From a8ef3525c89b0a2049abedd2a0b2d54f0d574476 Mon Sep 17 00:00:00 2001
From: Rich Fought <rmf.aero@gmail.com>
Date: Fri, 26 Oct 2012 12:19:26 -0700
Subject: [PATCH] Add configure option to disable pthreads support

---
 configure.in | 14 ++++++++++++--
 lib/socket.c | 16 ++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/configure.in b/configure.in
index 79cd93f..9a190c2 100644
--- a/configure.in
+++ b/configure.in
@@ -41,7 +41,7 @@ m4_define([libnl_lt_age],        [11])
 m4_define([libnl_version],
 	  [libnl_major_version.libnl_minor_version.libnl_micro_version])
 
-AC_INIT(libnl, [libnl_version], [http://www.infradead.org/~tgr/libnl/])
+AC_INIT(libnl, [libnl_version], [], [], [http://www.infradead.org/~tgr/libnl/])
 AC_CONFIG_HEADERS([lib/defs.h])
 AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE([-Wall foreign subdir-objects])
@@ -83,8 +83,18 @@ AC_ARG_ENABLE([cli],
 	[enable_cli="$enableval"], [enable_cli="yes"])
 AM_CONDITIONAL([ENABLE_CLI], [test "$enable_cli" = "yes"])
 
+AC_ARG_ENABLE([pthreads],
+	AS_HELP_STRING([--disable-pthreads], [Disable pthreads support]),
+	[enable_pthreads="$enableval"], [enable_pthreads="yes"])
+AM_CONDITIONAL([DISABLE_PTHREADS], [test "$enable_pthreads" = "no"])
+
 AC_CHECK_LIB([m], [pow], [], AC_MSG_ERROR([libm is required]))
-AC_CHECK_LIB([pthread], [pthread_mutex_lock], [], AC_MSG_ERROR([libpthread is required]))
+
+if test "x$enable_pthreads" = "xno"; then
+    AC_DEFINE([DISABLE_PTHREADS], [1], [Define to 1 to disable pthreads])
+else
+    AC_CHECK_LIB([pthread], [pthread_mutex_lock], [], AC_MSG_ERROR([libpthread is required]))
+fi
 
 AC_CONFIG_SUBDIRS([doc])
 
diff --git a/lib/socket.c b/lib/socket.c
index d53a714..4e1d84c 100644
--- a/lib/socket.c
+++ b/lib/socket.c
@@ -27,7 +27,11 @@
  * ~~~~
  */
 
+#include "defs.h"
+
+#ifndef DISABLE_PTHREADS
 #include <pthread.h>
+#endif
 
 #include <netlink-local.h>
 #include <netlink/netlink.h>
@@ -57,14 +61,18 @@ static void __init init_default_cb(void)
 }
 
 static uint32_t used_ports_map[32];
+#ifndef DISABLE_PTHREADS
 static pthread_mutex_t port_map_mutex = PTHREAD_MUTEX_INITIALIZER;
+#endif
 
 static uint32_t generate_local_port(void)
 {
 	int i, n;
 	uint32_t pid = getpid() & 0x3FFFFF;
 
+#ifndef DISABLE_PTHREADS
 	pthread_mutex_lock(&port_map_mutex);
+#endif
 
 	for (i = 0; i < 32; i++) {
 		if (used_ports_map[i] == 0xFFFFFFFF)
@@ -80,13 +88,17 @@ static uint32_t generate_local_port(void)
 			/* PID_MAX_LIMIT is currently at 2^22, leaving 10 bit
 			 * to, i.e. 1024 unique ports per application. */
 
+#ifndef DISABLE_PTHREADS
 			pthread_mutex_unlock(&port_map_mutex);
+#endif
 
 			return pid + (n << 22);
 		}
 	}
 
+#ifndef DISABLE_PTHREADS
 	pthread_mutex_unlock(&port_map_mutex);
+#endif
 
 	/* Out of sockets in our own PID namespace, what to do? FIXME */
 	return UINT_MAX;
@@ -101,9 +113,13 @@ static void release_local_port(uint32_t port)
 	
 	nr = port >> 22;
 
+#ifndef DISABLE_PTHREADS
 	pthread_mutex_lock(&port_map_mutex);
+#endif
 	used_ports_map[nr / 32] &= ~(1 << (nr % 32));
+#ifndef DISABLE_PTHREADS
 	pthread_mutex_unlock(&port_map_mutex);
+#endif
 }
 
 /**