From 93b4e6ef7ea97190a1d542191e78e287a3b540f4 Mon Sep 17 00:00:00 2001
From: Joel Sherrill <joel.sherrill@OARcorp.com>
Date: Tue, 2 Nov 1999 21:05:17 +0000
Subject: Split Heap and Time of Day Handlers.

---
 cpukit/score/src/heapallocate.c | 107 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 cpukit/score/src/heapallocate.c

(limited to 'cpukit/score/src/heapallocate.c')

diff --git a/cpukit/score/src/heapallocate.c b/cpukit/score/src/heapallocate.c
new file mode 100644
index 0000000000..e6e103e6be
--- /dev/null
+++ b/cpukit/score/src/heapallocate.c
@@ -0,0 +1,107 @@
+/*
+ *  Heap Handler
+ *
+ *  COPYRIGHT (c) 1989-1998.
+ *  On-Line Applications Research Corporation (OAR).
+ *  Copyright assigned to U.S. Government, 1994.
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.OARcorp.com/rtems/license.html.
+ *
+ *  $Id$
+ */
+
+
+#include <rtems/system.h>
+#include <rtems/score/sysstate.h>
+#include <rtems/score/heap.h>
+
+/*PAGE
+ *
+ *  _Heap_Allocate
+ *
+ *  This kernel routine allocates the requested size of memory
+ *  from the specified heap.
+ *
+ *  Input parameters:
+ *    the_heap  - pointer to heap header.
+ *    size      - size in bytes of the memory block to allocate.
+ *
+ *  Output parameters:
+ *    returns - starting address of memory block allocated
+ */
+
+void *_Heap_Allocate(
+  Heap_Control        *the_heap,
+  unsigned32           size
+)
+{
+  unsigned32  excess;
+  unsigned32  the_size;
+  Heap_Block *the_block;
+  Heap_Block *next_block;
+  Heap_Block *temporary_block;
+  void       *ptr;
+  unsigned32  offset;
+  
+  excess   = size % the_heap->page_size;
+  the_size = size + the_heap->page_size + HEAP_BLOCK_USED_OVERHEAD;
+  
+  if ( excess )
+    the_size += the_heap->page_size - excess;
+
+  if ( the_size < sizeof( Heap_Block ) )
+    the_size = sizeof( Heap_Block );
+
+  for ( the_block = the_heap->first;
+        ;
+        the_block = the_block->next ) {
+    if ( the_block == _Heap_Tail( the_heap ) )
+      return( NULL );
+    if ( the_block->front_flag >= the_size )
+      break;
+  }
+
+  if ( (the_block->front_flag - the_size) >
+       (the_heap->page_size + HEAP_BLOCK_USED_OVERHEAD) ) {
+    the_block->front_flag -= the_size;
+    next_block             = _Heap_Next_block( the_block );
+    next_block->back_flag  = the_block->front_flag;
+
+    temporary_block            = _Heap_Block_at( next_block, the_size );
+    temporary_block->back_flag =
+    next_block->front_flag     = _Heap_Build_flag( the_size,
+                                    HEAP_BLOCK_USED );
+    ptr = _Heap_Start_of_user_area( next_block );
+  } else {
+    next_block                = _Heap_Next_block( the_block );
+    next_block->back_flag     = _Heap_Build_flag( the_block->front_flag,
+                                   HEAP_BLOCK_USED );
+    the_block->front_flag     = next_block->back_flag;
+    the_block->next->previous = the_block->previous;
+    the_block->previous->next = the_block->next;
+    ptr = _Heap_Start_of_user_area( the_block );
+  }
+  
+  /*
+   * round ptr up to a multiple of page size
+   * Have to save the bump amount in the buffer so that free can figure it out
+   */
+  
+  offset = the_heap->page_size - (((unsigned32) ptr) & (the_heap->page_size - 1));
+  ptr = _Addresses_Add_offset( ptr, offset );
+  *(((unsigned32 *) ptr) - 1) = offset;
+
+#ifdef RTEMS_DEBUG
+  {
+      unsigned32 ptr_u32;
+      ptr_u32 = (unsigned32) ptr;
+      if (ptr_u32 & (the_heap->page_size - 1))
+          abort();
+  }
+#endif
+
+  return ptr;
+}
+
-- 
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