WDL/rpool.h

   1 /*
   2   WDL - rpool.h
   3   Copyright (C) 2006 and later, Cockos Incorporated
   4
   5   This software is provided 'as-is', without any express or implied
   6   warranty.  In no event will the authors be held liable for any damages
   7   arising from the use of this software.
   8
   9   Permission is granted to anyone to use this software for any purpose,
  10   including commercial applications, and to alter it and redistribute it
  11   freely, subject to the following restrictions:
  12
  13   1. The origin of this software must not be misrepresented; you must not
  14      claim that you wrote the original software. If you use this software
  15      in a product, an acknowledgment in the product documentation would be
  16      appreciated but is not required.
  17   2. Altered source versions must be plainly marked as such, and must not be
  18      misrepresented as being the original software.
  19   3. This notice may not be removed or altered from any source distribution.
  20
  21
  22   This file defines a template for a class that stores a list of objects, and allows the caller
  23   to periodically get an object, do something with it, and add it back into the pool.
  24
  25   When the caller does this, it can set ownership of the object, and an expiration for that ownership.
  26
  27
  28   The PTYPE1 and PTYPE2entries for the template are there to store additional information (for use with poollist.h)
  29
  30
  31   This is pretty esoteric. But we use it for some things.
  32
  33 */
  34
  35
  36 #ifndef _WDL_RPOOL_H_
  37 #define _WDL_RPOOL_H_
  38
  39 // resource pool (time based)
  40
  41 #include "ptrlist.h"
  42 #include "mutex.h"
  43
  44 class WDL_ResourcePool_ResInfo // include in class RTYPE as WDL_ResourcePool_ResInfo m_rpoolinfo;
  45 {
  46 public:
  47   WDL_ResourcePool_ResInfo(){ m_owneduntil=0; m_ownerptr=0; next=0; }
  48   ~WDL_ResourcePool_ResInfo() {}
  49
  50   unsigned int m_owneduntil;
  51   void *m_ownerptr;
  52
  53   void *next;
  54 } WDL_FIXALIGN;
  55
  56
  57 template<class RTYPE, class EXTRAINFOTYPE> class WDL_ResourcePool
  58 {
  59   public:
  60     WDL_ResourcePool(char *identstr)
  61     {
  62       WDL_POOLLIST_refcnt=0;
  63       WDL_POOLLIST_identstr=identstr;
  64       m_rlist=NULL;
  65       extraInfo=0;
  66       m_hadres=false;
  67     }
  68     ~WDL_ResourcePool()
  69     {
  70       while (m_rlist)
  71       {
  72         RTYPE *tp=m_rlist;
  73         m_rlist=(RTYPE *)m_rlist->m_rpoolinfo.next;
  74         delete tp;
  75       }
  76       delete extraInfo;
  77     }
  78     void Clear()
  79     {
  80       m_mutex.Enter();
  81       while (m_rlist)
  82       {
  83         RTYPE *tp=m_rlist;
  84         m_rlist=(RTYPE *)m_rlist->m_rpoolinfo.next;
  85         delete tp;
  86       }
  87       m_hadres=false;
  88       m_mutex.Leave();
  89     }
  90     bool HasResources()
  91     {
  92       return m_hadres;
  93     }
  94
  95     void AddResource(RTYPE *item, void *own, unsigned int until)
  96     {
  97       item->m_rpoolinfo.m_ownerptr = own;
  98       item->m_rpoolinfo.m_owneduntil = until;
  99
 100       m_mutex.Enter();
 101       item->m_rpoolinfo.next = m_rlist;
 102       m_rlist = item;
 103       m_hadres=true;
 104       m_mutex.Leave();
 105     }
 106
 107     void ReleaseResources(void *own)
 108     {
 109       m_mutex.Enter();
 110       RTYPE *ent=m_rlist;
 111       while (ent)
 112       {
 113         if (ent->m_rpoolinfo.m_ownerptr == own)
 114         {
 115           ent->m_rpoolinfo.m_ownerptr = 0;
 116           ent->m_rpoolinfo.m_owneduntil=0;
 117         }
 118         ent=(RTYPE *)ent->m_rpoolinfo.next;
 119       }
 120       m_mutex.Leave();
 121     }
 122
 123     RTYPE *GetResource(void *own, unsigned int now)
 124     {
 125       m_mutex.Enter();
 126       RTYPE *ent=m_rlist, *lastent=NULL, *bestent=NULL, *bestlastent=NULL;
 127       bool bestnoown=false;
 128       while (ent)
 129       {
 130         if (ent->m_rpoolinfo.m_ownerptr == own)
 131         {
 132           if (lastent) lastent->m_rpoolinfo.next = ent->m_rpoolinfo.next;
 133           else m_rlist = (RTYPE *)ent->m_rpoolinfo.next;
 134           m_mutex.Leave();
 135           return ent;
 136         }
 137
 138         if (!bestnoown && (!ent->m_rpoolinfo.m_ownerptr || ent->m_rpoolinfo.m_owneduntil < now))
 139         {
 140           bestent=ent;
 141           bestlastent=lastent;
 142           if (!ent->m_rpoolinfo.m_ownerptr || !ent->m_rpoolinfo.m_owneduntil) bestnoown=true;
 143         }
 144         lastent=ent;
 145         ent=(RTYPE *)ent->m_rpoolinfo.next;
 146       }
 147
 148       if (bestent)
 149       {
 150         if (bestlastent) bestlastent->m_rpoolinfo.next = bestent->m_rpoolinfo.next;
 151         else m_rlist = (RTYPE *)bestent->m_rpoolinfo.next;
 152       }
 153
 154       m_mutex.Leave();
 155       return bestent;
 156     }
 157
 158     int WDL_POOLLIST_refcnt;
 159     char *WDL_POOLLIST_identstr;
 160     bool m_hadres;
 161
 162     EXTRAINFOTYPE *extraInfo;
 163
 164     RTYPE *PeekList()
 165     {
 166       return m_rlist;
 167     }
 168     void LockList()
 169     {
 170       m_mutex.Enter();
 171     }
 172     void UnlockList()
 173     {
 174       m_mutex.Leave();
 175     }
 176
 177 private:
 178
 179   WDL_Mutex m_mutex;
 180   RTYPE *m_rlist;
 181
 182 } WDL_FIXALIGN;
 183
 184
 185
 186 #endif