Renamed mem_realloc() to mem_trim() to prevent confusion with realloc()

CHANGELOG

@@ -131,6 +131,10 @@ HISTORY
 
   ++ Bugfixes:
 
+  2010-02-19: Simon Goldschmidt
+  * mem.c/.h, pbuf.c: Renamed mem_realloc() to mem_trim() to prevent
+    confusion with realloc()
+
   2010-02-15: Simon Goldschmidt/Stephane Lesage
   * netif.c/.h: Link status does not depend on LWIP_NETIF_LINK_CALLBACK
     (fixes bug #28899)

src/core/mem.c

@@ -224,7 +224,7 @@ static volatile u8_t mem_free_count;
  * one empty struct mem pointing to another empty struct mem.
  *
  * @param mem this points to a struct mem which just has been freed
- * @internal this function is only called by mem_free() and mem_realloc()
+ * @internal this function is only called by mem_free() and mem_trim()
  *
  * This assumes access to the heap is protected by the calling function
  * already.
@@ -353,9 +353,7 @@ mem_free(void *rmem)
 }
 
 /**
- * In contrast to its name, mem_realloc can only shrink memory, not expand it.
- * Since the only use (for now) is in pbuf_realloc (which also can only shrink),
- * this shouldn't be a problem!
+ * Shrink memory returned by mem_malloc().
  *
  * @param rmem pointer to memory allocated by mem_malloc the is to be shrinked
  * @param newsize required size after shrinking (needs to be smaller than or
@@ -365,7 +363,7 @@ mem_free(void *rmem)
  *         or freed!
  */
 void *
-mem_realloc(void *rmem, mem_size_t newsize)
+mem_trim(void *rmem, mem_size_t newsize)
 {
   mem_size_t size;
   mem_size_t ptr, ptr2;
@@ -386,12 +384,12 @@ mem_realloc(void *rmem, mem_size_t newsize)
     return NULL;
   }
 
-  LWIP_ASSERT("mem_realloc: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
+  LWIP_ASSERT("mem_trim: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
    (u8_t *)rmem < (u8_t *)ram_end);
 
   if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
     SYS_ARCH_DECL_PROTECT(lev);
-    LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_realloc: illegal memory\n"));
+    LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_trim: illegal memory\n"));
     /* protect mem stats from concurrent access */
     SYS_ARCH_PROTECT(lev);
     MEM_STATS_INC(illegal);
@@ -404,7 +402,7 @@ mem_realloc(void *rmem, mem_size_t newsize)
   ptr = (mem_size_t)((u8_t *)mem - ram);
 
   size = mem->next - ptr - SIZEOF_STRUCT_MEM;
-  LWIP_ASSERT("mem_realloc can only shrink memory", newsize <= size);
+  LWIP_ASSERT("mem_trim can only shrink memory", newsize <= size);
   if (newsize > size) {
     /* not supported */
     return NULL;

src/core/pbuf.c

@@ -383,8 +383,8 @@ pbuf_realloc(struct pbuf *p, u16_t new_len)
   /* (other types merely adjust their length fields */
   if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
     /* reallocate and adjust the length of the pbuf that will be split */
-    q = (struct pbuf *)mem_realloc(q, (u16_t)((u8_t *)q->payload - (u8_t *)q) + rem_len);
-    LWIP_ASSERT("mem_realloc give q == NULL", q != NULL);
+    q = (struct pbuf *)mem_trim(q, (u16_t)((u8_t *)q->payload - (u8_t *)q) + rem_len);
+    LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
   }
   /* adjust length fields for new last pbuf */
   q->len = rem_len;

src/include/lwip/mem.h

@@ -58,10 +58,10 @@ typedef size_t mem_size_t;
 #ifndef mem_calloc
 #define mem_calloc calloc
 #endif
-/* ATTENTION: using realloc is currently not supported since the return value
-   is ignored, so don't define mem_realloc() to realloc()! */
-#ifndef mem_realloc
-#define mem_realloc(mem, size) (mem)
+/* Since there is no C library allocation function to shrink memory without
+   moving it, define this to nothing. */
+#ifndef mem_trim
+#define mem_trim(mem, size) (mem)
 #endif
 #else /* MEM_LIBC_MALLOC */
 
@@ -77,13 +77,13 @@ typedef u16_t mem_size_t;
 #if MEM_USE_POOLS
 /** mem_init is not used when using pools instead of a heap */
 #define mem_init()
-/** mem_realloc is not used when using pools instead of a heap:
+/** mem_trim is not used when using pools instead of a heap:
     we can't free part of a pool element and don't want to copy the rest */
-#define mem_realloc(mem, size) (mem)
+#define mem_trim(mem, size) (mem)
 #else /* MEM_USE_POOLS */
 /* lwIP alternative malloc */
 void  mem_init(void);
-void *mem_realloc(void *mem, mem_size_t size);
+void *mem_trim(void *mem, mem_size_t size);
 #endif /* MEM_USE_POOLS */
 void *mem_malloc(mem_size_t size);
 void *mem_calloc(mem_size_t count, mem_size_t size);

test/unit/core/test_mem.c

@@ -25,7 +25,7 @@ mem_teardown(void)
 
 /* Test functions */
 
-/** Call mem_malloc, mem_free and mem_realloc and check stats */
+/** Call mem_malloc, mem_free and mem_trim and check stats */
 START_TEST(test_mem_one)
 {
 #define SIZE1   16
@@ -51,7 +51,7 @@ START_TEST(test_mem_one)
   fail_unless(lwip_stats.mem.used >= SIZE2 + s1);
   s2 = lwip_stats.mem.used;
 
-  mem_realloc(p1, SIZE1_2);
+  mem_trim(p1, SIZE1_2);
 
   mem_free(p2);
   fail_unless(lwip_stats.mem.used <= s2 - SIZE2);