Ticket #5604: DeviceReadBuffer-polltimeout.2.patch

libs/libmythtv/DeviceReadBuffer.h

@@ -59 +59 @@
     void IncrReadPointer(uint len);
 
     bool HandlePausing(void);
-    bool Poll(void) const;
+    bool Poll(void);
     uint WaitForUnused(uint bytes_needed) const;
     uint WaitForUsed  (uint bytes_needed) const;
 

libs/libmythtv/DeviceReadBuffer.cpp

@@ -90 +90 @@
 
 void DeviceReadBuffer::Start(void)
 {
-    lock.lock();
-    bool was_running = running;
-    lock.unlock();
+    bool was_running;
+
+    {
+        QMutexLocker locker(&lock);
+        was_running = running;
+        error = false;
+    }
+
     if (was_running)
     {
         VERBOSE(VB_IMPORTANT, LOC_ERR + "Start(): Already running.");
@@ -104 +109 @@
     {
         VERBOSE(VB_IMPORTANT,
                 LOC_ERR + QString("Start(): pthread_create failed.") + ENO);
+
+        QMutexLocker locker(&lock);
         error = true;
     }
 }
@@ -118 +125 @@
     used          = 0;
     readPtr       = buffer;
     writePtr      = buffer;
+
+    error         = false;
 }
 
 void DeviceReadBuffer::Stop(void)
 {
     bool was_running = IsRunning();
-    lock.lock();
-    run = false;
-    lock.unlock();
 
     if (!was_running)
     {
-        VERBOSE(VB_IMPORTANT, LOC_ERR + "Stop(): Not running.");
+        VERBOSE(VB_IMPORTANT, LOC + "Stop(): Not running.");
         return;
     }
 
+    {
+        QMutexLocker locker(&lock);
+        run = false;
+    }
+
     pthread_join(thread, NULL);
 }
 
@@ -229 +240 @@
 {
     uint      errcnt = 0;
 
-    lock.lock();
-    run     = true;
-    running = true;
-    lock.unlock();
+    {
+        QMutexLocker locker(&lock);
+        run     = true;
+        running = true;
+    }
 
     while (run)
     {
@@ -248 +260 @@
         if (using_poll && !Poll())
             continue;
 
+        {
+            QMutexLocker locker(&lock);
+            if (error)
+            {
+                VERBOSE(VB_RECORD, LOC + "fill_ringbuffer: error state");
+                break;
+            }
+        }
+
         // Limit read size for faster return from read
         size_t read_size =
             min(dev_read_size, (size_t) WaitForUnused(TSPacket::SIZE));
@@ -268 +289 @@
         }
     }
 
-    lock.lock();
-    running = false;
-    lock.unlock();
+    {
+        QMutexLocker locker(&lock);
+        running = false;
+    }
 }
 
 bool DeviceReadBuffer::HandlePausing(void)
@@ -293 +315 @@
     return true;
 }
 
-bool DeviceReadBuffer::Poll(void) const
+bool DeviceReadBuffer::Poll(void)
 {
 #ifdef USING_MINGW
 #warning mingw DeviceReadBuffer::Poll
@@ -302 +324 @@
     return false;
 #else
     bool retval = true;
-    while (true)
+    uint timeout_cnt = 0;
+
+    for (;;)
     {
         struct pollfd polls;
         polls.fd      = _stream_fd;
         polls.events  = POLLIN;
         polls.revents = 0;
 
-        int ret = poll(&polls, 1 /*number of polls*/, 10 /*msec*/);
-        if (IsPauseRequested() || !IsOpen() || !run)
+        int ret = poll(&polls, 1 /*number of polls*/, 250 /*msec*/);
+
+        if (polls.revents & (POLLERR | POLLHUP | POLLNVAL))
         {
+            VERBOSE(VB_IMPORTANT, LOC + "poll error");
+            error = true;
+            return true;
+        }
+
+        if (!run || !IsOpen() || IsPauseRequested())
+        {
             retval = false;
             break; // are we supposed to pause, stop, etc.
         }
 
         if (ret > 0)
             break; // we have data to read :)
-        if ((-1 == ret) && (EOVERFLOW == errno))
-            break; // we have an error to handle
-
-        if ((-1 == ret) && ((EAGAIN == errno) || (EINTR  == errno)))
-            continue; // errors that tell you to try again
-        if (ret == 0)
-            continue; // timed out, try again
-
-        usleep(2500);
+        if (ret < 0)
+        {
+            if ((EOVERFLOW == errno))
+                break; // we have an error to handle
+            if ((EAGAIN == errno) || (EINTR  == errno))
+                continue; // errors that tell you to try again
+            usleep(2500);
+        }
+        else //  ret == 0
+        {
+            if (++timeout_cnt > 9)
+            {
+                VERBOSE(VB_RECORD, LOC_ERR + "Poll giving up");
+                QMutexLocker locker(&lock);
+                error = true;
+                return true;
+            }
+            if (timeout_cnt % 2)
+                VERBOSE(VB_RECORD, LOC_ERR + QString("Poll timeout (%1)")
+                        .arg(timeout_cnt));
+        }
     }
     return retval;
 #endif //!USING_MINGW
@@ -360 +404 @@
 
         if (++errcnt > 5)
         {
-            lock.lock();
+            QMutexLocker locker(&lock);
+            VERBOSE(VB_RECORD, LOC + "Too many errors.");
             error = true;
-            lock.unlock();
             return false;
         }
 
@@ -376 +420 @@
             VERBOSE(VB_IMPORTANT, LOC +
                     QString("End-Of-File? fd(%1)").arg(_stream_fd));
 
-            lock.lock();
+            QMutexLocker locker(&lock);
             eof = true;
-            lock.unlock();
-
             return false;
         }
         usleep(500);