arraypool.h

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#ifndef arraypool_h
#define arraypool_h

// create and manage a vector of arrays as a memory pool of those arrays
// the idea is to allow the possibility of some extra cache efficiency

// the chain of ArrayPool
// is only for extra items in a pool_ and no other fields are used.
// The arraypool can be inceased in size by calling grow(ninc) which
// will chain a new ArrayPool of that size. Note that threads using
// distinct ArrayPool chain items will not have a problem with cache
// line sharing.
// When the arraypool needs to grow itself then it
// doubles in size every time a chain ArrayPool is added.
// maxget() tells the most number of arraypool items used at once.
// note that grow_(ninc) implicitly assumes all existing space is in use
// (i.e. put == get) and hence put ends up as put+ninc. On the other
// hand the user callable grow(ninc) assumes NO space is in use,
// so also put == get and put is set back to get.

#define declareArrayPool(ArrayPool,T) \
class ArrayPool { \
public: \
   ArrayPool(long count, long d2); \
   ~ArrayPool(); \
   T* alloc(); \
   void hpfree(T*); \
   int maxget() { return maxget_;} \
   int size() { return count_;} \
   void free_all(); \
   T* pool() { return pool_; } \
   long get() { return get_; } \
   long put() { return put_; } \
   long nget() { return nget_; } \
   long ntget() { return ntget_; } \
   long d2() { return d2_; } \
   T* element(long i) { return pool_ + i*d2_; } \
   T** items() { return items_; } \
   void grow(long ninc); \
   ArrayPool* chain() { return chain_; } \
   long chain_size() { return pool_size_; } \
private: \
   void grow_(long ninc); \
private: \
   T** items_; \
   T* pool_; \
   long pool_size_; \
   long count_; \
   long get_; \
   long put_; \
   long nget_; \
   long ntget_; \
   long maxget_; \
   long d2_; \
   ArrayPool* chain_; \
   ArrayPool* chainlast_; \
}; \
 \

#define implementArrayPool(ArrayPool,T) \
ArrayPool::ArrayPool(long count, long d2) { \
   count_ = count; \
   d2_ = d2; \
   pool_ = (T*)nrn_cacheline_calloc((void**)&pool_, count_*d2_, sizeof(T)); \
   pool_size_ = count; \
   items_ = new T*[count_]; \
   for (long i = 0; i < count_; ++i) { \
      items_[i] = pool_ + i*d2_; \
   } \
   get_ = 0; \
   put_ = 0; \
   nget_ = 0; \
   ntget_ = 0; \
   maxget_ = 0; \
   chain_ = 0; \
   chainlast_ = this; \
} \
 \
void ArrayPool::grow(long ninc) { \
   grow_(ninc); \
   put_ = get_; \
} \
 \
void ArrayPool::grow_(long ninc) { \
   assert(get_ == put_); \
   ArrayPool* p = new ArrayPool(ninc, d2_); \
   chainlast_->chain_ = p; \
   chainlast_ = p; \
   long newcnt = count_ + ninc; \
   T** itms = new T*[newcnt]; \
   long i, j; \
   put_ += ninc; \
   for (i = 0; i < get_; ++i) { \
      itms[i] = items_[i]; \
   } \
   for (i = get_, j = 0; j < ninc; ++i, ++j) { \
      itms[i] = p->items_[j]; \
   } \
   for (i = put_, j = get_; j < count_; ++i, ++j) { \
      itms[i] = items_[j]; \
   } \
   delete [] items_; \
   delete [] p->items_; \
   p->items_ = 0; \
   items_ = itms; \
   count_ = newcnt; \
} \
 \
ArrayPool::~ArrayPool() { \
   if (chain_) { \
      delete chain_; \
   } \
   free(pool_); \
   if (items_) { \
      delete [] items_; \
   } \
} \
 \
T* ArrayPool::alloc() { \
   if (nget_ >= count_) { grow_(count_); } \
   T* item = items_[get_]; \
   get_ = (get_+1)%count_; \
   ++nget_; \
   ++ntget_; \
   if (nget_ > maxget_) { maxget_ = nget_; } \
   return item; \
} \
 \
void ArrayPool::hpfree(T* item) { \
   assert(nget_ > 0); \
   items_[put_] = item; \
   put_ = (put_ + 1)%count_; \
   --nget_; \
} \
 \
void ArrayPool::free_all() { \
   ArrayPool* pp; \
   long i; \
   nget_ = 0; \
   get_ = 0; \
   put_ = 0; \
   for(pp = this; pp; pp = pp->chain_) { \
      for (i=0; i < pp->pool_size_; ++i) { \
         items_[put_++] = pp->pool_ + i*d2_; \
      } \
   } \
   assert(put_ == count_); \
   put_ = 0; \
} \
 \

#endif