1 /*
   2  * Copyright (c) 2017, 2019, 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 #include "precompiled.hpp"
  25 #include "gc/z/zAddressSpaceLimit.hpp"
  26 #include "gc/z/zArguments.hpp"
  27 #include "gc/z/zCollectedHeap.hpp"
  28 #include "gc/z/zHeuristics.hpp"
  29 #include "gc/shared/gcArguments.hpp"
  30 #include "runtime/globals.hpp"
  31 
  32 void ZArguments::initialize_alignments() {
  33   SpaceAlignment = ZGranuleSize;
  34   HeapAlignment = SpaceAlignment;
  35 }
  36 
  37 void ZArguments::initialize() {
  38   GCArguments::initialize();
  39 
  40   // Check mark stack size
  41   const size_t mark_stack_space_limit = ZAddressSpaceLimit::mark_stack();
  42   if (ZMarkStackSpaceLimit > mark_stack_space_limit) {
  43     if (!FLAG_IS_DEFAULT(ZMarkStackSpaceLimit)) {
  44       vm_exit_during_initialization("ZMarkStackSpaceLimit too large for limited address space");
  45     }
  46     FLAG_SET_DEFAULT(ZMarkStackSpaceLimit, mark_stack_space_limit);
  47   }
  48 
  49   // Enable NUMA by default
  50   if (FLAG_IS_DEFAULT(UseNUMA)) {
  51     FLAG_SET_DEFAULT(UseNUMA, true);
  52   }
  53 
  54   // Disable biased locking by default
  55   if (FLAG_IS_DEFAULT(UseBiasedLocking)) {
  56     FLAG_SET_DEFAULT(UseBiasedLocking, false);
  57   }
  58 
  59   // Select number of parallel threads
  60   if (FLAG_IS_DEFAULT(ParallelGCThreads)) {
  61     FLAG_SET_DEFAULT(ParallelGCThreads, ZHeuristics::nparallel_workers());
  62   }
  63 
  64   if (ParallelGCThreads == 0) {
  65     vm_exit_during_initialization("The flag -XX:+UseZGC can not be combined with -XX:ParallelGCThreads=0");
  66   }
  67 
  68   // Select number of concurrent threads
  69   if (FLAG_IS_DEFAULT(ConcGCThreads)) {
  70     FLAG_SET_DEFAULT(ConcGCThreads, ZHeuristics::nconcurrent_workers());
  71   }
  72 
  73   if (ConcGCThreads == 0) {
  74     vm_exit_during_initialization("The flag -XX:+UseZGC can not be combined with -XX:ConcGCThreads=0");
  75   }
  76 
  77 #ifdef COMPILER2
  78   // Enable loop strip mining by default
  79   if (FLAG_IS_DEFAULT(UseCountedLoopSafepoints)) {
  80     FLAG_SET_DEFAULT(UseCountedLoopSafepoints, true);
  81     if (FLAG_IS_DEFAULT(LoopStripMiningIter)) {
  82       FLAG_SET_DEFAULT(LoopStripMiningIter, 1000);
  83     }
  84   }
  85 #endif
  86 
  87   // CompressedOops/UseCompressedClassPointers not supported
  88   FLAG_SET_DEFAULT(UseCompressedOops, false);
  89   FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
  90 
  91   // Verification before startup and after exit not (yet) supported
  92   FLAG_SET_DEFAULT(VerifyDuringStartup, false);
  93   FLAG_SET_DEFAULT(VerifyBeforeExit, false);
  94 
  95   // Verification before heap iteration not (yet) supported, for the
  96   // same reason we need fixup_partial_loads
  97   FLAG_SET_DEFAULT(VerifyBeforeIteration, false);
  98 
  99   if (VerifyBeforeGC || VerifyDuringGC || VerifyAfterGC) {
 100     FLAG_SET_DEFAULT(ZVerifyRoots, true);
 101     FLAG_SET_DEFAULT(ZVerifyObjects, true);
 102   }
 103 
 104   // Verification of stacks not (yet) supported, for the same reason
 105   // we need fixup_partial_loads
 106   DEBUG_ONLY(FLAG_SET_DEFAULT(VerifyStack, false));
 107 
 108   // Initialize platform specific arguments
 109   initialize_platform();
 110 }
 111 
 112 size_t ZArguments::conservative_max_heap_alignment() {
 113   return 0;
 114 }
 115 
 116 CollectedHeap* ZArguments::create_heap() {
 117   return new ZCollectedHeap();
 118 }
 119 
 120 bool ZArguments::is_supported() const {
 121   return is_os_supported();
 122 }