structpool.h

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#ifndef structpool_h
#define structpool_h

// same as ../nrncvode/pool.h but items do not require a clear method.

// create and manage a vector of objects as a memory pool of those objects
// the object must have a void clear() method which takes care of any 
// data the object contains which should be deleted upon free_all.
// clear() is NOT called on free, only on free_all.

// the chain of Pool
// is only for extra items in a pool_ and no other fields are used.
// the pool doubles in size every time a chain Pool is added.
// maxget() tells the most number of pool items used at once.

#define declareStructPool(Pool,T) \
class Pool { \
public: \
   Pool(long count); \
   ~Pool(); \
   T* alloc(); \
   void hpfree(T*); \
   int maxget() { return maxget_;} \
   void free_all(); \
private: \
   void grow(); \
private: \
   T** items_; \
   T* pool_; \
   long pool_size_; \
   long count_; \
   long get_; \
   long put_; \
   long nget_; \
   long maxget_; \
   Pool* chain_; \
}; \
 \

#define implementStructPool(Pool,T) \
Pool::Pool(long count) { \
   count_ = count; \
   pool_ = new T[count_]; \
   pool_size_ = count; \
   items_ = new T*[count_]; \
   for (long i = 0; i < count_; ++i) items_[i] = pool_ + i; \
   get_ = 0; \
   put_ = 0; \
   nget_ = 0; \
   maxget_ = 0; \
   chain_ = 0; \
} \
 \
void Pool::grow() { \
   assert(get_ == put_); \
   Pool* p = new Pool(count_); \
   p->chain_ = chain_; \
   chain_ = p; \
   long newcnt = 2*count_; \
   T** itms = new T*[newcnt]; \
   long i, j; \
   put_ += count_; \
   for (i = 0; i < get_; ++i) { \
      itms[i] = items_[i]; \
   } \
   for (i = get_, j = 0; j < count_; ++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; \
} \
 \
Pool::~Pool() { \
   if (chain_) { \
      delete chain_; \
   } \
   delete [] pool_; \
   if (items_) { \
      delete [] items_; \
   } \
} \
 \
T* Pool::alloc() { \
   if (nget_ >= count_) { grow(); } \
   T* item = items_[get_]; \
   get_ = (get_+1)%count_; \
   ++nget_; \
   if (nget_ > maxget_) { maxget_ = nget_; } \
   return item; \
} \
 \
void Pool::hpfree(T* item) { \
   assert(nget_ > 0); \
   items_[put_] = item; \
   put_ = (put_ + 1)%count_; \
   --nget_; \
} \
\
void Pool::free_all() { \
   Pool* 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; \
      } \
   } \
   assert(put_ == count_); \
   put_ = 0; \
} \
\

#endif