gdipp_server/dc_pool.cpp

   1 #include "stdafx.h"
   2 #include "dc_pool.h"
   3 #include "gdipp_lib/lock.h"
   4
   5 namespace gdipp
   6 {
   7
   8 dc_pool::~dc_pool()
   9 {
  10         // TODO: change to blockingly wait until _busy.empty() is true
  11         assert(_busy.empty());
  12
  13         BOOL b_ret;
  14
  15         for (std::list<HDC>::const_iterator free_iter = _free.begin(); free_iter != _free.end(); ++free_iter)
  16         {
  17                 b_ret = DeleteDC(*free_iter);
  18                 assert(b_ret);
  19         }
  20 }
  21
  22 HDC dc_pool::claim()
  23 {
  24         // acquire a resource from the pool
  25         // if no resource exists, create one by calling create() of the template class
  26         // otherwise, remove one from the free resource set and add to busy set
  27
  28         lock l(lock::SERVER_DC_POOL);
  29
  30         HDC hdc;
  31
  32         if (_free.empty())
  33         {
  34                 hdc = CreateCompatibleDC(NULL);
  35         }
  36         else
  37         {
  38                 hdc = _free.front();
  39                 _free.pop_front();
  40         }
  41         _busy.insert(hdc);
  42
  43         return hdc;
  44 }
  45
  46 bool dc_pool::free(HDC hdc)
  47 {
  48         // return claimed resource back to the pool
  49
  50         lock l(lock::SERVER_DC_POOL);
  51
  52         std::set<HDC>::const_iterator busy_iter = _busy.find(hdc);
  53         if (busy_iter == _busy.end())
  54                 return false;
  55
  56         _free.push_back(*busy_iter);
  57         _busy.erase(busy_iter);
  58
  59         return true;
  60 }
  61
  62 }