[llvm] [llvm][Support] Improvements to raw_socket_stream functionality and documentation (PR #84710)

[Michael Spencer via llvm-commits]

================
@@ -58,11 +59,80 @@ TEST(raw_socket_streamTest, CLIENT_TO_SERVER_AND_SERVER_TO_CLIENT) {
   Client << "01234567";
   Client.flush();
 
+  char Bytes[8];
   ssize_t BytesRead = Server.read(Bytes, 8);
 
   std::string string(Bytes, 8);
 
   ASSERT_EQ(8, BytesRead);
   ASSERT_EQ("01234567", string);
 }
-} // namespace
\ No newline at end of file
+
+TEST(raw_socket_streamTest, TIMEOUT_PROVIDED) {
+  if (!hasUnixSocketSupport())
+    GTEST_SKIP();
+
+  SmallString<100> SocketPath;
+  llvm::sys::fs::createUniquePath("timout_provided.sock", SocketPath, true);
+
+  // Make sure socket file does not exist. May still be there from the last test
+  std::remove(SocketPath.c_str());
+
+  Expected<ListeningSocket> MaybeServerListener =
+      ListeningSocket::createUnix(SocketPath);
+  ASSERT_THAT_EXPECTED(MaybeServerListener, llvm::Succeeded());
+  ListeningSocket ServerListener = std::move(*MaybeServerListener);
+
+  std::chrono::milliseconds Timeout = std::chrono::milliseconds(100);
+  auto Start = std::chrono::steady_clock::now();
+  Expected<std::unique_ptr<raw_socket_stream>> MaybeServer =
+      ServerListener.accept(Timeout);
+  auto End = std::chrono::steady_clock::now();
+  auto Duration =
+      std::chrono::duration_cast<std::chrono::milliseconds>(End - Start);
+  ASSERT_NEAR(Duration.count(), Timeout.count(), 10);
+
+  ASSERT_THAT_EXPECTED(MaybeServer, Failed());
+  llvm::Error Err = MaybeServer.takeError();
+  llvm::handleAllErrors(std::move(Err), [&](const llvm::StringError &SE) {
+    std::error_code EC = SE.convertToErrorCode();
+    ASSERT_EQ(EC, std::errc::timed_out);
+  });
+}
+
+TEST(raw_socket_streamTest, FILE_DESCRIPTOR_CLOSED) {
+  if (!hasUnixSocketSupport())
+    GTEST_SKIP();
+
+  SmallString<100> SocketPath;
+  llvm::sys::fs::createUniquePath("fd_closed.sock", SocketPath, true);
+
+  // Make sure socket file does not exist. May still be there from the last test
+  std::remove(SocketPath.c_str());
+
+  Expected<ListeningSocket> MaybeServerListener =
+      ListeningSocket::createUnix(SocketPath);
+  ASSERT_THAT_EXPECTED(MaybeServerListener, llvm::Succeeded());
+  ListeningSocket ServerListener = std::move(*MaybeServerListener);
+
+  // Create a separate thread to close the socket after a delay. Simulates a
+  // signal handler calling ServerListener::shutdown
+  std::thread CloseThread([&]() {
+    std::this_thread::sleep_for(std::chrono::seconds(2));
----------------
Bigcheese wrote:

Use a shorter time to reduce test run length.

https://github.com/llvm/llvm-project/pull/84710