Author: amccarth Date: Mon Jul 22 10:03:20 2019 New Revision: 366703 URL: http://llvm.org/viewvc/llvm-project?rev=366703&view=rev Log: [Windows] Fix race condition between state changes
Patch by Martin Andersson (martin.anders...@evoma.se) If the process is resumed before the state is changed to "running" there is a possibility (when single stepping) that the debugger stops and changes the state to "stopped" before it is first changed to "running". This causes the process to ignore the stop event (since the state did not change) which in turn leads the DebuggerThread to wait indefinitely for the exception predicate in HandleExceptionEvent. Differential Revision: https://reviews.llvm.org/D62183 Modified: lldb/trunk/source/Plugins/Process/Windows/Common/ProcessWindows.cpp Modified: lldb/trunk/source/Plugins/Process/Windows/Common/ProcessWindows.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/Windows/Common/ProcessWindows.cpp?rev=366703&r1=366702&r2=366703&view=diff ============================================================================== --- lldb/trunk/source/Plugins/Process/Windows/Common/ProcessWindows.cpp (original) +++ lldb/trunk/source/Plugins/Process/Windows/Common/ProcessWindows.cpp Mon Jul 22 10:03:20 2019 @@ -205,16 +205,6 @@ Status ProcessWindows::DoResume() { m_session_data->m_debugger->GetProcess().GetProcessId(), GetPrivateState()); - ExceptionRecordSP active_exception = - m_session_data->m_debugger->GetActiveException().lock(); - if (active_exception) { - // Resume the process and continue processing debug events. Mask the - // exception so that from the process's view, there is no indication that - // anything happened. - m_session_data->m_debugger->ContinueAsyncException( - ExceptionResult::MaskException); - } - LLDB_LOG(log, "resuming {0} threads.", m_thread_list.GetSize()); bool failed = false; @@ -233,10 +223,19 @@ Status ProcessWindows::DoResume() { if (failed) { error.SetErrorString("ProcessWindows::DoResume failed"); - return error; } else { SetPrivateState(eStateRunning); } + + ExceptionRecordSP active_exception = + m_session_data->m_debugger->GetActiveException().lock(); + if (active_exception) { + // Resume the process and continue processing debug events. Mask the + // exception so that from the process's view, there is no indication that + // anything happened. + m_session_data->m_debugger->ContinueAsyncException( + ExceptionResult::MaskException); + } } else { LLDB_LOG(log, "error: process {0} is in state {1}. Returning...", m_session_data->m_debugger->GetProcess().GetProcessId(), _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
