Changed the pbuf_free/mem_free callback functions a little: created extra functions for that

CHANGELOG

@@ -25,9 +25,8 @@ HISTORY
   2008-03-27 Simon Goldschmidt
   * mem.c, tcpip.c, tcpip.h, opt.h: fixed bug #21433 (Calling mem_free/pbuf_free
     from interrupt context isn't safe): set LWIP_USE_HEAP_FROM_INTERRUPT to 1
-    in lwipopts.h or use tcpip_callback_nonblocking(pbuf_free_int, p)/
-    tcpip_callback_nonblocking(mem_free, m) to free pbufs or heap memory from
-    interrupt context
+    in lwipopts.h or use pbuf_free_callback(p)/mem_free_callback(m) to free pbufs
+    or heap memory from interrupt context
 
   2008-03-26 Simon Goldschmidt
   * tcp_in.c, tcp.c: fixed bug #22249: division by zero could occur if a remote

src/api/tcpip.c

@@ -518,17 +518,42 @@ tcpip_init(void (* initfunc)(void *), void *arg)
   sys_thread_new(TCPIP_THREAD_NAME, tcpip_thread, NULL, TCPIP_THREAD_STACKSIZE, TCPIP_THREAD_PRIO);
 }
 
-
 /**
- * A simple wrapper function that allows you to free a pbuf using one of the
- * tcpip_callback functions.
+ * Simple callback function used with tcpip_callback to free a pbuf
+ * (pbuf_free has a wrong signature for tcpip_callback)
  *
  * @param p The pbuf (chain) to be dereferenced.
  */
-void
-pbuf_free_int(struct pbuf *p)
+static void
+pub_free_int(void *p)
 {
-  pbuf_free(p);
+  struct pbuf *q = p;
+  pbuf_free(q);
+}
+
+/**
+ * A simple wrapper function that allows you to free a pbuf from interrupt context.
+ *
+ * @param p The pbuf (chain) to be dereferenced.
+ * @return ERR_OK if callback could be enqueued, an err_t if not
+ */
+err_t
+pbuf_free_callback(struct pbuf *p)
+{
+  return tcpip_callback_with_block(pub_free_int, p, 0);
+}
+
+/**
+ * A simple wrapper function that allows you to free heap memory from
+ * interrupt context.
+ *
+ * @param m the heap memory to free
+ * @return ERR_OK if callback could be enqueued, an err_t if not
+ */
+err_t
+mem_free_callback(void *m)
+{
+  return tcpip_callback_with_block(mem_free, m, 0);
 }
 
 #endif /* !NO_SYS */

src/include/lwip/opt.h

@@ -166,8 +166,8 @@
  * *** USE THIS WITH CARE: Setting this to 1 can disable interrupts for a long time! ***
  *
  * If you don't want that, call
- * - tcpip_callback_nonblocking(pbuf_free_int, p);
- * - tcpip_callback_nonblocking(mem_free, m);
+ * - pbuf_free_callback(p);
+ * - mem_free_callback(m);
  */
 #ifndef LWIP_USE_HEAP_FROM_INTERRUPT
 #define LWIP_USE_HEAP_FROM_INTERRUPT    0

src/include/lwip/tcpip.h

@@ -84,9 +84,9 @@ err_t tcpip_netifapi_lock(struct netifapi_msg *netifapimsg);
 
 err_t tcpip_callback_with_block(void (*f)(void *ctx), void *ctx, u8_t block);
 #define tcpip_callback(f, ctx)              tcpip_callback_with_block(f, ctx, 1)
-#define tcpip_callback_nonblocking(f, ctx)  tcpip_callback_with_block(f, ctx, 0)
 
-void pbuf_free_int(struct pbuf *p);
+err_t pbuf_free_callback(struct pbuf *p);
+err_t mem_free_callback(void *m);
 
 err_t tcpip_timeout(u32_t msecs, sys_timeout_handler h, void *arg);
 #define tcpip_untimeout(h, arg) tcpip_timeout(0xffffffff, h, arg)