0N/A

0N/A#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCREGION_HPP

0N/A#define SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCREGION_HPP

0N/A

0N/A#include "gc_implementation/g1/heapRegion.hpp"

0N/A

0N/Aclass G1CollectedHeap;

0N/A

0N/A#define G1_ALLOC_REGION_TRACING 0

0N/A

0N/Aclass ar_ext_msg;

0N/A

0N/A

0N/Aclass G1AllocRegion VALUE_OBJ_CLASS_SPEC {

0N/A friend class ar_ext_msg;

0N/A

0N/Aprivate:

0N/A // The active allocating region we are currently allocating out

5335N/A // of. The invariant is that if this object is initialized (i.e.,

0N/A // init() has been called and release() has not) then _alloc_region

0N/A // is either an active allocating region or the dummy region (i.e.,

0N/A // it can never be NULL) and this object can be used to satisfy

0N/A // allocation requests. If this object is not initialized

0N/A // (i.e. init() has not been called or release() has been called)

0N/A // then _alloc_region is NULL and this object should not be used to

0N/A // satisfy allocation requests (it was done this way to force the

0N/A // correct use of init() and release()).

0N/A HeapRegion* _alloc_region;

0N/A

0N/A // It keeps track of the distinct number of regions that are used

5335N/A // for allocation in the active interval of this object, i.e.,

0N/A // between a call to init() and a call to release(). The count

0N/A // mostly includes regions that are freshly allocated, as well as

0N/A // the region that is re-used using the set() method. This count can

0N/A // be used in any heuristics that might want to bound how many

0N/A // distinct regions this object can used during an active interval.

0N/A uint _count;

0N/A

0N/A // When we set up a new active region we save its used bytes in this

0N/A // field so that, when we retire it, we can calculate how much space

0N/A // we allocated in it.

5335N/A size_t _used_bytes_before;

0N/A

0N/A // When true, indicates that allocate calls should do BOT updates.

5335N/A const bool _bot_updates;

0N/A

0N/A // Useful for debugging and tracing.

0N/A const char* _name;

0N/A

0N/A // A dummy region (i.e., it's been allocated specially for this

0N/A // purpose and it is not part of the heap) that is full (i.e., top()

0N/A // == end()). When we don't have a valid active region we make

0N/A // _alloc_region point to this. This allows us to skip checking

5335N/A // whether the _alloc_region is NULL or not.

0N/A static HeapRegion* _dummy_region;

5335N/A

0N/A // Some of the methods below take a bot_updates parameter. Its value

5335N/A // should be the same as the _bot_updates field. The idea is that

0N/A // the parameter will be a constant for a particular alloc region

0N/A // and, given that these methods will be hopefully inlined, the

0N/A // compiler should compile out the test.

0N/A

0N/A // Perform a non-MT-safe allocation out of the given region.

0N/A static inline HeapWord* allocate(HeapRegion* alloc_region,

0N/A size_t word_size,

0N/A bool bot_updates);

0N/A

0N/A // Perform a MT-safe allocation out of the given region.

0N/A static inline HeapWord* par_allocate(HeapRegion* alloc_region,

0N/A size_t word_size,

0N/A bool bot_updates);

0N/A

0N/A // Ensure that the region passed as a parameter has been filled up

0N/A // so that noone else can allocate out of it any more.

0N/A static void fill_up_remaining_space(HeapRegion* alloc_region,

0N/A bool bot_updates);

0N/A

0N/A // Retire the active allocating region. If fill_up is true then make

0N/A // sure that the region is full before we retire it so that noone

0N/A // else can allocate out of it.

0N/A void retire(bool fill_up);

0N/A

0N/A // Allocate a new active region and use it to perform a word_size

0N/A // allocation. The force parameter will be passed on to

0N/A // G1CollectedHeap::allocate_new_alloc_region() and tells it to try

0N/A // to allocate a new region even if the max has been reached.

0N/A HeapWord* new_alloc_region_and_allocate(size_t word_size, bool force);

0N/A

0N/A void fill_in_ext_msg(ar_ext_msg* msg, const char* message);

0N/A

0N/Aprotected:

0N/A // For convenience as subclasses use it.

0N/A static G1CollectedHeap* _g1h;

0N/A

0N/A virtual HeapRegion* allocate_new_region(size_t word_size, bool force) = 0;

0N/A virtual void retire_region(HeapRegion* alloc_region,

0N/A size_t allocated_bytes) = 0;

0N/A

0N/A G1AllocRegion(const char* name, bool bot_updates);

0N/A

0N/Apublic:

5335N/A static void setup(G1CollectedHeap* g1h, HeapRegion* dummy_region);

5335N/A

0N/A HeapRegion* get() const {

0N/A // Make sure that the dummy region does not escape this class.

0N/A return (_alloc_region == _dummy_region) ? NULL : _alloc_region;

0N/A }

0N/A

0N/A uint count() { return _count; }

0N/A

0N/A // The following two are the building blocks for the allocation method.

0N/A

0N/A // First-level allocation: Should be called without holding a

0N/A // lock. It will try to allocate lock-free out of the active region,

0N/A // or return NULL if it was unable to.

0N/A inline HeapWord* attempt_allocation(size_t word_size, bool bot_updates);

0N/A

0N/A // Second-level allocation: Should be called while holding a

0N/A // lock. It will try to first allocate lock-free out of the active

0N/A // region or, if it's unable to, it will try to replace the active

0N/A // alloc region with a new one. We require that the caller takes the

0N/A // appropriate lock before calling this so that it is easier to make

0N/A // it conform to its locking protocol.

0N/A inline HeapWord* attempt_allocation_locked(size_t word_size,

0N/A bool bot_updates);

0N/A

0N/A // Should be called to allocate a new region even if the max of this

0N/A // type of regions has been reached. Should only be called if other

0N/A // allocation attempts have failed and we are not holding a valid

0N/A // active region.

0N/A inline HeapWord* attempt_allocation_force(size_t word_size,

5335N/A bool bot_updates);

0N/A

5335N/A // Should be called before we start using this object.

0N/A void init();

0N/A

0N/A // This can be used to set the active region to a specific

0N/A // region. (Use Example: we try to retain the last old GC alloc

0N/A // region that we've used during a GC and we can use set() to

0N/A // re-instate it at the beginning of the next GC.)

0N/A void set(HeapRegion* alloc_region);

0N/A

0N/A // Should be called when we want to release the active region which

0N/A // is returned after it's been retired.

0N/A HeapRegion* release();

0N/A

0N/A#if G1_ALLOC_REGION_TRACING

0N/A void trace(const char* str, size_t word_size = 0, HeapWord* result = NULL);

0N/A#else // G1_ALLOC_REGION_TRACING

0N/A void trace(const char* str, size_t word_size = 0, HeapWord* result = NULL) { }

0N/A#endif // G1_ALLOC_REGION_TRACING

0N/A};

0N/A

0N/Aclass ar_ext_msg : public err_msg {

0N/Apublic:

0N/A ar_ext_msg(G1AllocRegion* alloc_region, const char *message) : err_msg("") {

0N/A alloc_region->fill_in_ext_msg(this, message);

0N/A }

0N/A};

0N/A

0N/A#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCREGION_HPP

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