heap: Add _Heap_Greedy_allocate_all_except_largest

Add rtems_workspace_greedy_allocate_all_except_largest() and
rtems_heap_greedy_allocate_all_except_largest().

6 files changed, 92 insertions, 5 deletions

diff --git a/cpukit/libcsupport/include/rtems/malloc.h b/cpukit/libcsupport/include/rtems/malloc.h
index c428bcffb2..25a2e4ea50 100644
--- a/cpukit/libcsupport/include/rtems/malloc.h
+++ b/cpukit/libcsupport/include/rtems/malloc.h
@@ -224,7 +224,7 @@ rtems_status_code rtems_heap_extend(
 /**
  * @brief Greedy allocate that empties the heap.
  *
- * Afterward the heap has at most @a block_count allocatable blocks of sizes
+ * Afterwards the heap has at most @a block_count allocatable blocks of sizes
  * specified by @a block_sizes.  The @a block_sizes must point to an array with
  * @a block_count members.  All other blocks are used.
  *
@@ -236,10 +236,24 @@ void *rtems_heap_greedy_allocate(
 );
 
 /**
+ * @brief Greedy allocate all blocks except the largest free block.
+ *
+ * Afterwards the heap has at most one allocatable block.  This block is the
+ * largest free block if it exists.  The allocatable size of this block is
+ * stored in @a allocatable_size.  All other blocks are used.
+ *
+ * @see rtems_heap_greedy_free().
+ */
+void *rtems_heap_greedy_allocate_all_except_largest(
+  uintptr_t *allocatable_size
+);
+
+/**
  * @brief Frees space of a greedy allocation.
  *
  * The @a opaque argument must be the return value of
- * rtems_heap_greedy_allocate().
+ * rtems_heap_greedy_allocate() or
+ * rtems_heap_greedy_allocate_all_except_largest().
  */
 void rtems_heap_greedy_free( void *opaque );
 
diff --git a/cpukit/libcsupport/src/rtems_heap_greedy.c b/cpukit/libcsupport/src/rtems_heap_greedy.c
index a63ff913cd..19ab28b047 100644
--- a/cpukit/libcsupport/src/rtems_heap_greedy.c
+++ b/cpukit/libcsupport/src/rtems_heap_greedy.c
@@ -39,6 +39,22 @@ void *rtems_heap_greedy_allocate(
   return opaque;
 }
 
+void *rtems_heap_greedy_allocate_all_except_largest(
+  uintptr_t *allocatable_size
+)
+{
+  void *opaque;
+
+  _RTEMS_Lock_allocator();
+  opaque = _Heap_Greedy_allocate_all_except_largest(
+    RTEMS_Malloc_Heap,
+    allocatable_size
+  );
+  _RTEMS_Unlock_allocator();
+
+  return opaque;
+}
+
 void rtems_heap_greedy_free( void *opaque )
 {
   _RTEMS_Lock_allocator();
diff --git a/cpukit/rtems/include/rtems/rtems/support.h b/cpukit/rtems/include/rtems/rtems/support.h
index 1f3cd3da76..335b8c02fa 100644
--- a/cpukit/rtems/include/rtems/rtems/support.h
+++ b/cpukit/rtems/include/rtems/rtems/support.h
@@ -99,7 +99,7 @@ bool rtems_workspace_free(
 /**
  * @brief Greedy allocate that empties the workspace.
  *
- * Afterward the heap has at most @a block_count allocateable blocks of sizes
+ * Afterwards the heap has at most @a block_count allocatable blocks of sizes
  * specified by @a block_sizes.  The @a block_sizes must point to an array with
  * @a block_count members.  All other blocks are used.
  *
@@ -111,10 +111,24 @@ void *rtems_workspace_greedy_allocate(
 );
 
 /**
+ * @brief Greedy allocate all blocks except the largest free block.
+ *
+ * Afterwards the heap has at most one allocatable block.  This block is the
+ * largest free block if it exists.  The allocatable size of this block is
+ * stored in @a allocatable_size.  All other blocks are used.
+ *
+ * @see rtems_workspace_greedy_free().
+ */
+void *rtems_workspace_greedy_allocate_all_except_largest(
+  uintptr_t *allocatable_size
+);
+
+/**
  * @brief Frees space of a greedy allocation.
  *
  * The @a opaque argument must be the return value of
- * rtems_workspace_greedy_allocate().
+ * rtems_workspace_greedy_allocate() or
+ * rtems_workspace_greedy_allocate_all_except_largest().
  */
 void rtems_workspace_greedy_free( void *opaque );
 
diff --git a/cpukit/rtems/src/workspacegreedy.c b/cpukit/rtems/src/workspacegreedy.c
index 8e43370336..4f46e7d919 100644
--- a/cpukit/rtems/src/workspacegreedy.c
+++ b/cpukit/rtems/src/workspacegreedy.c
@@ -40,6 +40,22 @@ void *rtems_workspace_greedy_allocate(
   return opaque;
 }
 
+void *rtems_workspace_greedy_allocate_all_except_largest(
+  uintptr_t *allocatable_size
+)
+{
+  void *opaque;
+
+  _Thread_Disable_dispatch();
+  opaque = _Heap_Greedy_allocate_all_except_largest(
+    &_Workspace_Area,
+    allocatable_size
+  );
+  _Thread_Enable_dispatch();
+
+  return opaque;
+}
+
 void rtems_workspace_greedy_free( void *opaque )
 {
   _Thread_Disable_dispatch();
diff --git a/cpukit/score/include/rtems/score/heap.h b/cpukit/score/include/rtems/score/heap.h
index 2937490896..bea9f3ec25 100644
--- a/cpukit/score/include/rtems/score/heap.h
+++ b/cpukit/score/include/rtems/score/heap.h
@@ -595,7 +595,7 @@ void _Heap_Iterate(
 /**
  * @brief Greedy allocate that empties the heap.
  *
- * Afterward the heap has at most @a block_count allocateable blocks of sizes
+ * Afterwards the heap has at most @a block_count allocatable blocks of sizes
  * specified by @a block_sizes.  The @a block_sizes must point to an array with
  * @a block_count members.  All other blocks are used.
  *
@@ -608,6 +608,20 @@ Heap_Block *_Heap_Greedy_allocate(
 );
 
 /**
+ * @brief Greedy allocate all blocks except the largest free block.
+ *
+ * Afterwards the heap has at most one allocatable block.  This block is the
+ * largest free block if it exists.  The allocatable size of this block is
+ * stored in @a allocatable_size.  All other blocks are used.
+ *
+ * @see _Heap_Greedy_free().
+ */
+Heap_Block *_Heap_Greedy_allocate_all_except_largest(
+  Heap_Control *heap,
+  uintptr_t *allocatable_size
+);
+
+/**
  * @brief Frees blocks of a greedy allocation.
  *
  * The @a blocks must be the return value of _Heap_Greedy_allocate().
diff --git a/cpukit/score/src/heapgreedy.c b/cpukit/score/src/heapgreedy.c
index 23eb4cdd3a..b5c61a4e64 100644
--- a/cpukit/score/src/heapgreedy.c
+++ b/cpukit/score/src/heapgreedy.c
@@ -75,6 +75,19 @@ Heap_Block *_Heap_Greedy_allocate(
   return blocks;
 }
 
+Heap_Block *_Heap_Greedy_allocate_all_except_largest(
+  Heap_Control *heap,
+  uintptr_t *allocatable_size
+)
+{
+  Heap_Information info;
+
+  _Heap_Get_free_information( heap, &info );
+  *allocatable_size = info.largest - HEAP_BLOCK_HEADER_SIZE + HEAP_ALLOC_BONUS;
+
+  return _Heap_Greedy_allocate( heap, allocatable_size, 1 );
+}
+
 void _Heap_Greedy_free(
   Heap_Control *heap,
   Heap_Block *blocks