test: Add usnix-socket test

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

test/Makefile

@@ -5,6 +5,7 @@ SRCS	+= test-shmem-three-async.c
 SRCS	+= test-pipe-async.c
 SRCS	+= test-vdso.c
 SRCS	+= test-sigaction.c
+SRCS	+= test-unixsocket.c
 
 SRCS-TH	+= test-pthreads.c
 OBJS-TH += $(patsubst %.c,%.o,$(SRCS-TH))

test/test-unixsocket.c

@@ -0,0 +1,44 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/un.h>
+
+int main(void)
+{
+	int sv[2];
+	char buf;
+	int ret;
+
+	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == -1) {
+		perror("socketpair");
+		exit(1);
+	}
+
+	buf = 'a';
+	write(sv[0], &buf, 1);
+	printf("sent '%c'\n", buf);
+
+	while (1) {
+		/* stream */
+		read(sv[1], &buf, 1);
+		printf("read '%c'\n", buf);
+
+		/*
+		 * checkpoint should be done here,
+		 * we don't support queued data yet.
+		 */
+		printf("pause\n");
+		sleep(10);
+
+		buf = toupper(buf);
+		write(sv[0], &buf, 1);
+		printf("sent '%c'\n", buf);
+	}
+
+	return 0;
+}