8204180: Implementation: JEP 318: Epsilon, A No-Op Garbage Collector
Summary: Introduce Epsilon GC
Reviewed-by: rkennke, ihse, pliden, eosterlund, lmesnik, jgeorge, stefank
/*
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* 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
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#include "precompiled.hpp"
#include "gc/epsilon/epsilonArguments.hpp"
#include "gc/epsilon/epsilonHeap.hpp"
#include "gc/epsilon/epsilonCollectorPolicy.hpp"
#include "gc/shared/gcArguments.inline.hpp"
#include "runtime/globals.hpp"
#include "runtime/globals_extension.hpp"
#include "runtime/vm_version.hpp"
#include "utilities/macros.hpp"
size_t EpsilonArguments::conservative_max_heap_alignment() {
return UseLargePages ? os::large_page_size() : os::vm_page_size();
}
void EpsilonArguments::initialize() {
GCArguments::initialize();
assert(UseEpsilonGC, "Sanity");
// Forcefully exit when OOME is detected. Nothing we can do at that point.
if (FLAG_IS_DEFAULT(ExitOnOutOfMemoryError)) {
FLAG_SET_DEFAULT(ExitOnOutOfMemoryError, true);
}
if (EpsilonMaxTLABSize < MinTLABSize) {
warning("EpsilonMaxTLABSize < MinTLABSize, adjusting it to " SIZE_FORMAT, MinTLABSize);
EpsilonMaxTLABSize = MinTLABSize;
}
if (!EpsilonElasticTLAB && EpsilonElasticTLABDecay) {
warning("Disabling EpsilonElasticTLABDecay because EpsilonElasticTLAB is disabled");
FLAG_SET_DEFAULT(EpsilonElasticTLABDecay, false);
}
#ifdef COMPILER2
// Enable loop strip mining: there are still non-GC safepoints, no need to make it worse
if (FLAG_IS_DEFAULT(UseCountedLoopSafepoints)) {
FLAG_SET_DEFAULT(UseCountedLoopSafepoints, true);
if (FLAG_IS_DEFAULT(LoopStripMiningIter)) {
FLAG_SET_DEFAULT(LoopStripMiningIter, 1000);
}
}
#endif
}
CollectedHeap* EpsilonArguments::create_heap() {
return create_heap_with_policy<EpsilonHeap, EpsilonCollectorPolicy>();
}