fix(el): Treat some accept() errors as temporary

If accept() fails, some of the error codes indicate failure with the
incoming connection, not the server socket. Do not kill the server
socket if one of those error codes are detected.

arch/eventloop_posix/eventloop_posix.h

@@ -55,10 +55,16 @@ typedef SSIZE_T ssize_t;
 #define UA_AGAIN EAGAIN /* the same as wouldblock on nearly every system */
 #define UA_INPROGRESS WSAEINPROGRESS
 #define UA_WOULDBLOCK WSAEWOULDBLOCK
+#define UA_CONNRESET WSAECONNRESET
+#define UA_NOBUFS WSAENOBUFS
+#define UA_MFILE WSAEMFILE
 #define UA_POLLIN POLLRDNORM
 #define UA_POLLOUT POLLWRNORM
 #define UA_SHUT_RDWR SD_BOTH
 
+#define UA_IS_TEMPORARY_ACCEPT_ERROR(err) \
+    ((err) == UA_INTERRUPTED || (err) == UA_CONNRESET || (err) == UA_NOBUFS || (err) == UA_MFILE)
+
 #define UA_getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) \
     getnameinfo(sa, (socklen_t)salen, host, (DWORD)hostlen, serv, (DWORD)servlen, flags)
 #define UA_poll(fds,nfds,timeout) WSAPoll((LPWSAPOLLFD)fds, nfds, timeout)
@@ -136,10 +142,17 @@ typedef int SOCKET;
 #define UA_AGAIN EAGAIN /* the same as wouldblock on nearly every system */
 #define UA_INPROGRESS EINPROGRESS
 #define UA_WOULDBLOCK EWOULDBLOCK
+#define UA_CONNABORTED ECONNABORTED
+#define UA_MFILE EMFILE
+#define UA_NFILE ENFILE
+#define UA_NOBUFS ENOBUFS
 #define UA_POLLIN POLLIN
 #define UA_POLLOUT POLLOUT
 #define UA_SHUT_RDWR SHUT_RDWR
 
+#define UA_IS_TEMPORARY_ACCEPT_ERROR(err) \
+    ((err) == UA_INTERRUPTED || (err) == UA_CONNABORTED || (err) == UA_MFILE || (err) == UA_NFILE || (err) == UA_NOBUFS)
+
 #define UA_getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) \
     getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
 #define UA_poll poll

arch/eventloop_posix/eventloop_posix_tcp.c

@@ -250,7 +250,7 @@ TCP_listenSocketCallback(UA_ConnectionManager *cm, TCP_FD *conn, short event) {
     UA_FD newsockfd = accept(conn->rfd.fd, (struct sockaddr*)&remote, &remote_size);
     if(newsockfd == UA_INVALID_FD) {
         /* Temporary error -- retry */
-        if(UA_ERRNO == UA_INTERRUPTED)
+        if(UA_IS_TEMPORARY_ACCEPT_ERROR(UA_ERRNO))
             return;
 
         /* Close the listen socket */