Added an overridable define to get informed when the tcpip_thread processes messages or timeouts to implement a watchdog.

CHANGELOG

@@ -13,6 +13,10 @@ HISTORY
 
   ++ New features:
 
+  2010-04-14: Simon Goldschmidt
+  * tcpip.h/.c, timers.c: Added an overridable define to get informed when the
+    tcpip_thread processes messages or timeouts to implement a watchdog.
+
   2010-03-28: Simon Goldschmidt
   * ip_frag.c: create a new (contiguous) PBUF_RAM for every outgoing
     fragment if LWIP_NETIF_TX_SINGLE_PBUF==1

src/api/tcpip.c

@@ -83,6 +83,7 @@ tcpip_thread(void *arg)
   LOCK_TCPIP_CORE();
   while (1) {                          /* MAIN Loop */
     UNLOCK_TCPIP_CORE();
+    LWIP_TCPIP_THREAD_ALIVE();
     /* wait for a message, timeouts are processed while waiting */
     sys_timeouts_mbox_fetch(&mbox, (void **)&msg);
     LOCK_TCPIP_CORE();

src/core/timers.c

@@ -467,6 +467,7 @@ sys_timeouts_mbox_fetch(sys_mbox_t *mbox, void **msg)
         h(arg);
         UNLOCK_TCPIP_CORE();
       }
+      LWIP_TCPIP_THREAD_ALIVE();
 
       /* We try again to fetch a message from the mbox. */
       goto again;

src/include/lwip/tcpip.h

@@ -48,6 +48,12 @@
 extern "C" {
 #endif
 
+/** Define this to something that triggers a watchdog. This is called from
+ * tcpip_thread after processing a message. */
+#ifndef LWIP_TCPIP_THREAD_ALIVE
+#define LWIP_TCPIP_THREAD_ALIVE()
+#endif
+
 #if LWIP_TCPIP_CORE_LOCKING
 /** The global semaphore to lock the stack. */
 extern sys_mutex_t lock_tcpip_core;