From 940d824be0a4d0f62f6819cf890c4b1a05a104c4 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Sun, 26 Sep 2021 14:54:24 +0900
Subject: [PATCH] [util] Split out the select code to Sys_Select

While select itself is fairly portable, it's not super convenient.
---
 include/QF/sys.h |  2 ++
 libs/util/sys.c  | 35 ++++++++++++++++++++++++++---------
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/include/QF/sys.h b/include/QF/sys.h
index abf7d4e37..a012062bc 100644
--- a/include/QF/sys.h
+++ b/include/QF/sys.h
@@ -37,6 +37,7 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <stdarg.h>
+#include <sys/select.h>
 
 extern	struct cvar_s	*sys_nostdout;
 extern	struct cvar_s	*sys_extrasleep;
@@ -100,6 +101,7 @@ enum {
 #include "QF/sys_developer.h"
 };
 
+int Sys_Select (int maxfd, fd_set *fdset, int64_t usec);
 int Sys_CheckInput (int idle, int net_socket);
 const char *Sys_ConsoleInput (void);
 
diff --git a/libs/util/sys.c b/libs/util/sys.c
index 9aad2ee6b..5f1de8986 100644
--- a/libs/util/sys.c
+++ b/libs/util/sys.c
@@ -720,13 +720,32 @@ Sys_DebugLog (const char *file, const char *fmt, ...)
 	}
 }
 
+VISIBLE int
+Sys_Select (int maxfd, fd_set *fdset, int64_t usec)
+{
+	struct timeval _timeout;
+	struct timeval *timeout = 0;
+
+	if (usec >= 0) {
+		timeout = &_timeout;
+		if (usec < 1000000) {
+			_timeout.tv_sec = 0;
+			_timeout.tv_usec = usec;
+		} else {
+			_timeout.tv_sec = usec / 1000000;
+			_timeout.tv_usec = usec % 1000000;
+		}
+	}
+
+	return select (maxfd + 1, fdset, NULL, NULL, timeout);
+}
+
 VISIBLE int
 Sys_CheckInput (int idle, int net_socket)
 {
 	fd_set      fdset;
 	int         res;
-	struct timeval _timeout;
-	struct timeval *timeout = 0;
+	int64_t     usec;
 
 #ifdef _WIN32
 	int         sleep_msec;
@@ -739,11 +758,9 @@ Sys_CheckInput (int idle, int net_socket)
 		Sleep (sleep_msec);
 	}
 
-	_timeout.tv_sec = 0;
-	_timeout.tv_usec = net_socket < 0 ? 0 : 20;
+	usec = net_socket < 0 ? 0 : 20;
 #else
-	_timeout.tv_sec = 0;
-	_timeout.tv_usec = net_socket < 0 ? 0 : 2000;
+	usec = net_socket < 0 ? 0 : 2000;
 #endif
 	// select on the net socket and stdin
 	// the only reason we have a timeout at all is so that if the last
@@ -757,10 +774,10 @@ Sys_CheckInput (int idle, int net_socket)
 	if (net_socket >= 0)
 		FD_SET (((unsigned) net_socket), &fdset);	// cast needed for windows
 
-	if (!idle || !sys_dead_sleep->int_val)
-		timeout = &_timeout;
+	if (idle && sys_dead_sleep->int_val)
+		usec = -1;
 
-	res = select (max (net_socket, 0) + 1, &fdset, NULL, NULL, timeout);
+	res = Sys_Select (max (net_socket, 0), &fdset, usec);
 	if (res == 0 || res == -1)
 		return 0;
 #ifndef _WIN32