From ea174560b1350454f8c2c9f5494ab9331bac4665 Mon Sep 17 00:00:00 2001
From: Dirk Ziegelmeier <dirk@ziegelmeier.net>
Date: Wed, 16 Mar 2016 20:14:52 +0100
Subject: [PATCH] tcpip.c tcpip_send_api_msg: Handle core locking case
 internally

---
 src/api/tcpip.c                    | 22 +++++++++++++++-------
 src/include/lwip/priv/tcpip_priv.h |  2 --
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/src/api/tcpip.c b/src/api/tcpip.c
index 73563b7d..de4842b0 100644
--- a/src/api/tcpip.c
+++ b/src/api/tcpip.c
@@ -312,10 +312,11 @@ tcpip_untimeout(sys_timeout_handler h, void *arg)
 #endif /* LWIP_TCPIP_TIMEOUT */
 
 
-#if !LWIP_TCPIP_CORE_LOCKING
 /**
- * Generic way to dispatch an API message in TCPIP thread and wait for its
- * completion by blocking on a semaphore.
+ * Synchronously calls function in TCPIP thread and waits for its completion
+ * by blocking on a provided semaphore pointer.
+ * It is recommended to use LWIP_TCPIP_CORE_LOCKING since this is the way
+ * with least runtime overhead.
  *
  * @param fn function to be called from TCPIP thread
  * @param apimsg argument to API function
@@ -327,6 +328,13 @@ tcpip_send_api_msg(tcpip_callback_fn fn, void *apimsg, sys_sem_t* sem)
 {
   LWIP_ASSERT("semaphore not initialized", sys_sem_valid(sem));
 
+#if LWIP_TCPIP_CORE_LOCKING
+  LOCK_TCPIP_CORE();
+  fn(apimsg);
+  UNLOCK_TCPIP_CORE();
+  sys_arch_sem_wait(sem, 0);
+  return ERR_OK;
+#else /* LWIP_TCPIP_CORE_LOCKING */
   if (sys_mbox_valid_val(mbox)) {
     TCPIP_MSG_VAR_DECLARE(msg);
     
@@ -340,13 +348,13 @@ tcpip_send_api_msg(tcpip_callback_fn fn, void *apimsg, sys_sem_t* sem)
     return ERR_OK;
   }
   return ERR_VAL;
+#endif /* LWIP_TCPIP_CORE_LOCKING */
 }
-#endif /* !LWIP_TCPIP_CORE_LOCKING */
 
 /**
  * Synchronously calls function in TCPIP thread and waits for its completion.
  * It is recommended to use LWIP_TCPIP_CORE_LOCKING (preferred) or
- * LWIP_NETCONN_SEM_PER_THREAD.
+ * LWIP_NETCONN_SEM_PER_THREAD. 
  * If not, a semaphore is created and destroyed on every call which is usually
  * an expensive/slow operation.
  * @param fn Function to call
@@ -361,7 +369,7 @@ err_t tcpip_api_call(tcpip_api_call_fn fn, struct tcpip_api_call *call)
   err = fn(call);
   UNLOCK_TCPIP_CORE();
   return err;
-#else
+#else /* LWIP_TCPIP_CORE_LOCKING */
   if (sys_mbox_valid_val(mbox)) {
     TCPIP_MSG_VAR_DECLARE(msg);
     err_t err;
@@ -390,7 +398,7 @@ err_t tcpip_api_call(tcpip_api_call_fn fn, struct tcpip_api_call *call)
     return ERR_OK;
   }
   return ERR_VAL;
-#endif
+#endif /* LWIP_TCPIP_CORE_LOCKING */
 }
 
 /**
diff --git a/src/include/lwip/priv/tcpip_priv.h b/src/include/lwip/priv/tcpip_priv.h
index cc1c54eb..24c19a56 100644
--- a/src/include/lwip/priv/tcpip_priv.h
+++ b/src/include/lwip/priv/tcpip_priv.h
@@ -95,9 +95,7 @@ extern sys_mutex_t lock_tcpip_core;
 #define API_EXPR_DEREF(expr)            *(expr)
 #endif /* LWIP_MPU_COMPATIBLE */
 
-#if !LWIP_TCPIP_CORE_LOCKING
 err_t tcpip_send_api_msg(tcpip_callback_fn fn, void *apimsg, sys_sem_t* sem);
-#endif /* !LWIP_TCPIP_CORE_LOCKING */
 
 struct tcpip_api_call;
 typedef err_t (*tcpip_api_call_fn)(struct tcpip_api_call* call);