Trying to isolate the Win32 timeout.

Author: ashgti

lldb/tools/lldb-dap/DAP.cpp

@@ -256,7 +256,7 @@ void DAP::Send(const Message &message) {
   if (auto *resp = std::get_if<Response>(&message);
       resp && debugger.InterruptRequested()) {
     // If the debugger was interrupted, convert this response into a 'cancelled'
-    // response.
+    // response because we might have a partial result.
     Response cancelled = CancelledResponse(resp->request_seq, resp->command);
     if (llvm::Error err = transport.Write(cancelled))
       DAP_LOG_ERROR(log, std::move(err), "({1}) write failed: {0}",

lldb/tools/lldb-dap/Handler/CancelRequestHandler.cpp

@@ -43,7 +43,7 @@ namespace lldb_dap {
 /// The progress that got cancelled still needs to send a `progressEnd` event
 /// back.
 ///
-/// A client should not assume that progress just got cancelled after sending
+/// A client cannot assume that progress just got cancelled after sending
 /// the `cancel` request.
 llvm::Expected<CancelResponseBody>
 CancelRequestHandler::Run(const CancelArguments &arguments) const {

lldb/tools/lldb-dap/Transport.cpp

@@ -35,28 +35,29 @@ ReadFull(IOObject &descriptor, size_t length,
   if (!descriptor.IsValid())
     return createStringError("transport output is closed");
 
-  SelectHelper sh;
+  bool timeout_supported = true;
   // FIXME: SelectHelper does not work with NativeFile on Win32.
 #if _WIN32
-  if (timeout && descriptor.GetFdType() == eFDTypeSocket)
-    sh.SetTimeout(*timeout);
-#else
-  if (timeout)
-    sh.SetTimeout(*timeout);
+  timeout_supported = descriptor.GetFdType() == eFDTypeSocket;
 #endif
-  sh.FDSetRead(descriptor.GetWaitableHandle());
-  Status status = sh.Select();
-  if (status.Fail()) {
-    // Convert timeouts into a specific error.
-    if (status.GetType() == lldb::eErrorTypePOSIX &&
-        status.GetError() == ETIMEDOUT)
-      return make_error<TimeoutError>();
-    return status.takeError();
+
+  if (timeout && timeout_supported) {
+    SelectHelper sh;
+    sh.SetTimeout(*timeout);
+    sh.FDSetRead(descriptor.GetWaitableHandle());
+    Status status = sh.Select();
+    if (status.Fail()) {
+      // Convert timeouts into a specific error.
+      if (status.GetType() == lldb::eErrorTypePOSIX &&
+          status.GetError() == ETIMEDOUT)
+        return make_error<TimeoutError>();
+      return status.takeError();
+    }
   }
 
   std::string data;
   data.resize(length);
-  status = descriptor.Read(data.data(), length);
+  Status status = descriptor.Read(data.data(), length);
   if (status.Fail())
     return status.takeError();