rom/exec/createpool.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Create a memory pool.
   6     Lang: english
   7 */
   8 #include "exec_intern.h"
   9 #include <aros/libcall.h>
  10 #include <clib/alib_protos.h>
  11 #include "memory.h"
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <exec/memory.h>
  17 #include <proto/exec.h>
  18
  19         AROS_LH3(APTR, CreatePool,
  20
  21 /*  SYNOPSIS */
  22         AROS_LHA(ULONG, requirements, D0),
  23         AROS_LHA(ULONG, puddleSize,   D1),
  24         AROS_LHA(ULONG, threshSize,   D2),
  25
  26 /*  LOCATION */
  27         struct ExecBase *, SysBase, 116, Exec)
  28
  29 /*  FUNCTION
  30         Create a private pool for memory allocations.
  31
  32     INPUTS
  33         requirements - The type of the memory
  34         puddleSize   - The number of bytes that the pool expands
  35                        if it is too small.
  36         threshSize   - Allocations beyond the threshSize are given
  37                        directly to the system. threshSize must be
  38                        smaller than the puddleSize.
  39
  40     RESULT
  41         A handle for the memory pool or NULL if the pool couldn't
  42         be created
  43
  44     NOTES
  45
  46     EXAMPLE
  47         \* Get the handle to a private memory pool *\
  48         po=CreatePool(MEMF_ANY,16384,8192);
  49         if(po!=NULL)
  50         {
  51             \* Use the pool *\
  52             UBYTE *mem1,*mem2;
  53             mem1=AllocPooled(po,1000);
  54             mem2=AllocPooled(po,2000);
  55             \* Do something with the memory... *\
  56
  57             \* Free everything at once *\
  58             DeletePool(po);
  59         }
  60
  61     BUGS
  62
  63     SEE ALSO
  64         DeletePool(), AllocPooled(), FreePooled()
  65
  66     INTERNALS
  67
  68 ******************************************************************************/
  69 {
  70     AROS_LIBFUNC_INIT
  71
  72     struct ProtectedPool *pool = NULL;
  73
  74     /* puddleSize must not be smaller than threshSize */
  75     if(puddleSize >= threshSize)
  76     {
  77         LONG poolstruct_size;
  78
  79         /* Round puddleSize up to be a multiple of MEMCHUNK_TOTAL. */
  80         puddleSize = (puddleSize + MEMCHUNK_TOTAL - 1) & ~(MEMCHUNK_TOTAL - 1);
  81
  82         /*
  83             Allocate memory for the Pool structure using the same requirements
  84             as for the whole pool (to make it shareable, residentable or
  85             whatever is needed).
  86         */
  87
  88         poolstruct_size = (requirements & MEMF_SEM_PROTECTED) ? sizeof(struct ProtectedPool) :
  89                                                                 sizeof(struct Pool);
  90
  91         pool=(struct ProtectedPool *)AllocMem(poolstruct_size, requirements & ~MEMF_SEM_PROTECTED);
  92         if(pool != NULL)
  93         {
  94             /* Clear the lists */
  95             NEWLIST((struct List *)&pool->pool.PuddleList);
  96             NEWLIST((struct List *)&pool->pool.BlockList );
  97
  98             /* Set the rest */
  99             pool->pool.Requirements = requirements;
 100             pool->pool.PuddleSize   = puddleSize;
 101             pool->pool.ThreshSize   = threshSize;
 102
 103             if (requirements & MEMF_SEM_PROTECTED)
 104             {
 105                 InitSemaphore(&pool->sem);
 106             }
 107         }
 108
 109     } /* if(puddleSize >= threshSize) */
 110
 111     return pool;
 112
 113     AROS_LIBFUNC_EXIT
 114
 115 } /* CreatePool */