From cdb0e0ef215dbdfb1843045ab68f1523b8ac139f Mon Sep 17 00:00:00 2001
From: "[CST] Focus" <focus.cst@gmail.com>
Date: Mon, 12 Aug 2013 16:05:20 +0400
Subject: [PATCH] driver/record.cpp, driver/scanepg.cpp, zapit/src/zapit.cpp:
 try to prevent race while lock/allocate frontend in case of possible
 concurrent usage in neutrino and zapit threads

---
 src/driver/record.cpp   |  4 ++++
 src/driver/scanepg.cpp  |  6 ++++--
 src/zapit/src/zapit.cpp | 31 +++++++++++++++++++------------
 3 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/src/driver/record.cpp b/src/driver/record.cpp
index 123d6d012..d6bfd4398 100644
--- a/src/driver/record.cpp
+++ b/src/driver/record.cpp
@@ -1621,6 +1621,8 @@ bool CRecordManager::CutBackNeutrino(const t_channel_id channel_id, CFrontend *
 	if(live_channel_id != channel_id) {
 		/* first try to get frontend for record with locked live */
 		bool unlock = true;
+		/* executed in neutrino thread - possible race with zap NOWAIT and epg scan zap */
+		CFEManager::getInstance()->Lock();
 		CFEManager::getInstance()->lockFrontend(live_fe);
 		frontend = CFEManager::getInstance()->allocateFE(channel, true);
 		if (frontend == NULL) {
@@ -1629,6 +1631,8 @@ bool CRecordManager::CutBackNeutrino(const t_channel_id channel_id, CFrontend *
 			CFEManager::getInstance()->unlockFrontend(live_fe);
 			frontend = CFEManager::getInstance()->allocateFE(channel, true);
 		}
+		CFEManager::getInstance()->Unlock();
+
 		if (frontend == NULL)
 			return false;
 
diff --git a/src/driver/scanepg.cpp b/src/driver/scanepg.cpp
index 5bbf95ef7..b0e2075d5 100644
--- a/src/driver/scanepg.cpp
+++ b/src/driver/scanepg.cpp
@@ -129,10 +129,11 @@ void CEpgScan::Next()
 
 	t_channel_id live_channel_id = CZapit::getInstance()->GetCurrentChannelID();
 
-	CFrontend *live_fe = CZapit::getInstance()->GetLiveFrontend();
 	/* executed in neutrino thread - possible race with locks in zapit zap NOWAIT :
-	   send zaTo_NOWAIT -> EIT_COMPLETE from sectionsd -> zap and this at the same time
+	   send zapTo_NOWAIT -> EIT_COMPLETE from sectionsd -> zap and this at the same time
 	*/
+	CFEManager::getInstance()->Lock();
+	CFrontend *live_fe = CZapit::getInstance()->GetLiveFrontend();
 	CFEManager::getInstance()->lockFrontend(live_fe);
 #ifdef ENABLE_PIP
 	CFrontend *pip_fe = CZapit::getInstance()->GetPipFrontend();
@@ -158,6 +159,7 @@ void CEpgScan::Next()
 	if (pip_fe && pip_fe != live_fe)
 		CFEManager::getInstance()->unlockFrontend(pip_fe);
 #endif
+	CFEManager::getInstance()->Unlock();
 	if (next_chid)
 		g_Zapit->zapTo_epg(next_chid);
 }
diff --git a/src/zapit/src/zapit.cpp b/src/zapit/src/zapit.cpp
index 01447934f..373a371c8 100644
--- a/src/zapit/src/zapit.cpp
+++ b/src/zapit/src/zapit.cpp
@@ -483,6 +483,8 @@ bool CZapit::ZapIt(const t_channel_id channel_id, bool forupdate, bool startplay
 	INFO("[zapit] zap to %s (%" PRIx64 " tp %" PRIx64 ")", newchannel->getName().c_str(), newchannel->getChannelID(), newchannel->getTransponderId());
 
 #ifdef ENABLE_PIP
+	/* executed async if zap NOWAIT, race possible with record lock/allocate */
+	CFEManager::getInstance()->Lock();
 	if (pip_fe)
 		CFEManager::getInstance()->lockFrontend(pip_fe);
 	CFrontend * fe = CFEManager::getInstance()->allocateFE(newchannel);
@@ -492,6 +494,7 @@ bool CZapit::ZapIt(const t_channel_id channel_id, bool forupdate, bool startplay
 		StopPip();
 		fe = CFEManager::getInstance()->allocateFE(newchannel);
 	}
+	CFEManager::getInstance()->Unlock();
 #else
 	CFrontend * fe = CFEManager::getInstance()->allocateFE(newchannel);
 #endif
@@ -681,7 +684,6 @@ bool CZapit::ZapForEpg(const t_channel_id channel_id)
 {
 	CZapitChannel* newchannel;
 	bool transponder_change;
-	bool ret = false;
 
 	if((newchannel = CServiceManager::getInstance()->FindChannel(channel_id)) == NULL) {
 		INFO("channel_id " PRINTF_CHANNEL_ID_TYPE " not found", channel_id);
@@ -689,29 +691,34 @@ bool CZapit::ZapForEpg(const t_channel_id channel_id)
 	}
 	INFO("%s: %s (%" PRIx64 ")", __FUNCTION__, newchannel->getName().c_str(), channel_id);
 
+	/* executed async in zapit thread, race possible with record lock/allocate */
+	CFEManager::getInstance()->Lock();
+
 	CFEManager::getInstance()->lockFrontend(live_fe);
 #ifdef ENABLE_PIP
 	if (pip_fe && pip_fe != live_fe)
 		CFEManager::getInstance()->lockFrontend(pip_fe);
 #endif
 	CFrontend * frontend = CFEManager::getInstance()->allocateFE(newchannel);
-	if(frontend == NULL) {
-		ERROR("Cannot get frontend\n");
-		goto __error;
-	}
-	if(!TuneChannel(frontend, newchannel, transponder_change))
-		goto __error;
 
-	if(ParsePatPmt(newchannel))
-		ret = true;
-
-__error:
 	CFEManager::getInstance()->unlockFrontend(live_fe);
 #ifdef ENABLE_PIP
 	if (pip_fe && pip_fe != live_fe)
 		CFEManager::getInstance()->unlockFrontend(pip_fe);
 #endif
-	return ret;
+	CFEManager::getInstance()->Unlock();
+
+	if(frontend == NULL) {
+		ERROR("Cannot get frontend\n");
+		return false;
+	}
+	if(!TuneChannel(frontend, newchannel, transponder_change))
+		return false;
+
+	if(!ParsePatPmt(newchannel))
+		return false;
+
+	return true;
 }
 
 /* set channel/pid volume percent, using current channel_id and pid, if those params is 0 */