Reuse abadoned unix socket. Fixed #1395

src/evio.cc

@@ -194,6 +194,32 @@ evio_service_accept_cb(ev_loop * /* loop */, ev_io *watcher,
 	}
 }
 
+static bool
+evio_service_reuse_addr(struct evio_service *service)
+{
+	if ((service->addr.sa_family != AF_UNIX) || (errno != EADDRINUSE))
+		return false;
+	int save_errno = errno;
+	int cl_fd = sio_socket(service->addr.sa_family,
+		SOCK_STREAM, 0);
+
+	if (connect(cl_fd, &service->addr, service->addr_len) == 0)
+		goto err;
+
+	if (errno != ECONNREFUSED)
+		goto err;
+
+	if (unlink(((struct sockaddr_un *)(&service->addr))->sun_path))
+		goto err;
+	close(cl_fd);
+
+	return true;
+err:
+	errno = save_errno;
+	close(cl_fd);
+	return false;
+}
+
 /** Try to bind and listen on the configured port.
  *
  * Throws an exception if error.
@@ -213,12 +239,18 @@ evio_service_bind_addr(struct evio_service *service)
 
 	evio_setsockopt_server(fd, service->addr.sa_family, SOCK_STREAM);
 
-	if (sio_bind(fd, &service->addr, service->addr_len) ||
-	    sio_listen(fd)) {
+	if (sio_bind(fd, &service->addr, service->addr_len)) {
 		assert(errno == EADDRINUSE);
-		close(fd);
+		if (!evio_service_reuse_addr(service) ||
+			sio_bind(fd, &service->addr, service->addr_len)) {
+			return -1;
+		}
+	}
+
+	if (sio_listen(fd)) {
 		return -1;
 	}
+
 	say_info("%s: bound to %s", evio_service_name(service),
 		 sio_strfaddr(&service->addr, service->addr_len));
 

test/box-tap/cfg.result

 TAP version 13
-1..39
+1..40
 ok - box is not started
 ok - invalid replication_source
 ok - invalid wal_mode
@@ -39,3 +39,4 @@ ok - logger_nonblock default value
 ok - logger_nonblock new value
 ok - dynamic listen
 ok - dynamic listen
+ok - reuse unix socket

test/box-tap/cfg.test.lua

@@ -4,7 +4,7 @@ local tap = require('tap')
 local test = tap.test('cfg')
 local socket = require('socket')
 local fio = require('fio')
-test:plan(39)
+test:plan(40)
 
 --------------------------------------------------------------------------------
 -- Invalid values
@@ -161,7 +161,7 @@ test:is(run_script(code), 0, "logger_nonblock new value")
 local path = './tarantool.sock'
 os.remove(path)
 box.cfg{ listen = 'unix/:'..path }
-s = socket.tcp_connect('unix/', path)
+local s = socket.tcp_connect('unix/', path)
 test:isnt(s, nil, "dynamic listen")
 if s then s:close() end
 box.cfg{ listen = '' }
@@ -170,5 +170,17 @@ test:isnil(s, 'dynamic listen')
 if s then s:close() end
 os.remove(path)
 
+path = './tarantool.sock'
+local path2 = './tarantool2.sock'
+local s = socket.tcp_server('unix/', path, function () end)
+os.execute('ln ' .. path .. ' ' .. path2)
+s:close()
+box.cfg{ listen = 'unix/:'.. path2}
+s = socket.tcp_connect('unix/', path2)
+test:isnt(s, nil, "reuse unix socket")
+if s then s:close() end
+box.cfg{ listen = '' }
+os.remove(path2)
+
 test:check()
 os.exit(0)