Make networkDataPerSocketRead mode the highest priority mode

Summary:
networkDataPerSocketRead has other impacts on behavior beyond the read function being used. It affects how reads and write loopers are updated.

When this option is turned on, its read function must be the highest priority otherwise any other reader will stall and stop reading packets.

Differential Revision: D66888140

fbshipit-source-id: 630dbbf51b02bac2f22f1ece534ad60cf61d88ea

quic/client/QuicClientTransport.cpp

@@ -1692,14 +1692,14 @@ void QuicClientTransport::onNotifyDataAvailable(
       ? conn_->transportSettings.readCoalescingSize
       : readBufferSize;
 
-  if (conn_->transportSettings.shouldUseRecvfromForBatchRecv) {
-    readWithRecvfrom(sock, readAllocSize, numPackets);
+  if (conn_->transportSettings.networkDataPerSocketRead) {
+    readWithRecvmsgSinglePacketLoop(sock, readAllocSize);
   } else if (conn_->transportSettings.shouldUseWrapperRecvmmsgForBatchRecv) {
     readWithRecvmmsgWrapper(sock, readAllocSize, numPackets);
   } else if (conn_->transportSettings.shouldUseRecvmmsgForBatchRecv) {
     readWithRecvmmsg(sock, readAllocSize, numPackets);
-  } else if (conn_->transportSettings.networkDataPerSocketRead) {
-    readWithRecvmsgSinglePacketLoop(sock, readAllocSize);
+  } else if (conn_->transportSettings.shouldUseRecvfromForBatchRecv) {
+    readWithRecvfrom(sock, readAllocSize, numPackets);
   } else {
     readWithRecvmsg(sock, readAllocSize, numPackets);
   }