src/lib/16_pm.h

   1 //\r
   2 //      ID_PM.H\r
   3 //      Header file for Id Engine's Page Manager\r
   4 //\r
   5 \r
   6 //      NOTE! PMPageSize must be an even divisor of EMSPageSize, and >= 1024\r
   7 #define EMSPageSize             16384\r
   8 #define EMSPageSizeSeg  (EMSPageSize >> 4)\r
   9 #define EMSPageSizeKB   (EMSPageSize >> 10)\r
  10 #define EMSFrameCount   4\r
  11 #define PMPageSize              4096\r
  12 #define PMPageSizeSeg   (PMPageSize >> 4)\r
  13 #define PMPageSizeKB    (PMPageSize >> 10)\r
  14 #define PMEMSSubPage    (EMSPageSize / PMPageSize)\r
  15 \r
  16 #define PMMinMainMem    10                      // Min acceptable # of pages from main\r
  17 #define PMMaxMainMem    100                     // Max number of pages in main memory\r
  18 \r
  19 #define PMThrashThreshold       1       // Number of page thrashes before panic mode\r
  20 #define PMUnThrashThreshold     5       // Number of non-thrashing frames before leaving panic mode\r
  21 \r
  22 typedef enum\r
  23                 {\r
  24                         pml_Unlocked,\r
  25                         pml_Locked\r
  26                 } PMLockType;\r
  27 \r
  28 typedef enum\r
  29                 {\r
  30                         pmba_Unused = 0,\r
  31                         pmba_Used = 1,\r
  32                         pmba_Allocated = 2\r
  33                 } PMBlockAttr;\r
  34 \r
  35 typedef struct\r
  36                 {\r
  37                         longword        offset;         // Offset of chunk into file\r
  38                         word            length;         // Length of the chunk\r
  39 \r
  40                         int                     xmsPage;        // If in XMS, (xmsPage * PMPageSize) gives offset into XMS handle\r
  41 \r
  42                         PMLockType      locked;         // If set, this page can't be purged\r
  43                         int                     emsPage;        // If in EMS, logical page/offset into page\r
  44                         int                     mainPage;       // If in Main, index into handle array\r
  45 \r
  46                         longword        lastHit;        // Last frame number of hit\r
  47                 } PageListStruct;\r
  48 \r
  49 typedef struct\r
  50                 {\r
  51                         int                     baseEMSPage;    // Base EMS page for this phys frame\r
  52                         longword        lastHit;                // Last frame number of hit\r
  53                 } EMSListStruct;\r
  54 \r
  55 extern  boolean                 XMSPresent,EMSPresent;\r
  56 extern  word                    XMSPagesAvail,EMSPagesAvail;\r
  57 \r
  58 extern  word                    ChunksInFile,\r
  59                                                 PMSpriteStart,PMSoundStart;\r
  60 extern  PageListStruct  far *PMPages;\r
  61 \r
  62 #define PM_GetSoundPage(v)      PM_GetPage(PMSoundStart + (v))\r
  63 #define PM_GetSpritePage(v)     PM_GetPage(PMSpriteStart + (v))\r
  64 \r
  65 #define PM_LockMainMem()        PM_SetMainMemPurge(0)\r
  66 #define PM_UnlockMainMem()      PM_SetMainMemPurge(3)\r
  67 \r
  68 \r
  69 extern  char    PageFileName[13];\r
  70 \r
  71 \r
  72 extern  void    PM_Startup(void),\r
  73                                 PM_Shutdown(void),\r
  74                                 PM_Reset(void),\r
  75                                 PM_Preload(boolean (*update)(word current,word total)),\r
  76                                 PM_NextFrame(void),\r
  77                                 PM_SetPageLock(int pagenum,PMLockType lock),\r
  78                                 PM_SetMainPurge(int level),\r
  79                                 PM_CheckMainMem(void);\r
  80 extern  memptr  PM_GetPageAddress(int pagenum),\r
  81                                 PM_GetPage(int pagenum);                // Use this one to cache page\r
  82 \r
  83 void PM_SetMainMemPurge(int level);\r