From 20efa14e5c188738c15a013e092af51b780fde61 Mon Sep 17 00:00:00 2001
From: Thomas Graf <tgraf@suug.ch>
Date: Thu, 15 Nov 2012 21:30:57 +0100
Subject: lock abstraction layer

Hide pthread availability and enablement behind internal API

Signed-off-by: Thomas Graf <tgraf@suug.ch>
---
 include/netlink-local.h | 50 +++++++++++++++++++++++++++++++++++++++++++++++++
 lib/socket.c            | 28 ++++++---------------------
 2 files changed, 56 insertions(+), 22 deletions(-)

diff --git a/include/netlink-local.h b/include/netlink-local.h
index 01c611a..1f580c6 100644
--- a/include/netlink-local.h
+++ b/include/netlink-local.h
@@ -53,6 +53,10 @@
 #include <linux/ipv6.h>
 #include <linux/snmp.h>
 
+#ifndef DISABLE_PTHREADS
+#include <pthread.h>
+#endif
+
 #include <netlink/netlink.h>
 #include <netlink/handlers.h>
 #include <netlink/cache.h>
@@ -210,4 +214,50 @@ static inline int build_sysconf_path(char **strp, const char *filename)
 	return asprintf(strp, "%s/%s", sysconfdir, filename);
 }
 
+#ifndef DISABLE_PTHREADS
+#define NL_LOCK(NAME) pthread_mutex_t (NAME) = PTHREAD_MUTEX_INITIALIZER
+#define NL_RW_LOCK(NAME) pthread_rwlock_t (NAME) = PTHREAD_RWLOCK_INITIALIZER
+
+static inline void nl_lock(pthread_mutex_t *lock)
+{
+	pthread_mutex_lock(lock);
+}
+
+static inline void nl_unlock(pthread_mutex_t *lock)
+{
+	pthread_mutex_unlock(lock);
+}
+
+static inline void nl_read_lock(pthread_rwlock_t *lock)
+{
+	pthread_rwlock_rdlock(lock);
+}
+
+static inline void nl_read_unlock(pthread_rwlock_t *lock)
+{
+	pthread_rwlock_unlock(lock);
+}
+
+static inline void nl_write_lock(pthread_rwlock_t *lock)
+{
+	pthread_rwlock_wrlock(lock);
+}
+
+static inline void nl_write_unlock(pthread_rwlock_t *lock)
+{
+	pthread_rwlock_unlock(lock);
+}
+
+#else
+#define NL_LOCK(NAME) int __unused_lock_ ##NAME __attribute__((unused))
+#define NL_RW_LOCK(NAME) int __unused_lock_ ##NAME __attribute__((unused))
+
+#define nl_lock(LOCK) do { } while(0)
+#define nl_unlock(LOCK) do { } while(0)
+#define nl_read_lock(LOCK) do { } while(0)
+#define nl_read_unlock(LOCK) do { } while(0)
+#define nl_write_lock(LOCK) do { } while(0)
+#define nl_write_unlock(LOCK) do { } while(0)
+#endif
+
 #endif
diff --git a/lib/socket.c b/lib/socket.c
index 0335f07..b30058b 100644
--- a/lib/socket.c
+++ b/lib/socket.c
@@ -29,10 +29,6 @@
 
 #include "defs.h"
 
-#ifndef DISABLE_PTHREADS
-#include <pthread.h>
-#endif
-
 #include <netlink-local.h>
 #include <netlink/netlink.h>
 #include <netlink/utils.h>
@@ -61,18 +57,14 @@ 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 NL_RW_LOCK(port_map_lock);
 
 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
+	nl_write_lock(&port_map_lock);
 
 	for (i = 0; i < 32; i++) {
 		if (used_ports_map[i] == 0xFFFFFFFF)
@@ -88,17 +80,13 @@ 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
+			nl_write_unlock(&port_map_lock);
 
 			return pid + (n << 22);
 		}
 	}
 
-#ifndef DISABLE_PTHREADS
-	pthread_mutex_unlock(&port_map_mutex);
-#endif
+	nl_write_unlock(&port_map_lock);
 
 	/* Out of sockets in our own PID namespace, what to do? FIXME */
 	return UINT_MAX;
@@ -113,13 +101,9 @@ static void release_local_port(uint32_t port)
 	
 	nr = port >> 22;
 
-#ifndef DISABLE_PTHREADS
-	pthread_mutex_lock(&port_map_mutex);
-#endif
+	nl_write_lock(&port_map_lock);
 	used_ports_map[nr / 32] &= ~(1 << (nr % 32));
-#ifndef DISABLE_PTHREADS
-	pthread_mutex_unlock(&port_map_mutex);
-#endif
+	nl_write_unlock(&port_map_lock);
 }
 
 /**
-- 
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