rom/exec/allocpooled.c

   1 /*
   2     Copyright © 1995-2009, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Allocate memory in a pool.
   6     Lang: english
   7 */
   8 #include "exec_intern.h"
   9 #include <aros/libcall.h>
  10 #include "memory.h"
  11
  12 #include "exec_debug.h"
  13 #ifndef DEBUG_AllocPooled
  14 #   define DEBUG_AllocPooled 0
  15 #endif
  16 #undef DEBUG
  17 #if DEBUG_AllocPooled
  18 #   define DEBUG 1
  19 #endif
  20 #include <aros/debug.h>
  21 #undef kprintf
  22
  23 /*****************************************************************************
  24
  25     NAME */
  26 #include <exec/memory.h>
  27 #include <proto/exec.h>
  28
  29         AROS_LH2(APTR, AllocPooled,
  30
  31 /*  SYNOPSIS */
  32         AROS_LHA(APTR,  poolHeader, A0),
  33         AROS_LHA(ULONG, memSize,    D0),
  34
  35 /*  LOCATION */
  36         struct ExecBase *, SysBase, 118, Exec)
  37
  38 /*  FUNCTION
  39         Allocate memory out of a private memory pool.
  40
  41     INPUTS
  42         poolHeader - Handle of the memory pool
  43         memSize    - Number of bytes you want to get
  44
  45     RESULT
  46         A pointer to the number of bytes you wanted or NULL if the memory
  47         couldn't be allocated
  48
  49     NOTES
  50
  51     EXAMPLE
  52
  53     BUGS
  54
  55     SEE ALSO
  56         CreatePool(), DeletePool(), FreePooled()
  57
  58     INTERNALS
  59
  60 ******************************************************************************/
  61 {
  62     AROS_LIBFUNC_INIT
  63
  64     struct ProtectedPool *pool = (struct ProtectedPool *)poolHeader;
  65     APTR                 ret = NULL;
  66
  67     D(bug("AllocPooled $%lx memsize $%lx by \"%s\"\n", poolHeader, memSize, SysBase->ThisTask->tc_Node.ln_Name));
  68
  69     if (pool->pool.Requirements & MEMF_SEM_PROTECTED)
  70     {
  71         ObtainSemaphore(&pool->sem);
  72     }
  73
  74     /* If the memSize is bigger than the ThreshSize allocate seperately. */
  75     if(memSize > pool->pool.ThreshSize)
  76     {
  77         struct Block *bl;
  78         ULONG        size;
  79
  80         /* Get enough memory for the memory block including the header. */
  81         size = memSize + BLOCK_TOTAL;
  82         bl = (struct Block *)AllocMem(size, pool->pool.Requirements & ~MEMF_SEM_PROTECTED);
  83
  84         /* No memory left */
  85         if(bl == NULL)
  86             goto done;
  87
  88         /* Initialize the header */
  89         bl->Size = size;
  90
  91         /* Add the block to the BlockList */
  92         AddHead((struct List *)&pool->pool.BlockList,(struct Node *)&bl->Node);
  93
  94         /* Set pointer to allocated memory */
  95         ret = (UBYTE *)bl + BLOCK_TOTAL;
  96     }
  97     else
  98     {
  99         struct MemHeader *mh;
 100
 101         /* Follow the list of MemHeaders */
 102         mh = (struct MemHeader *)pool->pool.PuddleList.mlh_Head;
 103         for(;;)
 104         {
 105             /* Are there no more MemHeaders? */
 106             if(mh->mh_Node.ln_Succ==NULL)
 107             {
 108                 /* Get a new one */
 109                 mh = (struct MemHeader *)
 110                    AllocMem(pool->pool.PuddleSize + MEMHEADER_TOTAL,
 111                             pool->pool.Requirements & ~MEMF_SEM_PROTECTED);
 112
 113                 /* No memory left? */
 114                 if(mh == NULL)
 115                     goto done;
 116
 117                 /* Initialize new MemHeader */
 118                 mh->mh_First            = (struct MemChunk *)((UBYTE *)mh + MEMHEADER_TOTAL);
 119                 mh->mh_First->mc_Next   = NULL;
 120                 mh->mh_First->mc_Bytes  = pool->pool.PuddleSize;
 121                 mh->mh_Lower            = mh->mh_First;
 122                 mh->mh_Upper            = (UBYTE *)mh->mh_First+pool->pool.PuddleSize;
 123                 mh->mh_Free             = pool->pool.PuddleSize;
 124
 125                 /* And add it to the list */
 126                 AddHead((struct List *)&pool->pool.PuddleList, (struct Node *)&mh->mh_Node);
 127                 /* Fall through to get the memory */
 128             }
 129             /* Try to get the memory */
 130             ret = Allocate(mh, memSize);
 131
 132         /* Got it? */
 133         if(ret != NULL)
 134         {
 135             /* If this is not the first MemHeader and it has some free space, move it to the head */
 136             if (mh->mh_Node.ln_Pred != NULL && mh->mh_Free > 32)
 137             {
 138                 Remove(mh);
 139                 AddHead((struct List *)&pool->pool.PuddleList, (struct Node *)&mh->mh_Node);
 140             }
 141
 142             break;
 143         }
 144
 145             /* No. Try next MemHeader */
 146             mh = (struct MemHeader *)mh->mh_Node.ln_Succ;
 147         }
 148         /* Allocate does not clear the memory! */
 149         if(pool->pool.Requirements & MEMF_CLEAR)
 150         {
 151             ULONG *p= (ULONG *)ret;
 152
 153             /* Round up (clearing longs is faster than just bytes) */
 154             memSize = (memSize + sizeof(ULONG) - 1) / sizeof(ULONG);
 155
 156             /* NUL the memory out */
 157             while(memSize--)
 158                 *p++=0;
 159         }
 160     }
 161
 162 done:
 163     if (pool->pool.Requirements & MEMF_SEM_PROTECTED)
 164     {
 165         ReleaseSemaphore(&pool->sem);
 166     }
 167
 168     /* Everything fine */
 169     return ret;
 170
 171     AROS_LIBFUNC_EXIT
 172
 173 } /* AllocPooled */
 174