Add build glue and NetBSD-specific changes. The changes have been fed…

… upstream:

urcu/userspace-rcu#27

external/lgpl2/userspace-rcu/Makefile.inc

@@ -0,0 +1,11 @@
+# $Makefile$
+
+URCU:= ${.PARSEDIR}
+URCU_DIST= ${URCU}/dist
+
+.PATH.c: ${URCU_DIST}/src
+
+CPPFLAGS+=	-DHAVE_CONFIG_H -include ${URCU}/include/urcu/config.h
+CPPFLAGS+=	-I${URCU}/include -I${URCU_DIST}/include
+CFLAGS+=	-pthread
+LDFLAGS+=	-pthread

external/lgpl2/userspace-rcu/dist/include/urcu/futex.h

@@ -37,6 +37,12 @@
 # include <sys/time.h>
 # include <sys/futex.h>
 
+#elif defined(__NetBSD__) && defined(SYS___futex)
+
+# include <unistd.h>
+# include <sys/time.h>
+# include <sys/futex.h>
+
 #endif
 
 #ifdef __cplusplus
@@ -200,6 +206,41 @@ static inline int futex_async(int32_t *uaddr, int op, int32_t val,
 	return ret;
 }
 
+#elif defined(__NetBSD__) && defined(SYS___futex)
+
+static inline int futex(int32_t *uaddr, int op, int32_t val,
+		const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
+{
+	return syscall(SYS___futex, uaddr, op, val, timeout, uaddr2, 0, val3);
+}
+
+static inline int futex_noasync(int32_t *uaddr, int op, int32_t val,
+		const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
+{
+	int ret;
+
+	ret = futex(uaddr, op, val, timeout, uaddr2, val3);
+	if (caa_unlikely(ret < 0 && errno == ENOSYS)) {
+		return compat_futex_async(uaddr, op, val, timeout,
+				uaddr2, val3);
+	}
+	return ret;
+
+}
+
+static inline int futex_async(int32_t *uaddr, int op, int32_t val,
+		const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
+{
+	int ret;
+
+	ret = futex(uaddr, op, val, timeout, uaddr2, val3);
+	if (caa_unlikely(ret < 0 && errno == ENOSYS)) {
+		return compat_futex_async(uaddr, op, val, timeout,
+				uaddr2, val3);
+	}
+	return ret;
+}
+
 #elif defined(__CYGWIN__)
 
 /*

external/lgpl2/userspace-rcu/dist/include/urcu/syscall-compat.h

@@ -13,6 +13,8 @@
 #include <sys/syscall.h>
 #elif defined(__linux__) || defined(__GLIBC__)
 #include <syscall.h>
+#elif defined(__NetBSD__)
+#include <sys/syscall.h>
 
 #elif defined(__CYGWIN__) || defined(__APPLE__) || \
 	defined(__FreeBSD__) || defined(__DragonFly__) || \

external/lgpl2/userspace-rcu/dist/tests/common/thread-id.h

@@ -67,6 +67,14 @@ unsigned long urcu_get_thread_id(void)
 {
 	return (unsigned long) getthrid();
 }
+#elif defined(__NetBSD__)
+#include <lwp.h>
+
+static inline
+unsigned long urcu_get_thread_id(void)
+{
+	return (unsigned long) _lwp_self();
+}
 #else
 # warning "use pid as thread ID"
 static inline