Fix iohandler prompt race condition.

This issue caused the lldb prompt to not show up in certain cases, very
noticeable on Linux systems.

See details on this review:
http://reviews.llvm.org/D4863

And on this lldb-commits thread:
http://lists.cs.uiuc.edu/pipermail/lldb-commits/Week-of-Mon-20140811/012306.html

Change by Shawn Best.

(Much useful help and testing by the rest of the community, thanks all!)

llvm-svn: 215446

1 files changed, 5 insertions, 1 deletions

diff --git a/lldb/source/Commands/CommandObjectThread.cpp b/lldb/source/Commands/CommandObjectThread.cpp
index c58e9e83503..e7a8652ac89 100644
--- a/lldb/source/Commands/CommandObjectThread.cpp
+++ b/lldb/source/Commands/CommandObjectThread.cpp
@@ -624,7 +624,11 @@ protected:
 
             process->GetThreadList().SetSelectedThreadByID (thread->GetID());
             process->Resume ();
-        
+
+            // There is a race condition where this thread will return up the call stack to the main command handler
+            // and show an (lldb) prompt before HandlePrivateEvent (from PrivateStateThread) has
+            // a chance to call PushProcessIOHandler().
+            process->SyncIOHandler(2000);
 
             if (synchronous_execution)
             {