Author: abidh Date: Wed Feb 4 03:59:23 2015 New Revision: 228128 URL: http://llvm.org/viewvc/llvm-project?rev=228128&view=rev Log: Fix a race condition in lldb-mi.
lldb-mi has 3 threads. 1. One that waits for user intput. 2. Another waits for 1st thread to get input command. 3. Waits for events from lldb. 2 & 3 needs to be synchronized so that they don't end up doing things at same time. For example, while "break insert" is processing, we can get a breakpoint event. Depending on where we are in "break-insert", it can have different behavior. In some cases, it can cause breakpoint to be deleted too. I have added a mutex so that command processing and event processing are done exclusively and they are not running at the same time. In longer term, I think thread 2 & 3 should be merged to be only one thread which can wait on command or events. Reviewed in http://reviews.llvm.org/D7371. Modified: lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfo.h lldb/trunk/tools/lldb-mi/MICmnLLDBDebugger.cpp lldb/trunk/tools/lldb-mi/MIDriver.cpp Modified: lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfo.h URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfo.h?rev=228128&r1=228127&r2=228128&view=diff ============================================================================== --- lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfo.h (original) +++ lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfo.h Wed Feb 4 03:59:23 2015 @@ -35,6 +35,7 @@ #include "MICmnLLDBDebugSessionInfoVarObj.h" #include "MICmnMIValueTuple.h" #include "MIUtilMapIdToVariant.h" +#include "MIUtilThreadBaseStd.h" // Declarations: class CMICmnLLDBDebugger; @@ -156,6 +157,7 @@ class CMICmnLLDBDebugSessionInfo : publi bool RecordBrkPtInfo(const MIuint vnBrkPtId, const SBrkPtInfo &vrBrkPtInfo); bool RecordBrkPtInfoGet(const MIuint vnBrkPtId, SBrkPtInfo &vrwBrkPtInfo) const; bool RecordBrkPtInfoDelete(const MIuint vnBrkPtId); + CMIUtilThreadMutex& GetSessionMutex() { return m_sessionMutex;} lldb::SBDebugger &GetDebugger() const; lldb::SBListener &GetListener() const; lldb::SBTarget GetTarget() const; @@ -200,6 +202,7 @@ class CMICmnLLDBDebugSessionInfo : publi CMIUtilMapIdToVariant m_mapIdToSessionData; // Hold and retrieve key to value data available across all commands VecVarObj_t m_vecVarObj; // Vector of session variable objects MapBrkPtIdToBrkPtInfo_t m_mapBrkPtIdToBrkPtInfo; + CMIUtilThreadMutex m_sessionMutex; }; //++ ------------------------------------------------------------------------------------ Modified: lldb/trunk/tools/lldb-mi/MICmnLLDBDebugger.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/lldb-mi/MICmnLLDBDebugger.cpp?rev=228128&r1=228127&r2=228128&view=diff ============================================================================== --- lldb/trunk/tools/lldb-mi/MICmnLLDBDebugger.cpp (original) +++ lldb/trunk/tools/lldb-mi/MICmnLLDBDebugger.cpp Wed Feb 4 03:59:23 2015 @@ -664,7 +664,13 @@ CMICmnLLDBDebugger::MonitorSBListenerEve bool bHandledEvent = false; bool bExitAppEvent = false; - const bool bOk = CMICmnLLDBDebuggerHandleEvents::Instance().HandleEvent(event, bHandledEvent, bExitAppEvent); + + bool bOk = false; + { + // Lock Mutex before handling events so that we don't disturb a running cmd + CMIUtilThreadLock lock(CMICmnLLDBDebugSessionInfo::Instance().GetSessionMutex()); + bOk = CMICmnLLDBDebuggerHandleEvents::Instance().HandleEvent(event, bHandledEvent, bExitAppEvent); + } if (!bHandledEvent) { const CMIUtilString msg(CMIUtilString::Format(MIRSRC(IDS_LLDBDEBUGGER_WRN_UNKNOWN_EVENT), event.GetBroadcasterClass())); Modified: lldb/trunk/tools/lldb-mi/MIDriver.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/lldb-mi/MIDriver.cpp?rev=228128&r1=228127&r2=228128&view=diff ============================================================================== --- lldb/trunk/tools/lldb-mi/MIDriver.cpp (original) +++ lldb/trunk/tools/lldb-mi/MIDriver.cpp Wed Feb 4 03:59:23 2015 @@ -41,6 +41,7 @@ #include "MICmdArgValFile.h" #include "MICmdArgValString.h" #include "MICmnConfig.h" +#include "MICmnLLDBDebugSessionInfo.h" // Instantiations: #if _DEBUG @@ -687,7 +688,13 @@ CMIDriver::ReadStdinLineQueue(void) } // Process the command - const bool bOk = InterpretCommand(lineText); + bool bOk = false; + { + // Lock Mutex before processing commands so that we don't disturb an event + // that is being processed. + CMIUtilThreadLock lock(CMICmnLLDBDebugSessionInfo::Instance().GetSessionMutex()); + bOk = InterpretCommand(lineText); + } // Draw prompt if desired if (bOk && m_rStdin.GetEnablePrompt()) _______________________________________________ lldb-commits mailing list lldb-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/lldb-commits
