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
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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
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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
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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 
conservative_max_heap_alignment()34 size_t ZArguments::conservative_max_heap_alignment() {
35   return 0;
36 }
37 
initialize()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   // To avoid asserts in set_active_workers()
80   FLAG_SET_DEFAULT(UseDynamicNumberOfGCThreads, true);
81 
82   // CompressedOops/UseCompressedClassPointers not supported
83   FLAG_SET_DEFAULT(UseCompressedOops, false);
84   FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
85 
86   // ClassUnloading not (yet) supported
87   FLAG_SET_DEFAULT(ClassUnloading, false);
88   FLAG_SET_DEFAULT(ClassUnloadingWithConcurrentMark, false);
89 
90   // Verification before startup and after exit not (yet) supported
91   FLAG_SET_DEFAULT(VerifyDuringStartup, false);
92   FLAG_SET_DEFAULT(VerifyBeforeExit, false);
93 
94   // Verification before heap iteration not (yet) supported, for the
95   // same reason we need fixup_partial_loads
96   FLAG_SET_DEFAULT(VerifyBeforeIteration, false);
97 
98   // Verification of stacks not (yet) supported, for the same reason
99   // we need fixup_partial_loads
100   DEBUG_ONLY(FLAG_SET_DEFAULT(VerifyStack, false));
101 }
102 
create_heap()103 CollectedHeap* ZArguments::create_heap() {
104   return create_heap_with_policy<ZCollectedHeap, ZCollectorPolicy>();
105 }
106