diff packages/services/memalloc/common/current/include/mfiximpl.inl @ 115:6ed91473a1cd ecos-sw-2000-08-21

Merge from eCos master repository on 2000-08-21-22:40:54-BST
author jlarmour
date Fri, 25 Aug 2000 17:32:38 +0000
parents
children e0c0827131d1
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+#ifndef CYGONCE_MEMALLOC_MFIXIMPL_INL
+#define CYGONCE_MEMALLOC_MFIXIMPL_INL
+
+//==========================================================================
+//
+//      mfiximpl.inl
+//
+//      Memory pool with fixed block class declarations
+//
+//==========================================================================
+//####COPYRIGHTBEGIN####
+//                                                                          
+// -------------------------------------------                              
+// The contents of this file are subject to the Red Hat eCos Public License 
+// Version 1.1 (the "License"); you may not use this file except in         
+// compliance with the License.  You may obtain a copy of the License at    
+// http://www.redhat.com/                                                   
+//                                                                          
+// Software distributed under the License is distributed on an "AS IS"      
+// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
+// License for the specific language governing rights and limitations under 
+// the License.                                                             
+//                                                                          
+// The Original Code is eCos - Embedded Configurable Operating System,      
+// released September 30, 1998.                                             
+//                                                                          
+// The Initial Developer of the Original Code is Red Hat.                   
+// Portions created by Red Hat are                                          
+// Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             
+// All Rights Reserved.                                                     
+// -------------------------------------------                              
+//                                                                          
+//####COPYRIGHTEND####
+//==========================================================================
+//#####DESCRIPTIONBEGIN####
+//
+// Author(s):    hmt
+// Contributors: jlarmour
+// Date:         2000-06-12
+// Purpose:      Define Mfiximpl class interface
+// Description:  Inline class for constructing a fixed block allocator
+// Usage:        #include <cyg/kernel/mfiximpl.hxx>
+//
+//
+//####DESCRIPTIONEND####
+//
+//==========================================================================
+
+#include <pkgconf/memalloc.h>
+#include <cyg/hal/hal_arch.h>          // HAL_LSBIT_INDEX magic asm code
+#include <cyg/memalloc/mfiximpl.hxx>
+
+// -------------------------------------------------------------------------
+
+inline
+Cyg_Mempool_Fixed_Implementation::Cyg_Mempool_Fixed_Implementation(
+        cyg_uint8 *base,
+        cyg_int32 size,
+        CYG_ADDRWORD alloc_unit )
+{
+    cyg_int32 i;
+    bitmap = (cyg_uint32 *)base;
+    blocksize = alloc_unit;
+
+    CYG_ASSERT( blocksize > 0, "Bad blocksize" );
+    CYG_ASSERT( size > 2, "Bad blocksize" );
+    CYG_ASSERT( blocksize < size, "blocksize, size bad" );
+
+    numblocks = size / blocksize;
+    top = base + size;
+
+    CYG_ASSERT( numblocks >= 2, "numblocks bad" );
+
+    i = (numblocks + 31)/32;        // number of words to map blocks
+    while ( (i * 4 + numblocks * blocksize) > size ) {
+        numblocks --;               // steal one block for admin
+        i = (numblocks + 31)/32;    // number of words to map blocks
+    }
+
+    CYG_ASSERT( 0 < i, "Bad word count for bitmap after fitment" );
+    CYG_ASSERT( 0 < numblocks, "Bad block count after fitment" );
+
+    maptop = i;
+    // this should leave space for the bitmap and maintain alignment
+    mempool = top - (numblocks * blocksize);
+    CYG_ASSERT( base < mempool && mempool < top, "mempool escaped" );
+    CYG_ASSERT( (cyg_uint8 *)(&bitmap[ maptop ]) <= mempool,
+                "mempool overwrites bitmap" );
+    CYG_ASSERT( &mempool[ numblocks * blocksize ] <= top,
+                "mempool overflows top" );
+    freeblocks = numblocks;
+    firstfree = 0;
+
+    // clear out the bitmap; no blocks allocated yet
+    for ( i = 0; i < maptop; i++ )
+        bitmap[ i ] = 0;
+    // apart from the non-existent ones at the top
+    for ( i = ((numblocks-1)&31) + 1; i < 32; i++ )
+        bitmap[ maptop - 1 ] |= ( 1 << i );
+}
+
+// -------------------------------------------------------------------------
+
+inline
+Cyg_Mempool_Fixed_Implementation::~Cyg_Mempool_Fixed_Implementation()
+{
+}
+
+// -------------------------------------------------------------------------
+
+inline cyg_uint8 *
+Cyg_Mempool_Fixed_Implementation::try_alloc( cyg_int32 size )
+{
+    // size parameter is not used
+    CYG_UNUSED_PARAM( cyg_int32, size );
+    if ( 0 >= freeblocks )
+        return NULL;
+    cyg_int32 i = firstfree;
+    cyg_uint8 *p = NULL;
+    do {
+        if ( 0xffffffff != bitmap[ i ] ) {
+            // then there is a free block in this bucket
+            register cyg_uint32 j, k;
+            k = ~bitmap[ i ];       // look for a 1 in complement
+            HAL_LSBIT_INDEX( j, k );
+            CYG_ASSERT( 0 <= j && j <= 31, "Bad bit index" );
+            CYG_ASSERT( 0 == (bitmap[ i ] & (1 << j)), "Found bit not clear" );
+            bitmap[ i ] |= (1 << j); // set it allocated
+            firstfree = i;
+            freeblocks--;
+            CYG_ASSERT( freeblocks >= 0, "allocated too many" );
+            p = &mempool[ ((32 * i) + j) * blocksize ];
+            break;
+        }
+        if ( ++i >= maptop )
+            i = 0;                  // wrap if at top
+    } while ( i != firstfree );     // prevent hang if internal error
+    CYG_ASSERT( NULL != p, "Should have a block here" );
+    CYG_ASSERT( mempool <= p  && p <= top, "alloc mem escaped" );
+    return p;
+}
+    
+// -------------------------------------------------------------------------
+// supposedly resize existing allocation. This is defined in the
+// fixed block allocator purely for API consistency. It will return
+// an error (false) for all values, except for the blocksize
+// returns true on success
+
+inline cyg_uint8 *
+Cyg_Mempool_Fixed_Implementation::resize_alloc( cyg_uint8 *alloc_ptr,
+                                                cyg_int32 newsize,
+                                                cyg_int32 *oldsize )
+{
+    CYG_CHECK_DATA_PTRC( alloc_ptr );
+    if ( NULL != oldsize )
+        CYG_CHECK_DATA_PTRC( oldsize );
+
+    CYG_ASSERT( alloc_ptr >= mempool && alloc_ptr < top,
+                "alloc_ptr outside pool" );
+    
+    if ( NULL != oldsize )
+        *oldsize = blocksize;
+
+    if (newsize == blocksize)
+        return alloc_ptr;
+    else
+        return NULL;
+} // resize_alloc()
+
+
+// -------------------------------------------------------------------------
+
+inline cyg_bool
+Cyg_Mempool_Fixed_Implementation::free( cyg_uint8 *p, cyg_int32 size )
+{
+    // size parameter is not used
+    CYG_UNUSED_PARAM( cyg_int32, size );
+    if ( p < mempool || p >= top )
+        return false;               // address way out of bounds
+    cyg_int32 i = p - mempool;
+    i = i / blocksize;
+    if ( &mempool[ i * blocksize ] != p )
+        return false;               // address not aligned
+    cyg_int32 j = i / 32;
+    CYG_ASSERT( 0 <= j && j < maptop, "map index escaped" );
+    i = i - 32 * j;
+    CYG_ASSERT( 0 <= i && i < 32, "map bit index escaped" );
+    if ( ! ((1 << i) & bitmap[ j ] ) )
+        return false;               // block was not allocated
+    bitmap[ j ] &=~(1 << i);        // clear the bit
+    freeblocks++;                   // count the block
+    CYG_ASSERT( freeblocks <= numblocks, "freeblocks overflow" );
+    return true;
+}
+
+// -------------------------------------------------------------------------
+
+inline void
+Cyg_Mempool_Fixed_Implementation::get_status(
+    cyg_mempool_status_flag_t flags,
+    Cyg_Mempool_Status &status )
+{
+// as quick or quicker to just set it, rather than test flag first
+    status.arenabase = (const cyg_uint8 *)bitmap;
+    if ( 0 != (flags & CYG_MEMPOOL_STAT_ARENASIZE) )
+        status.arenasize = top - (cyg_uint8 *)bitmap;
+    if ( 0 != (flags & CYG_MEMPOOL_STAT_FREEBLOCKS) )
+        status.freeblocks = freeblocks;
+    if ( 0 != (flags & CYG_MEMPOOL_STAT_TOTALALLOCATED) )
+        status.totalallocated = blocksize * numblocks;
+    if ( 0 != (flags & CYG_MEMPOOL_STAT_TOTALFREE) )
+        status.totalfree = blocksize * freeblocks;
+    if ( 0 != (flags & CYG_MEMPOOL_STAT_BLOCKSIZE) )
+        status.blocksize = blocksize;
+    if ( 0 != (flags & CYG_MEMPOOL_STAT_MAXFREE) ) {
+        status.maxfree = freeblocks > 0 ? blocksize : 0;
+    }
+// as quick or quicker to just set it, rather than test flag first
+    status.origbase = (const cyg_uint8 *)bitmap;
+    if ( 0 != (flags & CYG_MEMPOOL_STAT_ORIGSIZE) )
+        status.origsize = top - (cyg_uint8 *)bitmap;
+// quicker to just set it, rather than test flag first
+    status.maxoverhead = 0;
+        
+} // get_status()
+
+// -------------------------------------------------------------------------
+#endif // ifndef CYGONCE_MEMALLOC_MFIXIMPL_INL
+// EOF mfiximpl.inl