1 /*
   2  * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "gc/z/zArguments.hpp"
  27 #include "gc/z/zCollectedHeap.hpp"
  28 #include "gc/z/zCollectorPolicy.hpp"
  29 #include "gc/z/zWorkers.hpp"
  30 #include "gc/shared/gcArguments.inline.hpp"
  31 #include "runtime/globals.hpp"
  32 #include "runtime/globals_extension.hpp"
  33 
  34 size_t ZArguments::conservative_max_heap_alignment() {
  35   return 0;
  36 }
  37 
  38 void ZArguments::initialize() {
  39   GCArguments::initialize();
  40 
  41   // Enable NUMA by default
  42   if (FLAG_IS_DEFAULT(UseNUMA)) {
  43     FLAG_SET_DEFAULT(UseNUMA, true);
  44   }
  45 
  46   // Disable biased locking by default
  47   if (FLAG_IS_DEFAULT(UseBiasedLocking)) {
  48     FLAG_SET_DEFAULT(UseBiasedLocking, false);
  49   }
  50 
  51   // Select number of parallel threads
  52   if (FLAG_IS_DEFAULT(ParallelGCThreads)) {
  53     FLAG_SET_DEFAULT(ParallelGCThreads, ZWorkers::calculate_nparallel());
  54   }
  55 
  56   if (ParallelGCThreads == 0) {
  57     vm_exit_during_initialization("The flag -XX:+UseZGC can not be combined with -XX:ParallelGCThreads=0");
  58   }
  59 
  60   // Select number of concurrent threads
  61   if (FLAG_IS_DEFAULT(ConcGCThreads)) {
  62     FLAG_SET_DEFAULT(ConcGCThreads, ZWorkers::calculate_nconcurrent());
  63   }
  64 
  65   if (ConcGCThreads == 0) {
  66     vm_exit_during_initialization("The flag -XX:+UseZGC can not be combined with -XX:ConcGCThreads=0");
  67   }
  68 
  69 #ifdef COMPILER2
  70   // Enable loop strip mining by default
  71   if (FLAG_IS_DEFAULT(UseCountedLoopSafepoints)) {
  72     FLAG_SET_DEFAULT(UseCountedLoopSafepoints, true);
  73     if (FLAG_IS_DEFAULT(LoopStripMiningIter)) {
  74       FLAG_SET_DEFAULT(LoopStripMiningIter, 1000);
  75     }
  76   }
  77 #endif
  78 
  79   // CompressedOops/UseCompressedClassPointers not supported
  80   FLAG_SET_DEFAULT(UseCompressedOops, false);
  81   FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
  82 
  83   // Verification before startup and after exit not (yet) supported
  84   FLAG_SET_DEFAULT(VerifyDuringStartup, false);
  85   FLAG_SET_DEFAULT(VerifyBeforeExit, false);
  86 
  87   // Verification before heap iteration not (yet) supported, for the
  88   // same reason we need fixup_partial_loads
  89   FLAG_SET_DEFAULT(VerifyBeforeIteration, false);
  90 
  91   // Verification of stacks not (yet) supported, for the same reason
  92   // we need fixup_partial_loads
  93   DEBUG_ONLY(FLAG_SET_DEFAULT(VerifyStack, false));
  94 }
  95 
  96 CollectedHeap* ZArguments::create_heap() {
  97   return create_heap_with_policy<ZCollectedHeap, ZCollectorPolicy>();
  98 }