fix(test): close TSAN race in WaitForSocketFile helper

score/datarouter/test/ut/ut_logging/test_unix_domain_server.cpp

@@ -270,18 +270,27 @@ UnixDomainSockAddr MakeTempAddrAbstractFalse(std::string& name)
     return UnixDomainSockAddr(name, /*isAbstract=*/false);
 }
 
-/// Block until the filesystem socket at \p path exists (i.e. bind() completed).
+/// Block until the server at \p path is accepting connections (i.e. listen() completed).
+/// A successful non-blocking connect() proves the server passed both bind() and listen().
 /// Returns true on success, false on timeout.
 bool WaitForSocketFile(const std::string& path, std::chrono::milliseconds timeout = std::chrono::milliseconds(5000))
 {
     constexpr auto kPollInterval = std::chrono::milliseconds(10);
     auto deadline = std::chrono::steady_clock::now() + timeout;
     while (std::chrono::steady_clock::now() < deadline)
     {
-        struct stat st{};
-        if (::stat(path.c_str(), &st) == 0 && (st.st_mode & S_IFSOCK) != 0)
+        int fd = ::socket(AF_UNIX, SOCK_STREAM, 0);
+        if (fd >= 0)
         {
-            return true;
+            sockaddr_un su{};
+            su.sun_family = AF_UNIX;
+            std::strncpy(su.sun_path, path.c_str(), sizeof(su.sun_path) - 1);
+            if (::connect(fd, reinterpret_cast<sockaddr*>(&su), sizeof(su)) == 0)
+            {
+                ::close(fd);
+                return true;
+            }
+            ::close(fd);
         }
         std::this_thread::sleep_for(kPollInterval);
     }