From 0aedff662392cddb35d29654013f154d38af6c52 Mon Sep 17 00:00:00 2001
From: Daniel O'Connor <darius@dons.net.au>
Date: Mon, 14 Oct 2019 10:14:25 +1030
Subject: [PATCH] Set the accepted to socket to be blocking as that is what the
 code expects. This is necessary on OSX (and probably BSDs) where they default
 to non blocking which causes recv() to return -1 with errno set to EAGAIN.

---
 src/platforms/pc/gdb_if.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/platforms/pc/gdb_if.c b/src/platforms/pc/gdb_if.c
index b5583b6..6a81a0d 100644
--- a/src/platforms/pc/gdb_if.c
+++ b/src/platforms/pc/gdb_if.c
@@ -98,14 +98,18 @@ unsigned char gdb_if_getchar(void)
 {
 	unsigned char ret;
 	int i = 0;
-
+#if defined(_WIN32) || defined(__CYGWIN__)
+	unsigned long opt;
+#else
+	int flags;
+#endif
 	while(i <= 0) {
 		if(gdb_if_conn <= 0) {
 #if defined(_WIN32) || defined(__CYGWIN__)
-			unsigned long opt = 1;
+			opt = 1;
 			ioctlsocket(gdb_if_serv, FIONBIO, &opt);
 #else
-			int flags = fcntl(gdb_if_serv, F_GETFL);
+			flags = fcntl(gdb_if_serv, F_GETFL);
 			fcntl(gdb_if_serv, F_SETFL, flags | O_NONBLOCK);
 #endif
 			while(1) {
@@ -115,12 +119,12 @@ unsigned char gdb_if_getchar(void)
 						SET_IDLE_STATE(1);
 						platform_delay(100);
 					} else {
-						DEBUG("error when accepting connection");
+						DEBUG("error when accepting connection: %s", strerror(errno));
 						exit(1);
 					}
 				} else {
 #if defined(_WIN32) || defined(__CYGWIN__)
-					unsigned long opt = 0;
+					opt = 0;
 					ioctlsocket(gdb_if_serv, FIONBIO, &opt);
 #else
 					fcntl(gdb_if_serv, F_SETFL, flags);
@@ -129,11 +133,18 @@ unsigned char gdb_if_getchar(void)
 				}
 			}
 			DEBUG("Got connection\n");
+#if defined(_WIN32) || defined(__CYGWIN__)
+			opt = 0;
+			ioctlsocket(gdb_if_conn, FIONBIO, &opt);
+#else
+			flags = fcntl(gdb_if_conn, F_GETFL);
+			fcntl(gdb_if_conn, F_SETFL, flags & ~O_NONBLOCK);
+#endif
 		}
 		i = recv(gdb_if_conn, (void*)&ret, 1, 0);
 		if(i <= 0) {
 			gdb_if_conn = -1;
-			DEBUG("Dropped broken connection\n");
+			DEBUG("Dropped broken connection: %s\n", strerror(errno));
 			/* Return '+' in case we were waiting for an ACK */
 			return '+';
 		}