--- old/src/share/vm/gc_implementation/g1/g1AllocRegion.hpp 2015-05-13 13:55:15.817174461 +0200 +++ /dev/null 2015-03-18 17:10:38.111854831 +0100 @@ -1,236 +0,0 @@ -/* - * 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; - - // Allocation context associated with this alloc region. - AllocationContext_t _allocation_context; - - // 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); - - // After a region is allocated by alloc_new_region, this - // method is used to set it as the active alloc_region - void update_alloc_region(HeapRegion* alloc_region); - - // 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; - } - - void set_allocation_context(AllocationContext_t context) { _allocation_context = context; } - AllocationContext_t allocation_context() { return _allocation_context; } - - 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. - virtual 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 MutatorAllocRegion : public G1AllocRegion { -protected: - virtual HeapRegion* allocate_new_region(size_t word_size, bool force); - virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); -public: - MutatorAllocRegion() - : G1AllocRegion("Mutator Alloc Region", false /* bot_updates */) { } -}; - -class SurvivorGCAllocRegion : public G1AllocRegion { -protected: - virtual HeapRegion* allocate_new_region(size_t word_size, bool force); - virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); -public: - SurvivorGCAllocRegion() - : G1AllocRegion("Survivor GC Alloc Region", false /* bot_updates */) { } -}; - -class OldGCAllocRegion : public G1AllocRegion { -protected: - virtual HeapRegion* allocate_new_region(size_t word_size, bool force); - virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); -public: - OldGCAllocRegion() - : G1AllocRegion("Old GC Alloc Region", true /* bot_updates */) { } - - // This specialization of release() makes sure that the last card that has - // been allocated into has been completely filled by a dummy object. This - // avoids races when remembered set scanning wants to update the BOT of the - // last card in the retained old gc alloc region, and allocation threads - // allocating into that card at the same time. - virtual HeapRegion* release(); -}; - -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 --- /dev/null 2015-03-18 17:10:38.111854831 +0100 +++ new/src/share/vm/gc/g1/g1AllocRegion.hpp 2015-05-13 13:55:15.100144708 +0200 @@ -0,0 +1,236 @@ +/* + * Copyright (c) 2011, 2015, 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_G1_G1ALLOCREGION_HPP +#define SHARE_VM_GC_G1_G1ALLOCREGION_HPP + +#include "gc/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; + + // Allocation context associated with this alloc region. + AllocationContext_t _allocation_context; + + // 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); + + // After a region is allocated by alloc_new_region, this + // method is used to set it as the active alloc_region + void update_alloc_region(HeapRegion* alloc_region); + + // 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; + } + + void set_allocation_context(AllocationContext_t context) { _allocation_context = context; } + AllocationContext_t allocation_context() { return _allocation_context; } + + 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. + virtual 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 MutatorAllocRegion : public G1AllocRegion { +protected: + virtual HeapRegion* allocate_new_region(size_t word_size, bool force); + virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); +public: + MutatorAllocRegion() + : G1AllocRegion("Mutator Alloc Region", false /* bot_updates */) { } +}; + +class SurvivorGCAllocRegion : public G1AllocRegion { +protected: + virtual HeapRegion* allocate_new_region(size_t word_size, bool force); + virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); +public: + SurvivorGCAllocRegion() + : G1AllocRegion("Survivor GC Alloc Region", false /* bot_updates */) { } +}; + +class OldGCAllocRegion : public G1AllocRegion { +protected: + virtual HeapRegion* allocate_new_region(size_t word_size, bool force); + virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes); +public: + OldGCAllocRegion() + : G1AllocRegion("Old GC Alloc Region", true /* bot_updates */) { } + + // This specialization of release() makes sure that the last card that has + // been allocated into has been completely filled by a dummy object. This + // avoids races when remembered set scanning wants to update the BOT of the + // last card in the retained old gc alloc region, and allocation threads + // allocating into that card at the same time. + virtual HeapRegion* release(); +}; + +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_G1_G1ALLOCREGION_HPP