[Lldb-commits] [lldb] r230060 - Avoid a race condition when loading core files where the process might still be handling the eStateStopped event we post to the private state thread causing us to return from SBTarget::LoadCore() before the process is ready to have API calls used on it.

[Greg Clayton]

Author: gclayton
Date: Fri Feb 20 14:59:47 2015
New Revision: 230060

URL: http://llvm.org/viewvc/llvm-project?rev=230060&view=rev
Log:
Avoid a race condition when loading core files where the process might still be handling the eStateStopped event we post to the private state thread causing us to return from SBTarget::LoadCore() before the process is ready to have API calls used on it.

This fixes a crasher that could happen when loading core files from scripts.


Modified:
    lldb/trunk/source/Target/Process.cpp

Modified: lldb/trunk/source/Target/Process.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Target/Process.cpp?rev=230060&r1=230059&r2=230060&view=diff
==============================================================================
--- lldb/trunk/source/Target/Process.cpp (original)
+++ lldb/trunk/source/Target/Process.cpp Fri Feb 20 14:59:47 2015
@@ -3163,6 +3163,9 @@ Process::LoadCore ()
     Error error = DoLoadCore();
     if (error.Success())
     {
+        Listener listener ("lldb.process.load_core_listener");
+        HijackPrivateProcessEvents(&listener);
+
         if (PrivateStateThreadIsValid ())
             ResumePrivateStateThread ();
         else
@@ -3183,7 +3186,20 @@ Process::LoadCore ()
         // show all of the threads in the core file and explore the crashed
         // state.
         SetPrivateState (eStateStopped);
-        
+
+        // Wait indefinitely for a stopped event since we just posted one above...
+        lldb::EventSP event_sp;
+        listener.WaitForEvent (NULL, event_sp);
+        StateType state = ProcessEventData::GetStateFromEvent(event_sp.get());
+
+        if (!StateIsStoppedState (state, false))
+        {
+            Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
+            if (log)
+                log->Printf("Process::Halt() failed to stop, state is: %s", StateAsCString(state));
+            error.SetErrorString ("Did not get stopped event after loading the core file.");
+        }
+        RestorePrivateProcessEvents ();
     }
     return error;
 }