--- /dev/null 2017-02-09 18:28:35.238523416 +0100 +++ new/src/share/vm/gc/epsilon/epsilonCollectedHeap.hpp 2017-02-13 23:17:57.746243165 +0100 @@ -0,0 +1,151 @@ +/* + * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * 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 + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "gc/shared/collectedHeap.hpp" +#include "gc/epsilon/epsilonCollectorPolicy.hpp" +#include "gc/epsilon/epsilonBarrierSet.hpp" + +class EpsilonCollectedHeap : public CollectedHeap { +private: + EpsilonCollectorPolicy* _policy; + HeapWord* _start; + HeapWord* _end; + volatile HeapWord* _current; +public: + EpsilonCollectedHeap(EpsilonCollectorPolicy* p) : _policy(p) {}; + + virtual Name kind() const { + return CollectedHeap::EpsilonCollectedHeap; + } + + virtual const char *name() const { + return "Epsilon GC"; + } + + virtual jint initialize(); + + virtual void post_initialize() {} + + virtual size_t capacity() const { return pointer_delta(_end, _start); } + virtual size_t used() const { return pointer_delta((HeapWord*)_current, _start); } + virtual size_t max_capacity() const { return capacity(); } + + virtual bool is_maximal_no_gc() const { return used() == capacity(); } // TODO: Really? + + virtual bool is_in(const void *p) const { return (_start <= p) && (p < _end); } + + virtual bool is_scavengable(const void *p) { return true; } // TODO: Why? + + virtual HeapWord* mem_allocate(size_t size, bool *gc_overhead_limit_was_exceeded); + virtual HeapWord* allocate_new_tlab(size_t size); + + virtual HeapWord* allocate_work(size_t size); + + // TLAB allocations + virtual bool supports_tlab_allocation() const { return true; } + virtual size_t tlab_capacity(Thread *thr) const { return capacity(); } + virtual size_t tlab_used(Thread *thr) const { return used(); } // TODO: Should probably record the TLAB? + virtual size_t unsafe_max_tlab_alloc(Thread *thr) const { + // TODO: hook up in TLAB policy better. pointer_delta(_current, _end); + return HeapWordSize * 128 * K; + } + + virtual bool can_elide_tlab_store_barriers() const { + return true; // TODO: Really? + } + + virtual bool can_elide_initializing_store_barrier(oop new_obj) { + return true; // TODO: Really? + } + + virtual bool card_mark_must_follow_store() const { + return true; // TODO: Really? + } + + virtual void collect(GCCause::Cause cause); + virtual void do_full_collection(bool clear_all_soft_refs); + + virtual AdaptiveSizePolicy *size_policy() { + // No such thing for Epsilon + return NULL; + } + + virtual CollectorPolicy *collector_policy() const { + return _policy; + } + + virtual void object_iterate(ObjectClosure *cl) { + safe_object_iterate(cl); + } + + virtual void safe_object_iterate(ObjectClosure *cl); + + virtual HeapWord *block_start(const void *addr) const { + Unimplemented(); + return NULL; + } + + virtual size_t block_size(const HeapWord *addr) const { + Unimplemented(); + return 0; + } + + virtual bool block_is_obj(const HeapWord *addr) const { + Unimplemented(); + return false; + } + + virtual jlong millis_since_last_gc() { + return os::elapsed_counter() / NANOSECS_PER_MILLISEC; // since the VM start + } + + virtual void prepare_for_verify() { + // No heap verification. + } + + virtual void print_on(outputStream *st) const { + // Print nothing. + } + + virtual void print_gc_threads_on(outputStream *st) const { + // No GC threads. + } + + virtual void gc_threads_do(ThreadClosure *tc) const { + // No GC threads. + } + + virtual void print_tracing_info() const { + Log(gc) log; + size_t allocated_kb = pointer_delta((HeapWord*)_current, _start) * HeapWordSize / K; + log.info("Total allocated: " SIZE_FORMAT " KB.", + allocated_kb); + log.info("Average allocation rate: " SIZE_FORMAT " KB/sec", + allocated_kb * NANOSECS_PER_SEC / os::elapsed_counter()); + } + + virtual void verify(VerifyOption option) { + // No heap verification for Epsilon. + } + +};