From ef1d4580892f2350b8c6fb9c8e65d0d6e293cb46 Mon Sep 17 00:00:00 2001
From: "Martine S. Lenders" <mail@martine-lenders.eu>
Date: Tue, 12 May 2020 14:17:32 +0200
Subject: [PATCH] lwip_sock: re-issue receive events if there are still
 received messages

... after `*_recv()` or `*_accept()` was called.

This prevents a client from needing to call `*_recv()` or `*_accept()`
in a loop.
---
 pkg/lwip/contrib/sock/lwip_sock.c         | 7 +++++++
 pkg/lwip/contrib/sock/tcp/lwip_sock_tcp.c | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/pkg/lwip/contrib/sock/lwip_sock.c b/pkg/lwip/contrib/sock/lwip_sock.c
index 11680fd298..a65a9c4540 100644
--- a/pkg/lwip/contrib/sock/lwip_sock.c
+++ b/pkg/lwip/contrib/sock/lwip_sock.c
@@ -548,6 +548,13 @@ int lwip_sock_recv(struct netconn *conn, uint32_t timeout, struct netbuf **buf)
     /* unset flags */
 #if LWIP_SO_RCVTIMEO
     netconn_set_recvtimeout(conn, 0);
+#endif
+#if IS_ACTIVE(SOCK_HAS_ASYNC)
+    lwip_sock_base_t *sock = netconn_get_callback_arg(conn);
+
+    if (sock && sock->async_cb.gen && cib_avail(&conn->recvmbox.mbox.cib)) {
+        sock->async_cb.gen(sock, SOCK_ASYNC_MSG_RECV, sock->async_cb_arg);
+    }
 #endif
     return res;
 }
diff --git a/pkg/lwip/contrib/sock/tcp/lwip_sock_tcp.c b/pkg/lwip/contrib/sock/tcp/lwip_sock_tcp.c
index ae403a153a..c9764f25d8 100644
--- a/pkg/lwip/contrib/sock/tcp/lwip_sock_tcp.c
+++ b/pkg/lwip/contrib/sock/tcp/lwip_sock_tcp.c
@@ -254,6 +254,13 @@ int sock_tcp_accept(sock_tcp_queue_t *queue, sock_tcp_t **sock,
     }
 #if LWIP_SO_RCVTIMEO
     netconn_set_recvtimeout(queue->base.conn, 0);
+#endif
+#if IS_ACTIVE(SOCK_HAS_ASYNC)
+    if (queue->base.async_cb.gen &&
+        cib_avail(&queue->base.conn->acceptmbox.mbox.cib)) {
+        queue->base.async_cb.gen(&queue->base, SOCK_ASYNC_CONN_RECV,
+                                 queue->base.async_cb_arg);
+    }
 #endif
     mutex_unlock(&queue->mutex);
     return res;