Merge pull request #11284 from ksooo/krypton-pvr-fix-thread-reusage-crash

[PVR] Krypton: Fix PVR Manager crash on startup

3 files changed, 13 insertions, 3 deletions

diff --git a/xbmc/pvr/PVRManager.cpp b/xbmc/pvr/PVRManager.cpp
index 66ec738383..aa0782102c 100644
--- a/xbmc/pvr/PVRManager.cpp
+++ b/xbmc/pvr/PVRManager.cpp
@@ -391,6 +391,12 @@ void CPVRManager::Reinit()
 
 void CPVRManager::Start()
 {
+  CSingleLock initLock(m_startStopMutex);
+
+  // Note: Stop() must not be called while holding pvr manager's mutex. Stop() calls
+  // StopThread() which can deadlock if the worker thread tries to acquire pvr manager's
+  // lock while StopThread() is waiting for the worker to exit. Thus, we introduce another
+  // lock here (m_startStopMutex), which only gets hold while starting/restarting pvr manager.
   Stop();
 
   CSingleLock lock(m_critSection);
@@ -412,8 +418,10 @@ void CPVRManager::Start()
 
 void CPVRManager::Stop(void)
 {
+  CSingleLock initLock(m_startStopMutex);
+
   /* check whether the pvrmanager is loaded */
-  if (IsStopping() || IsStopped())
+  if (IsStopped())
     return;
 
   SetState(ManagerStateStopping);
@@ -442,7 +450,7 @@ void CPVRManager::Stop(void)
 
   /* close database */
   const CPVRDatabasePtr database(GetTVDatabase());
-  if (database->IsOpen())
+  if (database && database->IsOpen())
     database->Close();
 
   SetState(ManagerStateStopped);
diff --git a/xbmc/pvr/PVRManager.h b/xbmc/pvr/PVRManager.h
index 05c30fc4b8..67c7c1fe18 100644
--- a/xbmc/pvr/PVRManager.h
+++ b/xbmc/pvr/PVRManager.h
@@ -706,6 +706,8 @@ private:
     ManagerState                    m_managerState;
     std::unique_ptr<CStopWatch>     m_parentalTimer;
 
+    CCriticalSection                m_startStopMutex; // mutex for protecting pvr manager's start/restart/stop sequence */
+
     std::atomic_bool m_isChannelPreview;
     CEventSource<PVREvent> m_events;
   };
diff --git a/xbmc/threads/Thread.cpp b/xbmc/threads/Thread.cpp
index ea03bb246d..b77ce8f90c 100644
--- a/xbmc/threads/Thread.cpp
+++ b/xbmc/threads/Thread.cpp
@@ -85,7 +85,7 @@ void CThread::Create(bool bAutoDelete, unsigned stacksize)
 {
   if (m_ThreadId != 0)
   {
-    LOG(LOGERROR, "%s - fatal error creating thread- old thread id not null", __FUNCTION__);
+    LOG(LOGERROR, "%s - fatal error creating thread %s - old thread id not null", __FUNCTION__, m_ThreadName.c_str());
     exit(1);
   }
   m_iLastTime = XbmcThreads::SystemClockMillis() * 10000;