HolderType borrowObject()
{
#ifdef MAPNIK_THREADSAFE
mutex::scoped_lock lock(mutex_);
#endif
typename ContType::iterator itr=unusedPool_.begin();
if (itr!=unusedPool_.end())
{
#ifdef MAPNIK_DEBUG
std::clog<<"borrow "<<(*itr).get()<<"\n";
#endif
usedPool_.push_back(*itr);
itr=unusedPool_.erase(itr);
return usedPool_[usedPool_.size()-1];
}
else if (unusedPool_.size() < maxSize_)
{
HolderType conn(creator_());
if (conn->isOK())
{
usedPool_.push_back(conn);
#ifdef MAPNIK_DEBUG
std::clog << "create << " << conn.get() << "\n";
#endif
return conn;
}
}
return HolderType();
}
HolderType borrowObject()
{
#ifdef MAPNIK_THREADSAFE
mapnik::scoped_lock lock(mutex_);
#endif
typename ContType::iterator itr=pool_.begin();
while ( itr!=pool_.end())
{
if (!itr->unique())
{
++itr;
}
else if ((*itr)->isOK())
{
return *itr;
}
else
{
itr=pool_.erase(itr);
}
}
// all connection have been taken, check if we allowed to grow pool
if (pool_.size() < maxSize_)
{
HolderType conn(creator_());
if (conn->isOK())
{
pool_.push_back(conn);
return conn;
}
}
return HolderType();
}
Pool(const Creator<T>& creator,unsigned initialSize=1, unsigned maxSize=10)
:creator_(creator),
initialSize_(initialSize),
maxSize_(maxSize)
{
for (unsigned i=0; i < initialSize_; ++i)
{
HolderType conn(creator_());
if (conn->isOK())
unusedPool_.push_back(conn);
}
}
void returnObject(HolderType obj)
{
#ifdef MAPNIK_THREADSAFE
mutex::scoped_lock lock(mutex_);
#endif
typename ContType::iterator itr=usedPool_.begin();
while (itr != usedPool_.end())
{
if (obj.get()==(*itr).get())
{
#ifdef MAPNIK_DEBUG
std::clog<<"return "<<(*itr).get()<<"\n";
#endif
unusedPool_.push_back(*itr);
usedPool_.erase(itr);
return;
}
++itr;
}
}
void set_initial_size(unsigned size)
{
#ifdef MAPNIK_THREADSAFE
mapnik::scoped_lock lock(mutex_);
#endif
if (size > initialSize_)
{
initialSize_ = size;
unsigned total_size = pool_.size();
// ensure we don't have ghost obj's in the pool.
if (total_size < initialSize_)
{
unsigned grow_size = initialSize_ - total_size ;
for (unsigned i=0; i < grow_size; ++i)
{
HolderType conn(creator_());
if (conn->isOK())
pool_.push_back(conn);
}
}
}
}