mm/mm_heap: add mm_delaylist to mm_heap_s struct

Change-Id: I2ffaec5557bf2dd2021baa6cda84bb5318425caa
Signed-off-by: ligd <liguiding@fishsemi.com>

include/nuttx/mm/mm.h

@@ -224,6 +224,13 @@ struct mm_freenode_s
   FAR struct mm_freenode_s *blink;
 };
 
+#ifdef __KERNEL__
+struct mm_delaynode_s
+{
+  struct mm_delaynode_s *flink;
+};
+#endif
+
 /* What is the size of the freenode? */
 
 #define MM_PTR_SIZE sizeof(FAR struct mm_freenode_s *)
@@ -263,6 +270,12 @@ struct mm_heap_s
    */
 
   struct mm_freenode_s mm_nodelist[MM_NNODES];
+
+#ifdef __KERNEL__
+  /* Free delay list, for some situation can't do free immdiately */
+
+  struct mm_delaynode_s mm_delaylist;
+#endif
 };
 
 /****************************************************************************

mm/mm_heap/mm_free.c

@@ -42,8 +42,31 @@
 #include <assert.h>
 #include <debug.h>
 
+#include <nuttx/arch.h>
+#include <nuttx/irq.h>
 #include <nuttx/mm/mm.h>
 
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+#ifdef __KERNEL__
+static void mm_add_delaylist(FAR struct mm_heap_s *heap, FAR void *mem)
+{
+  FAR struct mm_delaynode_s *new = mem;
+  irqstate_t flags;
+
+  /* Delay the deallocation until a more appropriate time. */
+
+  flags = enter_critical_section();
+
+  new->flink = heap->mm_delaylist.flink;
+  heap->mm_delaylist.flink = new;
+
+  leave_critical_section(flags);
+}
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -72,11 +95,37 @@ void mm_free(FAR struct mm_heap_s *heap, FAR void *mem)
       return;
     }
 
-  /* We need to hold the MM semaphore while we muck with the
-   * nodelist.
-   */
+#ifdef __KERNEL__
+  /* Check current environment */
+
+  if (up_interrupt_context())
+    {
+      /* We are in ISR, add to mm_delaylist */
+
+      mm_add_delaylist(heap, mem);
+      return;
+    }
+  else if (mm_trysemaphore(heap) == 0)
+    {
+      /* Got the sem, do free immediately */
+    }
+  else if (sched_idletask())
+    {
+      /* We are in IDLE task & can't get sem, add to mm_delaylist */
+
+      mm_add_delaylist(heap, mem);
+      return;
+    }
+  else
+#endif
+    {
+      /* We need to hold the MM semaphore while we muck with the
+       * nodelist.
+       */
+
+      mm_takesemaphore(heap);
+    }
 
-  mm_takesemaphore(heap);
   DEBUGASSERT(mm_heapmember(heap, mem));
 
   /* Map the memory chunk into a free node */

mm/mm_heap/mm_initialize.c

@@ -175,6 +175,12 @@ void mm_initialize(FAR struct mm_heap_s *heap, FAR void *heapstart,
   heap->mm_nregions = 0;
 #endif
 
+#ifdef __KERNEL__
+  /* Initialize mm_delaylist */
+
+  heap->mm_delaylist.flink = NULL;
+#endif
+
   /* Initialize the node array */
 
   memset(heap->mm_nodelist, 0, sizeof(struct mm_freenode_s) * MM_NNODES);

mm/mm_heap/mm_malloc.c

@@ -44,6 +44,7 @@
 #include <debug.h>
 #include <string.h>
 
+#include <nuttx/arch.h>
 #include <nuttx/mm/mm.h>
 
 /****************************************************************************
@@ -54,6 +55,45 @@
 #  define NULL ((void *)0)
 #endif
 
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+#ifdef __KERNEL__
+static void mm_free_delaylist(FAR struct mm_heap_s *heap)
+{
+  FAR struct mm_delaynode_s *tmp;
+  irqstate_t flags;
+
+  /* Move the delay list to local */
+
+  flags = enter_critical_section();
+
+  tmp = heap->mm_delaylist.flink;
+  heap->mm_delaylist.flink = NULL;
+
+  leave_critical_section(flags);
+
+  /* Test if the delayed is empty */
+
+  while (tmp)
+    {
+      FAR void *address;
+
+      /* Get the first delayed deallocation */
+
+      address = tmp;
+      tmp = tmp->flink;
+
+      /* The address should always be non-NULL since that was checked in the
+       * 'while' condition above.
+       */
+
+      mm_free(heap, address);
+    }
+}
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -76,6 +116,12 @@ FAR void *mm_malloc(FAR struct mm_heap_s *heap, size_t size)
   void *ret = NULL;
   int ndx;
 
+#ifdef __KERNEL__
+  /* Firstly, free mm_delaylist */
+
+  mm_free_delaylist(heap);
+#endif
+
   /* Ignore zero-length allocations */
 
   if (size < 1)