1 files changed, 105 insertions, 0 deletions
diff --git a/c/src/exec/score/src/heapfree.c b/c/src/exec/score/src/heapfree.c
new file mode 100644
index 0000000000..f4f1075f35
--- /dev/null
+++ b/c/src/exec/score/src/heapfree.c
@@ -0,0 +1,105 @@
+/*
+ *  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_Free
+ *
+ *  This kernel routine returns the memory designated by the
+ *  given heap and given starting address to the memory pool.
+ *
+ *  Input parameters:
+ *    the_heap         - pointer to heap header
+ *    starting_address - starting address of the memory block to free.
+ *
+ *  Output parameters:
+ *    TRUE  - if starting_address is valid heap address
+ *    FALSE - if starting_address is invalid heap address
+ */
+
+boolean _Heap_Free(
+  Heap_Control        *the_heap,
+  void                *starting_address
+)
+{
+  Heap_Block        *the_block;
+  Heap_Block        *next_block;
+  Heap_Block        *new_next_block;
+  Heap_Block        *previous_block;
+  Heap_Block        *temporary_block;
+  unsigned32         the_size;
+
+  the_block = _Heap_User_block_at( starting_address );
+
+  if ( !_Heap_Is_block_in( the_heap, the_block ) ||
+        _Heap_Is_block_free( the_block ) ) {
+      return( FALSE );
+  }
+
+  the_size   = _Heap_Block_size( the_block );
+  next_block = _Heap_Block_at( the_block, the_size );
+
+  if ( !_Heap_Is_block_in( the_heap, next_block ) ||
+       (the_block->front_flag != next_block->back_flag) ) {
+      return( FALSE );
+  }
+
+  if ( _Heap_Is_previous_block_free( the_block ) ) {
+    previous_block = _Heap_Previous_block( the_block );
+
+    if ( !_Heap_Is_block_in( the_heap, previous_block ) ) {
+        return( FALSE );
+    }
+
+    if ( _Heap_Is_block_free( next_block ) ) {      /* coalesce both */
+      previous_block->front_flag += next_block->front_flag + the_size;
+      temporary_block             = _Heap_Next_block( previous_block );
+      temporary_block->back_flag  = previous_block->front_flag;
+      next_block->next->previous  = next_block->previous;
+      next_block->previous->next  = next_block->next;
+    }
+    else {                     /* coalesce prev */
+      previous_block->front_flag =
+      next_block->back_flag      = previous_block->front_flag + the_size;
+    }
+  }
+  else if ( _Heap_Is_block_free( next_block ) ) { /* coalesce next */
+    the_block->front_flag     = the_size + next_block->front_flag;
+    new_next_block            = _Heap_Next_block( the_block );
+    new_next_block->back_flag = the_block->front_flag;
+    the_block->next           = next_block->next;
+    the_block->previous       = next_block->previous;
+    next_block->previous->next = the_block;
+    next_block->next->previous = the_block;
+
+    if (the_heap->first == next_block)
+        the_heap->first = the_block;
+  }
+  else {                          /* no coalesce */
+    next_block->back_flag     =
+    the_block->front_flag     = the_size;
+    the_block->previous       = _Heap_Head( the_heap );
+    the_block->next           = the_heap->first;
+    the_heap->first           = the_block;
+    the_block->next->previous = the_block;
+  }
+
+  return( TRUE );
+}
+