrideChunk should be compared with card table size.

    size_t heap_size = Universe::heap()->reserved_region().word_size();

    CardTableModRefBS* bs = (CardTableModRefBS*)GenCollectedHeap::heap()->rem_set()->bs();

    size_t card_table_size = bs->cards_required(heap_size) - 1; // Valid card table size

    if ((size_t)value > card_table_size) {

      CommandLineError::print(verbose,

                              "ParGCCardsPerStrideChunk (" INTX_FORMAT ") is too large for the heap size and "

                              "must be less than or equal to card table size (" SIZE_FORMAT ")\n",

                              value, card_table_size);

      return Flag::VIOLATES_CONSTRAINT;

    }

    // ParGCCardsPerStrideChunk is used with n_strides(ParallelGCThreads*ParGCStridesPerThread)

    // from CardTableModRefBSForCTRS::process_stride(). Note that ParGCStridesPerThread is already checked

    // not to make an overflow with ParallelGCThreads from its constraint function.

    uintx n_strides = ParallelGCThreads * ParGCStridesPerThread;

    uintx ergo_max = max_uintx / n_strides;

    if ((uintx)value > ergo_max) {

      CommandLineError::print(verbose,

                              "ParGCCardsPerStrideChunk (" INTX_FORMAT ") must be "

                              "less than or equal to ergonomic maximum (" UINTX_FORMAT ")\n",

                              value, ergo_max);

      return Flag::VIOLATES_CONSTRAINT;

    }

  }

#endif

  return Flag::SUCCESS;

}

Flag::Error CMSOldPLABMinConstraintFunc(size_t value, bool verbose) {

  Flag::Error status = Flag::SUCCESS;

#if INCLUDE_ALL_GCS

  if (UseConcMarkSweepGC) {

    if (value > CMSOldPLABMax) {

      CommandLineError::print(verbose,

                              "CMSOldPLABMin (" SIZE_FORMAT ") must be "

                              "less than or equal to CMSOldPLABMax (" SIZE_FORMAT ")\n",

                              value, CMSOldPLABMax);

      return Flag::VIOLATES_CONSTRAINT;

    }

    status = MaxPLABSizeBounds("CMSOldPLABMin", value, verbose);

  }

#endif

  return status;

}

Flag::Error CMSOldPLABMaxConstraintFunc(size_t value, bool verbose) {

  Flag::Error status = Flag::SUCCESS;

#if INCLUDE_ALL_GCS

  if (UseConcMarkSweepGC) {

    status = MaxPLABSizeBounds("CMSOldPLABMax", value, verbose);

  }

#endif

  return status;

}

Flag::Error MarkStackSizeConstraintFunc(size_t value, bool verbose) {

  if (value > MarkStackSizeMax) {

    CommandLineError::print(verbose,

                            "MarkStackSize (" SIZE_FORMAT ") must be "

                            "less than or equal to MarkStackSizeMax (" SIZE_FORMAT ")\n",

                            value, MarkStackSizeMax);

    return Flag::VIOLATES_CONSTRAINT;

  } else {

    return Flag::SUCCESS;

  }

}

static Flag::Error CMSReservedAreaConstraintFunc(const char* name, size_t value, bool verbose) {

#if INCLUDE_ALL_GCS

  if (UseConcMarkSweepGC) {

    ConcurrentMarkSweepGeneration* cms = (ConcurrentMarkSweepGeneration*)GenCollectedHeap::heap()->old_gen();

    const size_t ergo_max = cms->cmsSpace()->max_flag_size_for_task_size();

    if (value > ergo_max) {

      CommandLineError::print(verbose,

                              "%s (" SIZE_FORMAT ") must be "

                              "less than or equal to ergonomic maximum (" SIZE_FORMAT ") "

                              "which is based on the maximum size of the old generation of the Java heap\n",

                              name, value, ergo_max);

      return Flag::VIOLATES_CONSTRAINT;

    }

  }

#endif

  return Flag::SUCCESS;

}

Flag::Error CMSRescanMultipleConstraintFunc(size_t value, bool verbose) {

  Flag::Error status = CMSReservedAreaConstraintFunc("CMSRescanMultiple", value, verbose);

#if INCLUDE_ALL_GCS

  if (status == Flag::SUCCESS && UseConcMarkSweepGC) {

    // CMSParRemarkTask::do_dirty_card_rescan_tasks requires CompactibleFreeListSpace::rescan_task_size()

    // to be aligned to CardTableModRefBS::card_size * BitsPerWord.

    // Note that rescan_task_size() will be aligned if CMSRescanMultiple is a multiple of 'HeapWordSize'

    // because rescan_task_size() is CardTableModRefBS::card_size / HeapWordSize * BitsPerWord.

    if (value % HeapWordSize != 0) {

      CommandLineError::print(verbose,

                              "CMSRescanMultiple (" SIZE_FORMAT ") must be "

                              "a multiple of " SIZE_FORMAT "\n",

                              value, HeapWordSize);

      status = Flag::VIOLATES_CONSTRAINT;

    }

  }

#endif

  return status;

}

Flag::Error CMSConcMarkMultipleConstraintFunc(size_t value, bool verbose) {

  return CMSReservedAreaConstraintFunc("CMSConcMarkMultiple", value, verbose);

}

Flag::Error CMSPrecleanDenominatorConstraintFunc(uintx value, bool verbose) {

#if INCLUDE_ALL_GCS

  if (UseConcMarkSweepGC && (value <= CMSPrecleanNumerator)) {

    CommandLineError::print(verbose,

                            "CMSPrecleanDenominator (" UINTX_FORMAT ") must be "

                            "strickly greater than CMSPrecleanNumerator (" UINTX_FORMAT ")\n",