jdk8-mips64-public/hotspot: comparison src/share/vm/gc

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+/*
+* Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
+* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+*
+* 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.
+*
+*/
+#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCREGION_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCREGION_HPP
+#include "gc_implementation/g1/heapRegion.hpp"
+class G1CollectedHeap;
+// 0 -> no tracing, 1 -> basic tracing, 2 -> basic + allocation tracing
+#define G1_ALLOC_REGION_TRACING 0
+class ar_ext_msg;
+// A class that holds a region that is active in satisfying allocation
+// requests, potentially issued in parallel. When the active region is
+// full it will be retired and replaced with a new one. The
+// implementation assumes that fast-path allocations will be lock-free
+// and a lock will need to be taken when the active region needs to be
+// replaced.
+class G1AllocRegion VALUE_OBJ_CLASS_SPEC {
+friend class ar_ext_msg;
+private:
+// The active allocating region we are currently allocating out
+// of. The invariant is that if this object is initialized (i.e.,
+// init() has been called and release() has not) then _alloc_region
+// is either an active allocating region or the dummy region (i.e.,
+// it can never be NULL) and this object can be used to satisfy
+// allocation requests. If this object is not initialized
+// (i.e. init() has not been called or release() has been called)
+// then _alloc_region is NULL and this object should not be used to
+// satisfy allocation requests (it was done this way to force the
+// correct use of init() and release()).
+HeapRegion* volatile _alloc_region;
+// It keeps track of the distinct number of regions that are used
+// for allocation in the active interval of this object, i.e.,
+// between a call to init() and a call to release(). The count
+// mostly includes regions that are freshly allocated, as well as
+// the region that is re-used using the set() method. This count can
+// be used in any heuristics that might want to bound how many
+// distinct regions this object can used during an active interval.
+uint _count;
+// When we set up a new active region we save its used bytes in this
+// field so that, when we retire it, we can calculate how much space
+// we allocated in it.
+size_t _used_bytes_before;
+// When true, indicates that allocate calls should do BOT updates.
+const bool _bot_updates;
+// Useful for debugging and tracing.
+const char* _name;
+// A dummy region (i.e., it's been allocated specially for this
+// purpose and it is not part of the heap) that is full (i.e., top()
+// == end()). When we don't have a valid active region we make
+// _alloc_region point to this. This allows us to skip checking
+// whether the _alloc_region is NULL or not.
+static HeapRegion* _dummy_region;
+// Some of the methods below take a bot_updates parameter. Its value
+// should be the same as the _bot_updates field. The idea is that
+// the parameter will be a constant for a particular alloc region
+// and, given that these methods will be hopefully inlined, the
+// compiler should compile out the test.
+// Perform a non-MT-safe allocation out of the given region.
+static inline HeapWord* allocate(HeapRegion* alloc_region,
+size_t word_size,
+bool bot_updates);
+// Perform a MT-safe allocation out of the given region.
+static inline HeapWord* par_allocate(HeapRegion* alloc_region,
+size_t word_size,
+bool bot_updates);
+// Ensure that the region passed as a parameter has been filled up
+// so that noone else can allocate out of it any more.
+static void fill_up_remaining_space(HeapRegion* alloc_region,
+bool bot_updates);
+// Retire the active allocating region. If fill_up is true then make
+// sure that the region is full before we retire it so that noone
+// else can allocate out of it.
+void retire(bool fill_up);
+// Allocate a new active region and use it to perform a word_size
+// allocation. The force parameter will be passed on to
+// G1CollectedHeap::allocate_new_alloc_region() and tells it to try
+// to allocate a new region even if the max has been reached.
+HeapWord* new_alloc_region_and_allocate(size_t word_size, bool force);
+void fill_in_ext_msg(ar_ext_msg* msg, const char* message);
+protected:
+// For convenience as subclasses use it.
+static G1CollectedHeap* _g1h;
+virtual HeapRegion* allocate_new_region(size_t word_size, bool force) = 0;
+virtual void retire_region(HeapRegion* alloc_region,
+size_t allocated_bytes) = 0;
+G1AllocRegion(const char* name, bool bot_updates);
+public:
+static void setup(G1CollectedHeap* g1h, HeapRegion* dummy_region);
+HeapRegion* get() const {
+HeapRegion * hr = _alloc_region;
+// Make sure that the dummy region does not escape this class.
+return (hr == _dummy_region) ? NULL : hr;
+}
+uint count() { return _count; }
+// The following two are the building blocks for the allocation method.
+// First-level allocation: Should be called without holding a
+// lock. It will try to allocate lock-free out of the active region,
+// or return NULL if it was unable to.
+inline HeapWord* attempt_allocation(size_t word_size, bool bot_updates);
+// Second-level allocation: Should be called while holding a
+// lock. It will try to first allocate lock-free out of the active
+// region or, if it's unable to, it will try to replace the active
+// alloc region with a new one. We require that the caller takes the
+// appropriate lock before calling this so that it is easier to make
+// it conform to its locking protocol.
+inline HeapWord* attempt_allocation_locked(size_t word_size,
+bool bot_updates);
+// Should be called to allocate a new region even if the max of this
+// type of regions has been reached. Should only be called if other
+// allocation attempts have failed and we are not holding a valid
+// active region.
+inline HeapWord* attempt_allocation_force(size_t word_size,
+bool bot_updates);
+// Should be called before we start using this object.
+void init();
+// This can be used to set the active region to a specific
+// region. (Use Example: we try to retain the last old GC alloc
+// region that we've used during a GC and we can use set() to
+// re-instate it at the beginning of the next GC.)
+void set(HeapRegion* alloc_region);
+// Should be called when we want to release the active region which
+// is returned after it's been retired.
+HeapRegion* release();
+#if G1_ALLOC_REGION_TRACING
+void trace(const char* str, size_t word_size = 0, HeapWord* result = NULL);
+#else // G1_ALLOC_REGION_TRACING
+void trace(const char* str, size_t word_size = 0, HeapWord* result = NULL) { }
+#endif // G1_ALLOC_REGION_TRACING
+};
+class ar_ext_msg : public err_msg {
+public:
+ar_ext_msg(G1AllocRegion* alloc_region, const char *message) : err_msg("%s", "") {
+alloc_region->fill_in_ext_msg(this, message);
+}
+};
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCREGION_HPP

comparison: src/share/vm/gc_implementation/g1/g1AllocRegion.hpp

src/share/vm/gc_implementation/g1/g1AllocRegion.hpp

Mercurial > jdk8-mips64-public > hotspot / file comparison

comparison: src/share/vm/gc_implementation/g1/g1AllocRegion.hpp

src/share/vm/gc_implementation/g1/g1AllocRegion.hpp