6 files changed, 144 insertions, 2 deletions
diff --git a/cpukit/libcsupport/Makefile.am b/cpukit/libcsupport/Makefile.am
index ec06f901a1..15e55a1e51 100644
--- a/cpukit/libcsupport/Makefile.am
+++ b/cpukit/libcsupport/Makefile.am
@@ -107,7 +107,8 @@ MALLOC_C_FILES = src/malloc_initialize.c src/calloc.c src/malloc.c \
     src/malloc_statistics_helpers.c src/posix_memalign.c \
     src/rtems_memalign.c src/malloc_deferred.c src/malloc_sbrk_helpers.c \
     src/malloc_dirtier.c src/malloc_p.h src/rtems_malloc.c \
-    src/rtems_heap_extend.c
+    src/rtems_heap_extend.c \
+    src/rtems_heap_greedy.c
 
 PASSWORD_GROUP_C_FILES = src/getpwent.c
 
diff --git a/cpukit/libcsupport/include/rtems/malloc.h b/cpukit/libcsupport/include/rtems/malloc.h
index e1dfb08445..a8eb434d3b 100644
--- a/cpukit/libcsupport/include/rtems/malloc.h
+++ b/cpukit/libcsupport/include/rtems/malloc.h
@@ -184,6 +184,24 @@ rtems_status_code rtems_heap_extend(
   uintptr_t area_size
 );
 
+/**
+ * @brief Greedy allocate that empties the heap.
+ *
+ * Afterward the heap has at most @a remaining_free_space free space left in
+ * one free block.  All other blocks are used.
+ *
+ * @see rtems_heap_greedy_free().
+ */
+void *rtems_heap_greedy_allocate( size_t remaining_free_space );
+
+/**
+ * @brief Frees space of a greedy allocation.
+ *
+ * The @a opaque argument must be the return value of
+ * rtems_heap_greedy_allocate().
+ */
+void rtems_heap_greedy_free( void *opaque );
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/cpukit/libcsupport/src/rtems_heap_greedy.c b/cpukit/libcsupport/src/rtems_heap_greedy.c
new file mode 100644
index 0000000000..d363fe4d3b
--- /dev/null
+++ b/cpukit/libcsupport/src/rtems_heap_greedy.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2012 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Obere Lagerstr. 30
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include "malloc_p.h"
+
+void *rtems_heap_greedy_allocate( size_t remaining_free_space )
+{
+  void *opaque;
+
+  _RTEMS_Lock_allocator();
+  opaque = _Heap_Greedy_allocate( RTEMS_Malloc_Heap, remaining_free_space );
+  _RTEMS_Unlock_allocator();
+
+  return opaque;
+}
+
+void rtems_heap_greedy_free( void *opaque )
+{
+  _RTEMS_Lock_allocator();
+  _Heap_Greedy_free( RTEMS_Malloc_Heap, opaque );
+  _RTEMS_Unlock_allocator();
+}
diff --git a/cpukit/score/Makefile.am b/cpukit/score/Makefile.am
index 13c31826b9..597da3e0cc 100644
--- a/cpukit/score/Makefile.am
+++ b/cpukit/score/Makefile.am
@@ -181,7 +181,8 @@ endif
 ## HEAP_C_FILES
 libscore_a_SOURCES += src/heap.c src/heapallocate.c src/heapextend.c \
     src/heapfree.c src/heapsizeofuserarea.c src/heapwalk.c src/heapgetinfo.c \
-    src/heapgetfreeinfo.c src/heapresizeblock.c src/heapiterate.c
+    src/heapgetfreeinfo.c src/heapresizeblock.c src/heapiterate.c \
+    src/heapgreedy.c
 
 ## OBJECT_C_FILES
 libscore_a_SOURCES += src/objectallocate.c src/objectclose.c \
diff --git a/cpukit/score/include/rtems/score/heap.h b/cpukit/score/include/rtems/score/heap.h
index 1996fb80ff..8f508c9874 100644
--- a/cpukit/score/include/rtems/score/heap.h
+++ b/cpukit/score/include/rtems/score/heap.h
@@ -549,6 +549,29 @@ void _Heap_Iterate(
 );
 
 /**
+ * @brief Greedy allocate that empties the heap.
+ *
+ * Afterward the heap has at most @a remaining_free_space free space left in
+ * one free block.  All other blocks are used.
+ *
+ * @see _Heap_Greedy_free().
+ */
+Heap_Block *_Heap_Greedy_allocate(
+  Heap_Control *heap,
+  uintptr_t remaining_free_space
+);
+
+/**
+ * @brief Frees blocks of a greedy allocation.
+ *
+ * The @a blocks must be the return value of _Heap_Greedy_allocate().
+ */
+void _Heap_Greedy_free(
+  Heap_Control *heap,
+  Heap_Block *blocks
+);
+
+/**
  * @brief Returns information about used and free blocks for the heap @a heap
  * in @a info.
  */
diff --git a/cpukit/score/src/heapgreedy.c b/cpukit/score/src/heapgreedy.c
new file mode 100644
index 0000000000..4b38b7858a
--- /dev/null
+++ b/cpukit/score/src/heapgreedy.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2012 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Obere Lagerstr. 30
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/score/heap.h>
+
+Heap_Block *_Heap_Greedy_allocate(
+  Heap_Control *heap,
+  uintptr_t remaining_free_space
+)
+{
+  void *free_space = remaining_free_space > 0 ?
+    _Heap_Allocate( heap, remaining_free_space )
+      : NULL;
+  Heap_Block *const free_list_tail = _Heap_Free_list_tail( heap );
+  Heap_Block *current = _Heap_Free_list_first( heap );
+  Heap_Block *blocks = NULL;
+
+  while ( current != free_list_tail ) {
+    _Heap_Block_allocate(
+      heap,
+      current,
+      _Heap_Alloc_area_of_block( current ),
+      _Heap_Block_size( current ) - HEAP_BLOCK_HEADER_SIZE
+    );
+
+    current->next = blocks;
+    blocks = current;
+    current = _Heap_Free_list_first( heap );
+  }
+
+  _Heap_Free( heap, free_space );
+
+  return blocks;
+}
+
+void _Heap_Greedy_free(
+  Heap_Control *heap,
+  Heap_Block *blocks
+)
+{
+  while ( blocks != NULL ) {
+    Heap_Block *current = blocks;
+
+    blocks = blocks->next;
+    _Heap_Free( heap, (void *) _Heap_Alloc_area_of_block( current ) );
+  }
+}