Convert the DVB Stream Read thread to QThread

Pursuant to #5501, I have converted the DVB Stream Read thread from pthreads
to QThread.  The startup synchronization here was a bit excessive, and has been
simplified.

This has been successfully recording from my DVB capture devices (ATSC to be
exact) for most oF a week.

mythtv/libs/libmythtv/dvbstreamhandler.cpp

@@ -1,7 +1,6 @@
 // -*- Mode: c++ -*-
 
 // POSIX headers
-#include <pthread.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <sys/select.h>
@@ -95,8 +94,6 @@ DVBStreamHandler::DVBStreamHandler(const QString &dvb_device) :
     _allow_retune(false),
 
     _start_stop_lock(QMutex::Recursive),
-    _running(false),
-    _reader_thread(pthread_t()),
     _using_section_reader(false),
 
     _device_read_buffer(NULL),
@@ -188,11 +185,12 @@ void DVBStreamHandler::RemoveListener(MPEGStreamData *data)
     VERBOSE(VB_RECORD, LOC + "RemoveListener("<<data<<") -- end");
 }
 
-void *run_dvb_stream_handler_thunk(void *param)
+void DVBReadThread::run(void)
 {
-    DVBStreamHandler *mon = (DVBStreamHandler*) param;
-    mon->Run();
-    return NULL;
+    if (!m_parent)
+        return;
+
+    m_parent->Run();
 }
 
 void DVBStreamHandler::Start(void)
@@ -209,22 +207,14 @@ void DVBStreamHandler::Start(void)
 
     if (!IsRunning())
     {
-        QMutex is_running_lock;
-        int rval = pthread_create(&_reader_thread, NULL,
-                                  run_dvb_stream_handler_thunk, this);
+        _reader_thread.SetParent(this);
+        _reader_thread.start();
 
-        if (0 != rval)
+        if (_reader_thread.isRunning())
         {
-            VERBOSE(VB_IMPORTANT, LOC_ERR +
-                    "Start: Failed to create thread." + ENO);
+            VERBOSE(VB_IMPORTANT, LOC_ERR + "Start: Failed to create thread.");
             return;
         }
-
-        is_running_lock.lock();
-        while (!IsRunning())
-        {
-            _running_state_changed.wait(&is_running_lock, 100);
-        }
     }
 }
 
@@ -236,15 +226,12 @@ void DVBStreamHandler::Stop(void)
     {
         if (_device_read_buffer)
             _device_read_buffer->Stop();
-        SetRunning(false);
-        pthread_join(_reader_thread, NULL);
+        _reader_thread.wait();
     }
 }
 
 void DVBStreamHandler::Run(void)
 {
-    SetRunning(true);
-
     _using_section_reader = !SupportsTSMonitoring() && _allow_section_reader;
 
     if (_using_section_reader)
@@ -407,8 +394,6 @@ void DVBStreamHandler::RunTS(void)
     delete[] buffer;
 
     VERBOSE(VB_RECORD, LOC + "RunTS(): " + "end");
-
-    SetRunning(false);
 }
 
 /** \fn DVBStreamHandler::RunSR(void)
@@ -990,12 +975,6 @@ bool PIDInfo::Close(const QString &dvb_dev)
     return true;
 }
 
-void DVBStreamHandler::SetRunning(bool is_running)
-{
-    _running = is_running;
-    _running_state_changed.wakeAll();
-}
-
 PIDPriority DVBStreamHandler::GetPIDPriority(uint pid) const
 {
     QMutexLocker reading_locker(&_listener_lock);

mythtv/libs/libmythtv/dvbstreamhandler.h

@@ -8,6 +8,7 @@ using namespace std;
 
 #include <QMap>
 #include <QMutex>
+#include <QThread>
 
 #include "util.h"
 #include "DeviceReadBuffer.h"
@@ -45,9 +46,20 @@ class PIDInfo
 };
 typedef QMap<uint,PIDInfo*> PIDInfoMap;
 
+class DVBReadThread : public QThread
+{
+    Q_OBJECT
+  public:
+    DVBReadThread() : m_parent(NULL) {}
+    void SetParent(DVBStreamHandler *parent) { m_parent = parent; }
+    void run(void);
+  private:
+    DVBStreamHandler *m_parent;
+};
+
 class DVBStreamHandler : public ReaderPausedCB
 {
-    friend void *run_dvb_stream_handler_thunk(void *param);
+    friend class DVBReadThread;
 
   public:
     static DVBStreamHandler *Get(const QString &dvb_device);
@@ -60,7 +72,7 @@ class DVBStreamHandler : public ReaderPausedCB
 
     void RetuneMonitor(void);
 
-    bool IsRunning(void) const { return _running; }
+    bool IsRunning(void) const { return _reader_thread.isRunning(); }
     bool IsRetuneAllowed(void) const { return _allow_retune; }
 
     void SetRetuneAllowed(bool              allow,
@@ -88,8 +100,6 @@ class DVBStreamHandler : public ReaderPausedCB
     bool RemoveAllPIDFilters(void);
     void CycleFiltersByPriority(void);
 
-    void SetRunning(bool);
-
     PIDPriority GetPIDPriority(uint pid) const;
     bool SupportsTSMonitoring(void);
 
@@ -101,9 +111,7 @@ class DVBStreamHandler : public ReaderPausedCB
     bool              _allow_retune;
 
     mutable QMutex     _start_stop_lock;
-    bool              _running;
-    QWaitCondition    _running_state_changed;
-    pthread_t         _reader_thread;
+    DVBReadThread     _reader_thread;
     bool              _using_section_reader;
     DeviceReadBuffer *_device_read_buffer;
     DTVSignalMonitor *_sigmon;