From f3fe1e9a136cb82f0683a41d6889acaf8cacff50 Mon Sep 17 00:00:00 2001
From: Rolf Ahrenberg <Rolf.Ahrenberg@sci.fi>
Date: Mon, 13 Nov 2017 22:12:10 +0200
Subject: [PATCH] Serialize channel switching to prevent device allocation
 failures.

---
 device.c   | 16 +++++++++++++++-
 device.h   |  8 +++++---
 deviceif.h |  1 +
 tuner.c    |  1 +
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/device.c b/device.c
index ee8c1c5..ddd5b55 100644
--- a/device.c
+++ b/device.c
@@ -15,6 +15,8 @@
 
 static cSatipDevice * SatipDevicesS[SATIP_MAX_DEVICES] = { NULL };
 
+cMutex cSatipDevice::mutexS = cMutex();
+
 cSatipDevice::cSatipDevice(unsigned int indexP)
 : deviceIndexM(indexP),
   isPacketDeliveredM(false),
@@ -22,7 +24,7 @@ cSatipDevice::cSatipDevice(unsigned int indexP)
   deviceNameM(*cString::sprintf("%s %d", *DeviceType(), deviceIndexM)),
   channelM(),
   createdM(0),
-  mutexM()
+  tunedM()
 {
   unsigned int bufsize = (unsigned int)SATIP_BUFFER_SIZE;
   bufsize -= (bufsize % TS_SIZE);
@@ -42,6 +44,8 @@ cSatipDevice::cSatipDevice(unsigned int indexP)
 cSatipDevice::~cSatipDevice()
 {
   debug1("%s [device %u]", __PRETTY_FUNCTION__, deviceIndexM);
+  // Release immediately any pending conditional wait
+  tunedM.Broadcast();
   // Stop section handler
   StopSectionHandler();
   DELETE_POINTER(pSectionFilterHandlerM);
@@ -339,6 +343,7 @@ bool cSatipDevice::MaySwitchTransponder(const cChannel *channelP) const
 
 bool cSatipDevice::SetChannelDevice(const cChannel *channelP, bool liveViewP)
 {
+  cMutexLock MutexLock(&mutexS);  // Global lock to prevent any simultaneous zapping
   debug9("%s (%d, %d) [device %u]", __PRETTY_FUNCTION__, channelP ? channelP->Number() : -1, liveViewP, deviceIndexM);
   if (channelP) {
      cDvbTransponderParameters dtp(channelP->Parameters());
@@ -356,6 +361,8 @@ bool cSatipDevice::SetChannelDevice(const cChannel *channelP, bool liveViewP)
      if (pTunerM && pTunerM->SetSource(server, channelP->Transponder(), *params, deviceIndexM)) {
         channelM = *channelP;
         deviceNameM = cString::sprintf("%s %d %s", *DeviceType(), deviceIndexM, *cSatipDiscover::GetInstance()->GetServerString(server));
+        // Wait for actual channel tuning to prevent simultaneous frontend allocation failures
+        tunedM.TimedWait(mutexS, eTuningTimeoutMs);
         return true;
         }
      }
@@ -367,6 +374,13 @@ bool cSatipDevice::SetChannelDevice(const cChannel *channelP, bool liveViewP)
   return false;
 }
 
+void cSatipDevice::SetChannelTuned(void)
+{
+  debug9("%s () [device %u]", __PRETTY_FUNCTION__, deviceIndexM);
+  // Release immediately any pending conditional wait
+  tunedM.Broadcast();
+}
+
 bool cSatipDevice::SetPid(cPidHandle *handleP, int typeP, bool onP)
 {
   debug12("%s (%d, %d, %d) [device %u]", __PRETTY_FUNCTION__, handleP ? handleP->pid : -1, typeP, onP, deviceIndexM);
diff --git a/device.h b/device.h
index 983e24d..334ceef 100644
--- a/device.h
+++ b/device.h
@@ -18,7 +18,7 @@
 class cSatipDevice : public cDevice, public cSatipPidStatistics, public cSatipBufferStatistics, public cSatipDeviceIf {
   // static ones
 public:
-  static unsigned int deviceCount;
+  static cMutex mutexS;
   static bool Initialize(unsigned int DeviceCount);
   static void Shutdown(void);
   static unsigned int Count(void);
@@ -28,7 +28,8 @@ public:
   // private parts
 private:
   enum {
-    eReadyTimeoutMs = 2000 // in milliseconds
+    eReadyTimeoutMs  = 2000, // in milliseconds
+    eTuningTimeoutMs = 1000  // in milliseconds
   };
   unsigned int deviceIndexM;
   bool isPacketDeliveredM;
@@ -39,7 +40,7 @@ private:
   cSatipTuner *pTunerM;
   cSatipSectionFilterHandler *pSectionFilterHandlerM;
   cTimeMs createdM;
-  cMutex mutexM;
+  cCondVar tunedM;
 
   // constructor & destructor
 public:
@@ -107,6 +108,7 @@ public:
   // for internal device interface
 public:
   virtual void WriteData(u_char *bufferP, int lengthP);
+  virtual void SetChannelTuned(void);
   virtual int GetId(void);
   virtual int GetPmtPid(void);
   virtual int GetCISlot(void);
diff --git a/deviceif.h b/deviceif.h
index 9fe1636..e0a418f 100644
--- a/deviceif.h
+++ b/deviceif.h
@@ -13,6 +13,7 @@ public:
   cSatipDeviceIf() {}
   virtual ~cSatipDeviceIf() {}
   virtual void WriteData(u_char *bufferP, int lengthP) = 0;
+  virtual void SetChannelTuned(void) = 0;
   virtual int GetId(void) = 0;
   virtual int GetPmtPid(void) = 0;
   virtual int GetCISlot(void) = 0;
diff --git a/tuner.c b/tuner.c
index 9eb1e06..df8aee9 100644
--- a/tuner.c
+++ b/tuner.c
@@ -126,6 +126,7 @@ void cSatipTuner::Action(void)
                break;
           case tsTuned:
                debug4("%s: tsTuned [device %d]", __PRETTY_FUNCTION__, deviceIdM);
+               deviceM->SetChannelTuned();
                reConnectM.Set(eConnectTimeoutMs);
                idleCheck.Set(eIdleCheckTimeoutMs);
                lastIdleStatus = false;