Fix on Linux for ReadThread lingering after inferior exits

See this email thread:
http://lists.cs.uiuc.edu/pipermail/lldb-commits/Week-of-Mon-20140818/012487.html

This patch handles the case where the inferior process exits but leaves the ReadThread in a continuous loop reading from the communication pipe.  On MacOSX, the ReadThread exits when it receives a 0 return value from the read due to EOF.  On Linux the read returns -1 and sets errno to EIO error, this does not currently cause the thread to shutdown so it continues to read from the comm.   In Communication::ReadThread I added a handler for eConnectionStatusError to disconnect and shutdown the thread.

Change by Alex Pepper.

llvm-svn: 216194

1 files changed, 13 insertions, 2 deletions

diff --git a/lldb/source/Core/Communication.cpp b/lldb/source/Core/Communication.cpp
index 20231c4506b..d71c9881a6f 100644
--- a/lldb/source/Core/Communication.cpp
+++ b/lldb/source/Core/Communication.cpp
@@ -380,13 +380,24 @@ Communication::ReadThread (lldb::thread_arg_t p)
             if (comm->GetCloseOnEOF())
                  done = true;
              break;
+        case eConnectionStatusError:            // Check GetError() for details
+            if (error.GetType() == eErrorTypePOSIX && error.GetError() == EIO)
+            {
+                // EIO on a pipe is usually caused by remote shutdown
+                comm->Disconnect ();
+                done = true;
+            }
+            if (log)
+                error.LogIfError (log,
+                                  "%p Communication::ReadFromConnection () => status = %s",
+                                  p,
+                                  Communication::ConnectionStatusAsCString (status));
+            break;
         case eConnectionStatusNoConnection:     // No connection
         case eConnectionStatusLostConnection:   // Lost connection while connected to a valid connection
         case eConnectionStatusInterrupted:      // Interrupted
-
             done = true;
             // Fall through...
-        case eConnectionStatusError:            // Check GetError() for details
         case eConnectionStatusTimedOut:         // Request timed out
             if (log)
                 error.LogIfError (log,