/*

 * Copyright (c) 2015, 2018, 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/gcConfig.hpp"

#include "gc/shared/jvmFlagConstraintsGC.hpp"

#include "gc/shared/plab.hpp"

#include "gc/shared/threadLocalAllocBuffer.hpp"

#include "runtime/arguments.hpp"

#include "runtime/globals.hpp"

#include "runtime/globals_extension.hpp"

#include "runtime/thread.inline.hpp"

#include "utilities/align.hpp"

#include "utilities/macros.hpp"

#if INCLUDE_CMSGC

#include "gc/cms/jvmFlagConstraintsCMS.hpp"

#endif

#if INCLUDE_G1GC

#include "gc/g1/jvmFlagConstraintsG1.hpp"

#endif

#if INCLUDE_PARALLELGC

#include "gc/parallel/jvmFlagConstraintsParallel.hpp"

#endif

#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.

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

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

  JVMFlag::Error status = JVMFlag::SUCCESS;

#if INCLUDE_PARALLELGC

  status = ParallelGCThreadsConstraintFuncParallel(value, verbose);

  if (status != JVMFlag::SUCCESS) {

    return status;

  }

#endif

#if INCLUDE_CMSGC

  status = ParallelGCThreadsConstraintFuncCMS(value, verbose);

  if (status != JVMFlag::SUCCESS) {

    return status;

  }

#endif

  return status;

}

// As ConcGCThreads should be smaller than ParallelGCThreads,

// we need constraint function.

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

  // CMS and G1 GCs use ConcGCThreads.

  if ((GCConfig::is_gc_selected(CollectedHeap::CMS) ||

       GCConfig::is_gc_selected(CollectedHeap::G1)) && (value > ParallelGCThreads)) {

    JVMFlag::printError(verbose,

                        "ConcGCThreads (" UINT32_FORMAT ") must be "

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

                        value, ParallelGCThreads);

    return JVMFlag::VIOLATES_CONSTRAINT;

  }

  return JVMFlag::SUCCESS;

}

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

  if ((GCConfig::is_gc_selected(CollectedHeap::CMS) ||

       GCConfig::is_gc_selected(CollectedHeap::G1)  ||

       GCConfig::is_gc_selected(CollectedHeap::Parallel)) && (value < PLAB::min_size())) {

    JVMFlag::printError(verbose,

                        "%s (" SIZE_FORMAT ") must be "

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

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

    return JVMFlag::VIOLATES_CONSTRAINT;

  }

  return JVMFlag::SUCCESS;

}

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

  if ((GCConfig::is_gc_selected(CollectedHeap::CMS) ||

       GCConfig::is_gc_selected(CollectedHeap::G1)  ||

       GCConfig::is_gc_selected(CollectedHeap::Parallel)) && (value > PLAB::max_size())) {

    JVMFlag::printError(verbose,

                        "%s (" SIZE_FORMAT ") must be "

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

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

    return JVMFlag::VIOLATES_CONSTRAINT;

  }

  return JVMFlag::SUCCESS;

}

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

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

  if (status == JVMFlag::SUCCESS) {

    return MaxPLABSizeBounds(name, value, verbose);

  }

  return status;

}

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

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

}

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

  JVMFlag::Error status = JVMFlag::SUCCESS;

#if INCLUDE_CMSGC

  if (UseConcMarkSweepGC) {

    return OldPLABSizeConstraintFuncCMS(value, verbose);

  } else

#endif

  {

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

  }

  return status;

}

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

  if (value > MaxHeapFreeRatio) {

    JVMFlag::printError(verbose,

                        "MinHeapFreeRatio (" UINTX_FORMAT ") must be "

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

                        value, MaxHeapFreeRatio);

    return JVMFlag::VIOLATES_CONSTRAINT;

  } else {

    return JVMFlag::SUCCESS;

  }

}

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

  if (value < MinHeapFreeRatio) {

    JVMFlag::printError(verbose,

                        "MaxHeapFreeRatio (" UINTX_FORMAT ") must be "

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

                        value, MinHeapFreeRatio);

    return JVMFlag::VIOLATES_CONSTRAINT;

  } else {

    return JVMFlag::SUCCESS;

  }

}

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

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

    JVMFlag::printError(verbose,

                        "Desired lifetime of SoftReferences cannot be expressed correctly. "

                        "MaxHeapSize (" SIZE_FORMAT ") or SoftRefLRUPolicyMSPerMB "

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

                        maxHeap, softRef);

    return JVMFlag::VIOLATES_CONSTRAINT;

  } else {

    return JVMFlag::SUCCESS;

  }

}

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

  return CheckMaxHeapSizeAndSoftRefLRUPolicyMSPerMB(MaxHeapSize, value, verbose);

}

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

  if (value > MarkStackSizeMax) {

    JVMFlag::printError(verbose,

                        "MarkStackSize (" SIZE_FORMAT ") must be "

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

                        value, MarkStackSizeMax);

    return JVMFlag::VIOLATES_CONSTRAINT;

  } else {

    return JVMFlag::SUCCESS;

  }

}

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

  if (value > MaxMetaspaceFreeRatio) {

    JVMFlag::printError(verbose,

                        "MinMetaspaceFreeRatio (" UINTX_FORMAT ") must be "

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

                        value, MaxMetaspaceFreeRatio);

    return JVMFlag::VIOLATES_CONSTRAINT;

  } else {

    return JVMFlag::SUCCESS;

  }

}

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

  if (value < MinMetaspaceFreeRatio) {

    JVMFlag::printError(verbose,

                        "MaxMetaspaceFreeRatio (" UINTX_FORMAT ") must be "

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

                        value, MinMetaspaceFreeRatio);

    return JVMFlag::VIOLATES_CONSTRAINT;

  } else {

    return JVMFlag::SUCCESS;

  }

}

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

#if INCLUDE_PARALLELGC

  JVMFlag::Error status = InitialTenuringThresholdConstraintFuncParallel(value, verbose);

  if (status != JVMFlag::SUCCESS) {

    return status;

  }

#endif

  return JVMFlag::SUCCESS;

}

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

#if INCLUDE_PARALLELGC

  JVMFlag::Error status = MaxTenuringThresholdConstraintFuncParallel(value, verbose);

  if (status != JVMFlag::SUCCESS) {

    return status;

  }

#endif

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

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

    JVMFlag::printError(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 JVMFlag::VIOLATES_CONSTRAINT;

  }

  return JVMFlag::SUCCESS;

}

JVMFlag::Error MaxGCPauseMillisConstraintFunc(uintx value, bool verbose) {

#if INCLUDE_G1GC

  JVMFlag::Error status = MaxGCPauseMillisConstraintFuncG1(value, verbose);

  if (status != JVMFlag::SUCCESS) {

    return status;

  }

#endif

  return JVMFlag::SUCCESS;

}

JVMFlag::Error GCPauseIntervalMillisConstraintFunc(uintx value, bool verbose) {

#if INCLUDE_G1GC

  JVMFlag::Error status = GCPauseIntervalMillisConstraintFuncG1(value, verbose);

  if (status != JVMFlag::SUCCESS) {

    return status;

  }

#endif

  return JVMFlag::SUCCESS;

}

JVMFlag::Error InitialBootClassLoaderMetaspaceSizeConstraintFunc(size_t value, bool verbose) {

  size_t aligned_max = align_down(max_uintx/2, Metaspace::reserve_alignment_words());

  if (value > aligned_max) {

    JVMFlag::printError(verbose,

                        "InitialBootClassLoaderMetaspaceSize (" SIZE_FORMAT ") must be "

                        "less than or equal to aligned maximum value (" SIZE_FORMAT ")\n",

                        value, aligned_max);

    return JVMFlag::VIOLATES_CONSTRAINT;

  }

  return JVMFlag::SUCCESS;

}

// To avoid an overflow by 'align_up(value, alignment)'.

static JVMFlag::Error MaxSizeForAlignment(const char* name, size_t value, size_t alignment, bool verbose) {

  size_t aligned_max = ((max_uintx - alignment) & ~(alignment-1));

  if (value > aligned_max) {

    JVMFlag::printError(verbose,

                        "%s (" SIZE_FORMAT ") must be "

                        "less than or equal to aligned maximum value (" SIZE_FORMAT ")\n",

                        name, value, aligned_max);

    return JVMFlag::VIOLATES_CONSTRAINT;

  }

  return JVMFlag::SUCCESS;

}

static JVMFlag::Error MaxSizeForHeapAlignment(const char* name, size_t value, bool verbose) {

  size_t heap_alignment;

#if INCLUDE_G1GC

  if (UseG1GC) {

    // For G1 GC, we don't know until G1CollectorPolicy is created.

    heap_alignment = MaxSizeForHeapAlignmentG1();

  } else

#endif

  {

    heap_alignment = CollectorPolicy::compute_heap_alignment();

  }

  return MaxSizeForAlignment(name, value, heap_alignment, verbose);

}

JVMFlag::Error InitialHeapSizeConstraintFunc(size_t value, bool verbose) {

  return MaxSizeForHeapAlignment("InitialHeapSize", value, verbose);

}

JVMFlag::Error MaxHeapSizeConstraintFunc(size_t value, bool verbose) {

  JVMFlag::Error status = MaxSizeForHeapAlignment("MaxHeapSize", value, verbose);

  if (status == JVMFlag::SUCCESS) {

    status = CheckMaxHeapSizeAndSoftRefLRUPolicyMSPerMB(value, SoftRefLRUPolicyMSPerMB, verbose);

  }

  return status;

}

JVMFlag::Error HeapBaseMinAddressConstraintFunc(size_t value, bool verbose) {

  // If an overflow happened in Arguments::set_heap_size(), MaxHeapSize will have too large a value.

  // Check for this by ensuring that MaxHeapSize plus the requested min base address still fit within max_uintx.

  if (UseCompressedOops && FLAG_IS_ERGO(MaxHeapSize) && (value > (max_uintx - MaxHeapSize))) {

    JVMFlag::printError(verbose,

                        "HeapBaseMinAddress (" SIZE_FORMAT ") or MaxHeapSize (" SIZE_FORMAT ") is too large. "

                        "Sum of them must be less than or equal to maximum of size_t (" SIZE_FORMAT ")\n",

                        value, MaxHeapSize, max_uintx);

    return JVMFlag::VIOLATES_CONSTRAINT;

  }

  return MaxSizeForHeapAlignment("HeapBaseMinAddress", value, verbose);

}

JVMFlag::Error NewSizeConstraintFunc(size_t value, bool verbose) {

#if INCLUDE_G1GC

  JVMFlag::Error status = NewSizeConstraintFuncG1(value, verbose);

  if (status != JVMFlag::SUCCESS) {

    return status;

  }

#endif

  return JVMFlag::SUCCESS;

}

JVMFlag::Error MinTLABSizeConstraintFunc(size_t value, bool verbose) {

  // At least, alignment reserve area is needed.

  if (value < ThreadLocalAllocBuffer::alignment_reserve_in_bytes()) {

    JVMFlag::printError(verbose,

                        "MinTLABSize (" SIZE_FORMAT ") must be "

                        "greater than or equal to reserved area in TLAB (" SIZE_FORMAT ")\n",

                        value, ThreadLocalAllocBuffer::alignment_reserve_in_bytes());

    return JVMFlag::VIOLATES_CONSTRAINT;

  }

  if (value > (ThreadLocalAllocBuffer::max_size() * HeapWordSize)) {

    JVMFlag::printError(verbose,

                        "MinTLABSize (" SIZE_FORMAT ") must be "

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

                        value, ThreadLocalAllocBuffer::max_size() * HeapWordSize);

    return JVMFlag::VIOLATES_CONSTRAINT;

  }

  return JVMFlag::SUCCESS;

}

JVMFlag::Error TLABSizeConstraintFunc(size_t value, bool verbose) {

  // Skip for default value of zero which means set ergonomically.

  if (FLAG_IS_CMDLINE(TLABSize)) {

    if (value < MinTLABSize) {

      JVMFlag::printError(verbose,

                          "TLABSize (" SIZE_FORMAT ") must be "

                          "greater than or equal to MinTLABSize (" SIZE_FORMAT ")\n",

                          value, MinTLABSize);

      return JVMFlag::VIOLATES_CONSTRAINT;

    }

    if (value > (ThreadLocalAllocBuffer::max_size() * HeapWordSize)) {

      JVMFlag::printError(verbose,

                          "TLABSize (" SIZE_FORMAT ") must be "

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

                          value, (ThreadLocalAllocBuffer::max_size() * HeapWordSize));

      return JVMFlag::VIOLATES_CONSTRAINT;

    }

  }

  return JVMFlag::SUCCESS;

}

// We will protect overflow from ThreadLocalAllocBuffer::record_slow_allocation(),

// so AfterMemoryInit type is enough to check.

JVMFlag::Error TLABWasteIncrementConstraintFunc(uintx value, bool verbose) {

  if (UseTLAB) {

    size_t refill_waste_limit = Thread::current()->tlab().refill_waste_limit();

    // Compare with 'max_uintx' as ThreadLocalAllocBuffer::_refill_waste_limit is 'size_t'.

    if (refill_waste_limit > (max_uintx - value)) {

      JVMFlag::printError(verbose,

                          "TLABWasteIncrement (" UINTX_FORMAT ") must be "

                          "less than or equal to ergonomic TLAB waste increment maximum size(" SIZE_FORMAT ")\n",

                          value, (max_uintx - refill_waste_limit));

      return JVMFlag::VIOLATES_CONSTRAINT;

    }

  }

  return JVMFlag::SUCCESS;

}

JVMFlag::Error SurvivorRatioConstraintFunc(uintx value, bool verbose) {

  if (FLAG_IS_CMDLINE(SurvivorRatio) &&

      (value > (MaxHeapSize / Universe::heap()->collector_policy()->space_alignment()))) {

    JVMFlag::printError(verbose,

                        "SurvivorRatio (" UINTX_FORMAT ") must be "

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

                        value,

                        (MaxHeapSize / Universe::heap()->collector_policy()->space_alignment()));

    return JVMFlag::VIOLATES_CONSTRAINT;

  } else {

    return JVMFlag::SUCCESS;

  }

}

JVMFlag::Error MetaspaceSizeConstraintFunc(size_t value, bool verbose) {

  if (value > MaxMetaspaceSize) {

    JVMFlag::printError(verbose,

                        "MetaspaceSize (" SIZE_FORMAT ") must be "

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

                        value, MaxMetaspaceSize);

    return JVMFlag::VIOLATES_CONSTRAINT;

  } else {

    return JVMFlag::SUCCESS;

  }

}

JVMFlag::Error MaxMetaspaceSizeConstraintFunc(size_t value, bool verbose) {

  if (value < MetaspaceSize) {

    JVMFlag::printError(verbose,

                        "MaxMetaspaceSize (" SIZE_FORMAT ") must be "

                        "greater than or equal to MetaspaceSize (" SIZE_FORMAT ")\n",

                        value, MaxMetaspaceSize);

    return JVMFlag::VIOLATES_CONSTRAINT;

  } else {

    return JVMFlag::SUCCESS;

  }

}

JVMFlag::Error SurvivorAlignmentInBytesConstraintFunc(intx value, bool verbose) {

  if (value != 0) {

    if (!is_power_of_2(value)) {

      JVMFlag::printError(verbose,

                          "SurvivorAlignmentInBytes (" INTX_FORMAT ") must be "

                          "power of 2\n",

                          value);

      return JVMFlag::VIOLATES_CONSTRAINT;

    }

    if (value < ObjectAlignmentInBytes) {

      JVMFlag::printError(verbose,

                          "SurvivorAlignmentInBytes (" INTX_FORMAT ") must be "

                          "greater than or equal to ObjectAlignmentInBytes (" INTX_FORMAT ")\n",

                          value, ObjectAlignmentInBytes);

      return JVMFlag::VIOLATES_CONSTRAINT;

    }

  }

  return JVMFlag::SUCCESS;

}