Change the Mutex::Locker class so that it takes the Mutex object and locks it, rather

than being given the pthread_mutex_t from the Mutex and locks that.  That allows us to
track ownership of the Mutex better.  

Used this to switch the LLDB_CONFIGURATION_DEBUG enabled assert when we can't get the
gdb-remote sequence mutex to assert when the thread that had the mutex releases it.  This
is generally more useful information than saying just who failed to get it (since the
code that had it locked often had released it by the time the assert fired.)

llvm-svn: 158240

5 files changed, 16 insertions, 32 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
index fc83724fb25..0712ed4e1f7 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
@@ -263,10 +263,10 @@ GDBRemoteCommunication::GetAck ()
 }
 
 bool
-GDBRemoteCommunication::GetSequenceMutex (Mutex::Locker& locker)
+GDBRemoteCommunication::GetSequenceMutex (Mutex::Locker& locker, const char *failure_message)
 {
     if (IsRunning())
-        return locker.TryLock (m_sequence_mutex);
+        return locker.TryLock (m_sequence_mutex, failure_message);
 
     locker.Lock (m_sequence_mutex);
     return true;
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h
index b3bad7ede5c..a1077957c6a 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h
@@ -59,7 +59,7 @@ public:
                         size_t payload_length);
 
     bool
-    GetSequenceMutex (lldb_private::Mutex::Locker& locker);
+    GetSequenceMutex (lldb_private::Mutex::Locker& locker, const char *failure_message = NULL);
 
     bool
     CheckForPacket (const uint8_t *src, 
@@ -242,7 +242,11 @@ protected:
     // Classes that inherit from GDBRemoteCommunication can see and modify these
     //------------------------------------------------------------------
     uint32_t m_packet_timeout;
+#ifdef LLDB_CONFIGURATION_DEBUG
+    lldb_private::TrackingMutex m_sequence_mutex;
+#else
     lldb_private::Mutex m_sequence_mutex;    // Restrict access to sending/receiving packets to a single thread at a time
+#endif
     lldb_private::Predicate<bool> m_public_is_running;
     lldb_private::Predicate<bool> m_private_is_running;
     History m_history;
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index 90fb47eb7a3..b08350a5ec8 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -1939,7 +1939,7 @@ GDBRemoteCommunicationClient::GetCurrentThreadIDs (std::vector<lldb::tid_t> &thr
     Mutex::Locker locker;
     thread_ids.clear();
     
-    if (GetSequenceMutex (locker))
+    if (GetSequenceMutex (locker, "ProcessGDBRemote::UpdateThreadList() failed due to not getting the sequence mutex"))
     {
         sequence_mutex_unavailable = false;
         StringExtractorGDBRemote response;
@@ -1968,9 +1968,13 @@ GDBRemoteCommunicationClient::GetCurrentThreadIDs (std::vector<lldb::tid_t> &thr
     }
     else
     {
+#if defined (LLDB_CONFIGURATION_DEBUG)
+        // assert(!"ProcessGDBRemote::UpdateThreadList() failed due to not getting the sequence mutex");
+#else
         LogSP log (ProcessGDBRemoteLog::GetLogIfAnyCategoryIsSet (GDBR_LOG_PROCESS | GDBR_LOG_PACKETS));
         if (log)
             log->Printf("error: failed to get packet sequence mutex, not sending packet 'qfThreadInfo'");
+#endif
         sequence_mutex_unavailable = true;
     }
     return thread_ids.size();
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
index 9eec09d0b5c..4247add8554 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
@@ -183,7 +183,7 @@ GDBRemoteRegisterContext::ReadRegisterBytes (const RegisterInfo *reg_info, DataE
     if (!m_reg_valid[reg])
     {
         Mutex::Locker locker;
-        if (gdb_comm.GetSequenceMutex (locker))
+        if (gdb_comm.GetSequenceMutex (locker, "Didn't get sequence mutex for read register."))
         {
             const bool thread_suffix_supported = gdb_comm.GetThreadSuffixSupported();
             ProcessSP process_sp (m_thread.GetProcess());
@@ -357,7 +357,7 @@ GDBRemoteRegisterContext::WriteRegisterBytes (const lldb_private::RegisterInfo *
                                   m_reg_data.GetByteOrder()))   // dst byte order
     {
         Mutex::Locker locker;
-        if (gdb_comm.GetSequenceMutex (locker))
+        if (gdb_comm.GetSequenceMutex (locker, "Didn't get sequence mutex for write register."))
         {
             const bool thread_suffix_supported = gdb_comm.GetThreadSuffixSupported();
             ProcessSP process_sp (m_thread.GetProcess());
@@ -445,12 +445,6 @@ GDBRemoteRegisterContext::WriteRegisterBytes (const lldb_private::RegisterInfo *
         else
         {
             LogSP log (ProcessGDBRemoteLog::GetLogIfAnyCategoryIsSet (GDBR_LOG_THREAD | GDBR_LOG_PACKETS));
-#if LLDB_CONFIGURATION_DEBUG
-            StreamString strm;
-            gdb_comm.DumpHistory(strm);
-            Host::SetCrashDescription (strm.GetData());
-            assert (!"Didn't get sequence mutex for write register.");
-#else
             if (log)
             {
                 if (log->GetVerbose())
@@ -462,7 +456,6 @@ GDBRemoteRegisterContext::WriteRegisterBytes (const lldb_private::RegisterInfo *
                 else
                     log->Printf("error: failed to get packet sequence mutex, not sending write register for \"%s\"", reg_info->name);
             }
-#endif
         }
     }
     return false;
@@ -484,7 +477,7 @@ GDBRemoteRegisterContext::ReadAllRegisterValues (lldb::DataBufferSP &data_sp)
     StringExtractorGDBRemote response;
 
     Mutex::Locker locker;
-    if (gdb_comm.GetSequenceMutex (locker))
+    if (gdb_comm.GetSequenceMutex (locker, "Didn't get sequence mutex for read all registers."))
     {
         char packet[32];
         const bool thread_suffix_supported = gdb_comm.GetThreadSuffixSupported();
@@ -522,12 +515,6 @@ GDBRemoteRegisterContext::ReadAllRegisterValues (lldb::DataBufferSP &data_sp)
     else
     {
         LogSP log (ProcessGDBRemoteLog::GetLogIfAnyCategoryIsSet (GDBR_LOG_THREAD | GDBR_LOG_PACKETS));
-#if LLDB_CONFIGURATION_DEBUG
-        StreamString strm;
-        gdb_comm.DumpHistory(strm);
-        Host::SetCrashDescription (strm.GetData());
-        assert (!"Didn't get sequence mutex for read all registers.");
-#else
         if (log)
         {
             if (log->GetVerbose())
@@ -539,7 +526,6 @@ GDBRemoteRegisterContext::ReadAllRegisterValues (lldb::DataBufferSP &data_sp)
             else
                 log->Printf("error: failed to get packet sequence mutex, not sending read all registers");
         }
-#endif
     }
 
     data_sp.reset();
@@ -563,7 +549,7 @@ GDBRemoteRegisterContext::WriteAllRegisterValues (const lldb::DataBufferSP &data
 
     StringExtractorGDBRemote response;
     Mutex::Locker locker;
-    if (gdb_comm.GetSequenceMutex (locker))
+    if (gdb_comm.GetSequenceMutex (locker, "Didn't get sequence mutex for write all registers."))
     {
         const bool thread_suffix_supported = gdb_comm.GetThreadSuffixSupported();
         ProcessSP process_sp (m_thread.GetProcess());
@@ -662,12 +648,6 @@ GDBRemoteRegisterContext::WriteAllRegisterValues (const lldb::DataBufferSP &data
     else
     {
         LogSP log (ProcessGDBRemoteLog::GetLogIfAnyCategoryIsSet (GDBR_LOG_THREAD | GDBR_LOG_PACKETS));
-#if LLDB_CONFIGURATION_DEBUG
-        StreamString strm;
-        gdb_comm.DumpHistory(strm);
-        Host::SetCrashDescription (strm.GetData());
-        assert (!"Didn't get sequence mutex for write all registers.");
-#else
         if (log)
         {
             if (log->GetVerbose())
@@ -679,7 +659,6 @@ GDBRemoteRegisterContext::WriteAllRegisterValues (const lldb::DataBufferSP &data
             else
                 log->Printf("error: failed to get packet sequence mutex, not sending write all registers");
         }
-#endif
     }
     return false;
 }
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index be5ccab7b90..ed826bac7c2 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -1190,9 +1190,6 @@ ProcessGDBRemote::UpdateThreadIDList ()
     m_gdb_comm.GetCurrentThreadIDs (m_thread_ids, sequence_mutex_unavailable);
     if (sequence_mutex_unavailable)
     {
-#if defined (LLDB_CONFIGURATION_DEBUG)
-        assert(!"ProcessGDBRemote::UpdateThreadList() failed due to not getting the sequence mutex");
-#endif
         return false; // We just didn't get the list
     }
     return true;