PktSrc iosource changes to match the new IOSource API

src/iosource/PktSrc.cc

@@ -109,9 +109,20 @@ void PktSrc::Opened(const Properties& arg_props)
 		return;
 		}
 
+
 	if ( props.is_live )
+		{
 		Info(fmt("listening on %s\n", props.path.c_str()));
 
+		// We only register the file descriptor if we're in live
+		// mode because libpcap's file descriptor for trace files
+		// isn't a reliable way to know whether we actually have
+		// data to read.
+		if ( props.selectable_fd != -1 )
+			if ( ! iosource_mgr->RegisterFd(props.selectable_fd, this) )
+				reporter->FatalError("Failed to register pktsrc fd with iosource_mgr");
+		}
+
 	DBG_LOG(DBG_PKTIO, "Opened source %s", props.path.c_str());
 	}
 
@@ -119,6 +130,9 @@ void PktSrc::Closed()
 	{
 	SetClosed(true);
 
+	if ( props.is_live && props.selectable_fd != -1 )
+		iosource_mgr->UnregisterFd(props.selectable_fd, this);
+
 	DBG_LOG(DBG_PKTIO, "Closed source %s", props.path.c_str());
 	}
 
@@ -166,7 +180,7 @@ double PktSrc::CheckPseudoTime()
 	return pseudo_time <= ct ? bro_start_time + pseudo_time : 0;
 	}
 
-void PktSrc::Init()
+void PktSrc::InitSource()
 	{
 	Open();
 	}
@@ -177,55 +191,6 @@ void PktSrc::Done()
 		Close();
 	}
 
-void PktSrc::GetFds(iosource::FD_Set* read, iosource::FD_Set* write,
-                    iosource::FD_Set* except)
-	{
-	if ( pseudo_realtime )
-		{
-		// Select would give erroneous results. But we simulate it
-		// by setting idle accordingly.
-		SetIdle(CheckPseudoTime() == 0);
-		return;
-		}
-
-	if ( IsOpen() && props.selectable_fd >= 0 )
-		read->Insert(props.selectable_fd);
-
-	// TODO: This seems like a hack that should be removed, but doing so
-	// causes the main run loop to spin more frequently and increase cpu usage.
-	// See also commit 9cd85be308.
-	if ( read->Empty() )
-		read->Insert(0);
-
-	if ( write->Empty() )
-		write->Insert(0);
-
-	if ( except->Empty() )
-		except->Insert(0);
-	}
-
-double PktSrc::NextTimestamp(double* local_network_time)
-	{
-	if ( ! IsOpen() )
-		return -1.0;
-
-	if ( ! ExtractNextPacketInternal() )
-		return -1.0;
-
-	if ( pseudo_realtime )
-		{
-		// Delay packet if necessary.
-		double packet_time = CheckPseudoTime();
-		if ( packet_time )
-			return packet_time;
-
-		SetIdle(true);
-		return -1.0;
-		}
-
-	return current_packet.time;
-	}
-
 void PktSrc::Process()
 	{
 	if ( ! IsOpen() )
@@ -248,7 +213,7 @@ void PktSrc::Process()
 			net_packet_dispatch(current_packet.time, &current_packet, this);
 		}
 
-	have_packet = 0;
+	have_packet = false;
 	DoneWithPacket();
 	}
 
@@ -267,10 +232,7 @@ bool PktSrc::ExtractNextPacketInternal()
 	// Don't return any packets if processing is suspended (except for the
 	// very first packet which we need to set up times).
 	if ( net_is_processing_suspended() && first_timestamp )
-		{
-		SetIdle(true);
-		return 0;
-		}
+		return false;
 
 	if ( pseudo_realtime )
 		current_wallclock = current_time(true);
@@ -280,15 +242,14 @@ bool PktSrc::ExtractNextPacketInternal()
 		if ( current_packet.time < 0 )
 			{
 			Weird("negative_packet_timestamp", &current_packet);
-			return 0;
+			return false;
 			}
 
 		if ( ! first_timestamp )
 			first_timestamp = current_packet.time;
 
-		SetIdle(false);
 		have_packet = true;
-		return 1;
+		return true;
 		}
 
 	if ( pseudo_realtime && ! IsOpen() )
@@ -297,8 +258,7 @@ bool PktSrc::ExtractNextPacketInternal()
 			iosource_mgr->Terminate();
 		}
 
-	SetIdle(true);
-	return 0;
+	return false;
 	}
 
 bool PktSrc::PrecompileBPFFilter(int index, const std::string& filter)
@@ -321,7 +281,7 @@ bool PktSrc::PrecompileBPFFilter(int index, const std::string& filter)
 		Error(msg);
 
 		delete code;
-		return 0;
+		return false;
 		}
 
 	// Store it in vector.
@@ -369,3 +329,30 @@ bool PktSrc::GetCurrentPacket(const Packet** pkt)
 	*pkt = &current_packet;
 	return true;
 	}
+
+double PktSrc::GetNextTimeout()
+	{
+	// If there's no file descriptor for the source, which is the case for some interfaces like
+	// myricom, we can't rely on the polling mechanism to wait for data to be available. As gross
+	// as it is, just spin with a short timeout here so that it will continually poll the
+	// interface. The old IOSource code had a 20ns timeout between calls to select() so just
+	// use that.
+	if ( props.selectable_fd == -1 )
+		return 0.00000002;
+
+	// If we're live we want poll to do what it has to with the file descriptor. If we're not live
+	// but we're not in pseudo-realtime mode, let the loop just spin as fast as it can. If we're
+	// in pseudo-realtime mode, find the next time that a packet is ready and have poll block until
+	// then.
+	if ( IsLive() || net_is_processing_suspended() )
+		return -1;
+	else if ( ! pseudo_realtime )
+		return 0;
+
+	if ( ! have_packet )
+		ExtractNextPacketInternal();
+
+	double pseudo_time = current_packet.time - first_timestamp;
+	double ct = (current_time(true) - first_wallclock) * pseudo_realtime;
+	return std::max(0.0, pseudo_time - ct);
+	}

src/iosource/PktSrc.h

@@ -204,6 +204,17 @@ public:
 	 */
 	virtual void Statistics(Stats* stats) = 0;
 
+	/**
+	 * Return the next timeout value for this source. This should be
+	 * overridden by source classes where they have a timeout value
+	 * that can wake up the poll.
+	 *
+	 * @return A value for the next time that the source thinks the
+	 * poll should time out in seconds from the current time. Return
+	 * -1 if this should should not be considered.
+	 */
+	virtual double GetNextTimeout() override;
+
 protected:
 	friend class Manager;
 	friend class ManagerBase;
@@ -343,11 +354,8 @@ private:
 	bool ExtractNextPacketInternal();
 
 	// IOSource interface implementation.
-	void Init() override;
+	void InitSource() override;
 	void Done() override;
-	void GetFds(iosource::FD_Set* read, iosource::FD_Set* write,
-	                    iosource::FD_Set* except) override;
-	double NextTimestamp(double* local_network_time) override;
 	void Process() override;
 	const char* Tag() override;