hotspot/src/share/vm/runtime/commandLineFlagConstraintsRuntime.cpp
author dcubed
Thu, 03 Sep 2015 10:22:39 -0700
changeset 32614 b7b2407bc7e5
parent 32351 1da9b960b3d4
child 33222 e0a340f4ab6e
permissions -rw-r--r--
8049304: race between VM_Exit and _sync_FutileWakeups->inc() Summary: Add PerfDataManager.has_PerfData() to indicate when PerfData objects should be safe to query. Update Java monitor PerfData usage to check the new flag. PerfDataManager::destroy() should only be called at a safepoint and when the StatSampler is not active. Reviewed-by: kbarrett, dholmes, tbenson, bdelsart

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#include "precompiled.hpp"
#include "runtime/arguments.hpp"
#include "runtime/commandLineFlagConstraintsRuntime.hpp"
#include "runtime/commandLineFlagRangeList.hpp"
#include "runtime/globals.hpp"
#include "utilities/defaultStream.hpp"

Flag::Error ObjectAlignmentInBytesConstraintFunc(intx value, bool verbose) {
  if (!is_power_of_2(value)) {
    CommandLineError::print(verbose,
                            "ObjectAlignmentInBytes (" INTX_FORMAT ") must be "
                            "power of 2\n",
                            value);
    return Flag::VIOLATES_CONSTRAINT;
  }
  // In case page size is very small.
  if (value >= (intx)os::vm_page_size()) {
    CommandLineError::print(verbose,
                            "ObjectAlignmentInBytes (" INTX_FORMAT ") must be "
                            "less than page size " INTX_FORMAT "\n",
                            value, (intx)os::vm_page_size());
    return Flag::VIOLATES_CONSTRAINT;
  }
  return Flag::SUCCESS;
}

// Need to enforce the padding not to break the existing field alignments.
// It is sufficient to check against the largest type size.
Flag::Error ContendedPaddingWidthConstraintFunc(intx value, bool verbose) {
  if ((value != 0) && ((value % BytesPerLong) != 0)) {
    CommandLineError::print(verbose,
                            "ContendedPaddingWidth (" INTX_FORMAT ") must be "
                            "a multiple of %d\n",
                            value, BytesPerLong);
    return Flag::VIOLATES_CONSTRAINT;
  } else {
    return Flag::SUCCESS;
  }
}