sys_arch.txt, api.h, api_lib.c, api_msg.h, api_msg.c, tcpip.c, sys.h, opt.h: Introduce changes for task #7490 "Add return value to sys_mbox_post" with some modifications in the sys_mbox api: sys_mbox_new take a "size" parameters which indicate the number of pointers query by the mailbox. There is three defines in opt.h to indicate sizes for tcpip::mbox, netconn::recvmbox, and for the netconn::acceptmbox. Port maintainers, you can decide to just add this new parameter in your implementation, but to ignore it to keep the previous behavior. The new sys_mbox_trypost function return a value to know if the mailbox is full or if the message is posted. Take a look to sys_arch.txt for more details. This new function is used in tcpip_input (so, can be called in an interrupt context since the function is not blocking), and in recv_udp and recv_raw.

src/include/lwip/api.h

@@ -98,6 +98,10 @@ struct ip_pcb;
 struct tcp_pcb;
 struct udp_pcb;
 struct raw_pcb;
+struct netconn;
+
+/** A callback prototype to inform about events for a netconn */
+typedef void (* netconn_callback)(struct netconn *, enum netconn_evt, u16_t len);
 
 /** A netconn descriptor */
 struct netconn {
@@ -148,7 +152,7 @@ struct netconn {
   u8_t write_delayed;
 #endif /* LWIP_TCPIP_CORE_LOCKING */
   /** A callback function that is informed about events for this netconn */
-  void (* callback)(struct netconn *, enum netconn_evt, u16_t len);
+  netconn_callback callback;
 };
 
 /* Register an Network connection event */
@@ -161,7 +165,7 @@ struct netconn {
 #define netconn_new_with_callback(t, c) netconn_new_with_proto_and_callback(t, 0, c)
 struct
 netconn *netconn_new_with_proto_and_callback(enum netconn_type t, u8_t proto,
-                                   void (*callback)(struct netconn *, enum netconn_evt, u16_t len));
+                                   netconn_callback callback);
 err_t             netconn_delete  (struct netconn *conn);
 enum netconn_type netconn_type    (struct netconn *conn);
 

src/include/lwip/api_msg.h

@@ -148,9 +148,7 @@ void do_join_leave_group( struct api_msg_msg *msg);
 void do_gethostbyname(void *arg);
 #endif /* LWIP_DNS */
 
-struct netconn* netconn_alloc(
-  enum netconn_type t,
-  void (*callback)(struct netconn *, enum netconn_evt, u16_t len));
+struct netconn* netconn_alloc(enum netconn_type t, netconn_callback callback);
 
 #ifdef __cplusplus
 }

src/include/lwip/opt.h

@@ -874,6 +874,15 @@
 #define TCPIP_THREAD_PRIO               1
 #endif
 
+/**
+ * TCPIP_MBOX_SIZE: The mailbox size for the tcpip thread messages
+ * The queue size value itself is platform-dependent, but is passed to
+ * sys_mbox_new() when tcpip_init is called.
+ */
+#ifndef TCPIP_MBOX_SIZE
+#define TCPIP_MBOX_SIZE                 0
+#endif
+
 /**
  * SLIPIF_THREAD_NAME: The name assigned to the slipif_loop thread.
  */
@@ -949,6 +958,24 @@
 #define DEFAULT_THREAD_PRIO             1
 #endif
 
+/**
+ * DEFAULT_RECVMBOX_SIZE: The mailbox size for the incoming packets.
+ * The queue size value itself is platform-dependent, but is passed to
+ * sys_mbox_new() when the recvmbox is created.
+ */
+#ifndef DEFAULT_RECVMBOX_SIZE
+#define DEFAULT_RECVMBOX_SIZE           0
+#endif
+
+/**
+ * DEFAULT_ACCEPTMBOX_SIZE: The mailbox size for the incoming connections.
+ * The queue size value itself is platform-dependent, but is passed to
+ * sys_mbox_new() when the acceptmbox is created.
+ */
+#ifndef DEFAULT_ACCEPTMBOX_SIZE
+#define DEFAULT_ACCEPTMBOX_SIZE         0
+#endif
+
 /*
    ----------------------------------------------
    ---------- Sequential layer options ----------

src/include/lwip/sys.h

@@ -56,9 +56,11 @@ struct sys_timeo {u8_t dummy;};
 #define sys_sem_wait_timeout(s,t)
 #define sys_arch_sem_wait(s,t)
 #define sys_sem_free(s)
-#define sys_mbox_new() 0
+#define sys_mbox_new(s) 0
 #define sys_mbox_fetch(m,d)
+#define sys_mbox_tryfetch(m,d)
 #define sys_mbox_post(m,d)
+#define sys_mbox_trypost(m,d)
 #define sys_mbox_free(m)
 
 #define sys_thread_new(n,t,a,s,p)
@@ -73,6 +75,7 @@ struct sys_timeo {u8_t dummy;};
  */
 #define SYS_MBOX_EMPTY SYS_ARCH_TIMEOUT 
 
+#include "lwip/err.h"
 #include "arch/sys_arch.h"
 
 typedef void (* sys_timeout_handler)(void *arg);
@@ -121,8 +124,9 @@ u32_t sys_jiffies(void); /* since power up. */
 #endif
 
 /* Mailbox functions. */
-sys_mbox_t sys_mbox_new(void);
+sys_mbox_t sys_mbox_new(int size);
 void sys_mbox_post(sys_mbox_t mbox, void *msg);
+err_t sys_mbox_trypost(sys_mbox_t mbox, void *msg);
 u32_t sys_arch_mbox_fetch(sys_mbox_t mbox, void **msg, u32_t timeout);
 #ifndef sys_arch_mbox_tryfetch /* Allow port to override with a macro */
 u32_t sys_arch_mbox_tryfetch(sys_mbox_t mbox, void **msg);