[Lldb-commits] [lldb] r249206 - Have a clean(er) shutdown when detaching from a process.

[Zachary Turner via lldb-commits]

Author: zturner
Date: Fri Oct  2 17:47:04 2015
New Revision: 249206

URL: http://llvm.org/viewvc/llvm-project?rev=249206&view=rev
Log:
Have a clean(er) shutdown when detaching from a process.

Modified:
    lldb/trunk/source/Plugins/Process/Windows/Live/DebuggerThread.cpp

Modified: lldb/trunk/source/Plugins/Process/Windows/Live/DebuggerThread.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/Windows/Live/DebuggerThread.cpp?rev=249206&r1=249205&r2=249206&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/Windows/Live/DebuggerThread.cpp (original)
+++ lldb/trunk/source/Plugins/Process/Windows/Live/DebuggerThread.cpp Fri Oct  2 17:47:04 2015
@@ -304,20 +304,13 @@ DebuggerThread::DebugLoop()
             {
                 case EXCEPTION_DEBUG_EVENT:
                 {
-                    if (m_is_shutting_down)
-                    {
-                        // Don't perform any blocking operations while we're shutting down.  That will
-                        // cause TerminateProcess -> WaitForSingleObject to time out.
-                        continue_status = DBG_EXCEPTION_NOT_HANDLED;
-                        break;
-                    }
-
                     ExceptionResult status = HandleExceptionEvent(dbe.u.Exception, dbe.dwThreadId);
 
                     if (status == ExceptionResult::MaskException)
                         continue_status = DBG_CONTINUE;
                     else if (status == ExceptionResult::SendToApplication)
                         continue_status = DBG_EXCEPTION_NOT_HANDLED;
+
                     break;
                 }
                 case CREATE_THREAD_DEBUG_EVENT:
@@ -377,6 +370,24 @@ DebuggerThread::DebugLoop()
 ExceptionResult
 DebuggerThread::HandleExceptionEvent(const EXCEPTION_DEBUG_INFO &info, DWORD thread_id)
 {
+    if (m_is_shutting_down)
+    {
+        // A breakpoint that occurs while `m_pid_to_detach` is non-zero is a magic exception that
+        // we use simply to wake up the DebuggerThread so that we can close out the debug loop.
+        if (m_pid_to_detach != 0 && info.ExceptionRecord.ExceptionCode == EXCEPTION_BREAKPOINT)
+        {
+            WINLOG_IFANY(WINDOWS_LOG_EVENT | WINDOWS_LOG_EXCEPTION | WINDOWS_LOG_PROCESS,
+                            "Breakpoint exception is cue to detach from process 0x%x",
+                            m_pid_to_detach);
+            ::DebugActiveProcessStop(m_pid_to_detach);
+            m_detached = true;
+        }
+
+        // Don't perform any blocking operations while we're shutting down.  That will
+        // cause TerminateProcess -> WaitForSingleObject to time out.
+        return ExceptionResult::SendToApplication;
+    }
+
     bool first_chance = (info.dwFirstChance != 0);
 
     m_active_exception.reset(new ExceptionRecord(info.ExceptionRecord, thread_id));
@@ -384,18 +395,6 @@ DebuggerThread::HandleExceptionEvent(con
                  "HandleExceptionEvent encountered %s chance exception 0x%x on thread 0x%x",
                  first_chance ? "first" : "second", info.ExceptionRecord.ExceptionCode, thread_id);
 
-    if (m_pid_to_detach != 0 && m_active_exception->GetExceptionCode() == EXCEPTION_BREAKPOINT) {
-        WINLOG_IFANY(WINDOWS_LOG_EVENT | WINDOWS_LOG_EXCEPTION | WINDOWS_LOG_PROCESS,
-                     "Breakpoint exception is cue to detach from process 0x%x",
-                     m_pid_to_detach);
-        if (::DebugActiveProcessStop(m_pid_to_detach)) {
-            m_detached = true;
-            return ExceptionResult::MaskException;
-        } else {
-            WINLOG_IFANY(WINDOWS_LOG_PROCESS, "Failed to detach, treating as a regular breakpoint");
-        }
-    }
-
     ExceptionResult result = m_debug_delegate->OnDebugException(first_chance,
                                                                 *m_active_exception);
     m_exception_pred.SetValue(result, eBroadcastNever);