From 8fc20142f7b1b18f24fc48187d390187d718ce30 Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon@gmx.de>
Date: Fri, 5 Jan 2018 21:08:27 +0100
Subject: [PATCH] Added sys_mbox_trypost_fromisr() and
 tcpip_callbackmsg_trycallback_fromisr()

This can be used to post preallocated messages from an ISR to the tcpip thread
when using FreeRTOS, where where calls differ between task level and ISR level.

Signed-off-by: goldsimon <goldsimon@gmx.de>
---
 src/api/tcpip.c          | 19 +++++++++++++++++++
 src/include/lwip/sys.h   | 12 +++++++++++-
 src/include/lwip/tcpip.h |  1 +
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/api/tcpip.c b/src/api/tcpip.c
index ff01032b..1176c11c 100644
--- a/src/api/tcpip.c
+++ b/src/api/tcpip.c
@@ -531,6 +531,25 @@ tcpip_callbackmsg_trycallback(struct tcpip_callback_msg *msg)
   return sys_mbox_trypost(&mbox, msg);
 }
 
+/**
+ * @ingroup lwip_os
+ * Try to post a callback-message to the tcpip_thread mbox.
+ * Same as @ref tcpip_callbackmsg_trycallback but calls sys_mbox_trypost_fromisr(),
+ * mainly to help FreeRTOS, where calls differ between task level and ISR level.
+ *
+ * @param msg pointer to the message to post
+ * @return sys_mbox_trypost_fromisr() return code (without change, so this
+ *         knowledge can be used to e.g. propagate "bool needs_scheduling")
+ *
+ * @see tcpip_callbackmsg_new()
+ */
+err_t
+tcpip_callbackmsg_trycallback_fromisr(struct tcpip_callback_msg *msg)
+{
+  LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
+  return sys_mbox_trypost_fromisr(&mbox, msg);
+}
+
 /**
  * @ingroup lwip_os
  * Initialize this module:
diff --git a/src/include/lwip/sys.h b/src/include/lwip/sys.h
index 771b8d3b..168e465b 100644
--- a/src/include/lwip/sys.h
+++ b/src/include/lwip/sys.h
@@ -295,13 +295,23 @@ void sys_mbox_post(sys_mbox_t *mbox, void *msg);
 /**
  * @ingroup sys_mbox
  * Try to post a message to an mbox - may fail if full.
- * Can be used from ISR.
+ * Can be used from ISR (if the sys arch layer allows this).
  * Returns ERR_MEM if it is full, else, ERR_OK if the "msg" is posted.
  * 
  * @param mbox mbox to posts the message
  * @param msg message to post (ATTENTION: can be NULL)
  */
 err_t sys_mbox_trypost(sys_mbox_t *mbox, void *msg);
+/**
+ * @ingroup sys_mbox
+ * Try to post a message to an mbox - may fail if full.
+ * To be be used from ISR.
+ * Returns ERR_MEM if it is full, else, ERR_OK if the "msg" is posted.
+ * 
+ * @param mbox mbox to posts the message
+ * @param msg message to post (ATTENTION: can be NULL)
+ */
+err_t sys_mbox_trypost_fromisr(sys_mbox_t *mbox, void *msg);
 /**
  * @ingroup sys_mbox
  * Blocks the thread until a message arrives in the mailbox, but does
diff --git a/src/include/lwip/tcpip.h b/src/include/lwip/tcpip.h
index b4cd7aaa..0b8880a9 100644
--- a/src/include/lwip/tcpip.h
+++ b/src/include/lwip/tcpip.h
@@ -89,6 +89,7 @@ err_t  tcpip_callback(tcpip_callback_fn function, void *ctx);
 struct tcpip_callback_msg* tcpip_callbackmsg_new(tcpip_callback_fn function, void *ctx);
 void   tcpip_callbackmsg_delete(struct tcpip_callback_msg* msg);
 err_t  tcpip_callbackmsg_trycallback(struct tcpip_callback_msg* msg);
+err_t  tcpip_callbackmsg_trycallback_fromisr(struct tcpip_callback_msg* msg);
 
 /* free pbufs or heap memory from another context without blocking */
 err_t  pbuf_free_callback(struct pbuf *p);