Network: Use unique_ptr for packets, use deque for packet queues

src/network/core/packet.cpp

@@ -26,7 +26,6 @@ Packet::Packet(NetworkSocketHandler *cs)
 	assert(cs != nullptr);
 
 	this->cs     = cs;
-	this->next   = nullptr;
 	this->pos    = 0; // We start reading from here
 	this->size   = 0;
 	this->buffer = MallocT<byte>(SHRT_MAX);
@@ -53,7 +52,6 @@ Packet::~Packet()
 void Packet::ResetState(PacketType type)
 {
 	this->cs                   = nullptr;
-	this->next                 = nullptr;
 
 	/* Skip the size so we can write that in before sending the packet */
 	this->pos                  = 0;
@@ -66,7 +64,7 @@ void Packet::ResetState(PacketType type)
  */
 void Packet::PrepareToSend()
 {
-	assert(this->cs == nullptr && this->next == nullptr);
+	assert(this->cs == nullptr);
 
 	this->buffer[0] = GB(this->size, 0, 8);
 	this->buffer[1] = GB(this->size, 8, 8);
@@ -204,7 +202,7 @@ bool Packet::CanReadFromPacket(uint bytes_to_read, bool non_fatal)
  */
 void Packet::ReadRawPacketSize()
 {
-	assert(this->cs != nullptr && this->next == nullptr);
+	assert(this->cs != nullptr);
 	this->size  = (PacketSize)this->buffer[0];
 	this->size += (PacketSize)this->buffer[1] << 8;
 }

src/network/core/packet.h

@@ -39,8 +39,6 @@ typedef uint8  PacketType; ///< Identifier for the packet
  *     (year % 4 == 0) and ((year % 100 != 0) or (year % 400 == 0))
  */
 struct Packet {
-	/** The next packet. Used for queueing packets before sending. */
-	Packet *next;
 	/**
 	 * The size of the whole packet for received packets. For packets
 	 * that will be sent, the value is filled in just before the

src/network/core/tcp.cpp

@@ -22,7 +22,6 @@
  */
 NetworkTCPSocketHandler::NetworkTCPSocketHandler(SOCKET s) :
 		NetworkSocketHandler(),
-		packet_queue(nullptr), packet_recv(nullptr),
 		sock(s), writable(false)
 {
 }
@@ -41,13 +40,8 @@ NetworkRecvStatus NetworkTCPSocketHandler::CloseConnection(bool error)
 	NetworkSocketHandler::CloseConnection(error);
 
 	/* Free all pending and partially received packets */
-	while (this->packet_queue != nullptr) {
-		Packet *p = this->packet_queue->next;
-		delete this->packet_queue;
-		this->packet_queue = p;
-	}
-	delete this->packet_recv;
-	this->packet_recv = nullptr;
+	this->packet_queue.clear();
+	this->packet_recv.reset();
 
 	return NETWORK_RECV_STATUS_OKAY;
 }
@@ -58,9 +52,8 @@ NetworkRecvStatus NetworkTCPSocketHandler::CloseConnection(bool error)
  * if the OS-network-buffer is full)
  * @param packet the packet to send
  */
-void NetworkTCPSocketHandler::SendPacket(Packet *packet)
+void NetworkTCPSocketHandler::SendPacket(std::unique_ptr<Packet> packet)
 {
-	Packet *p;
 	assert(packet != nullptr);
 
 	packet->PrepareToSend();
@@ -70,16 +63,7 @@ void NetworkTCPSocketHandler::SendPacket(Packet *packet)
 	 * to do a denial of service attack! */
 	if (packet->size < ((SHRT_MAX * 2) / 3)) packet->buffer = ReallocT(packet->buffer, packet->size);
 
-	/* Locate last packet buffered for the client */
-	p = this->packet_queue;
-	if (p == nullptr) {
-		/* No packets yet */
-		this->packet_queue = packet;
-	} else {
-		/* Skip to the last packet */
-		while (p->next != nullptr) p = p->next;
-		p->next = packet;
-	}
+	this->packet_queue.push_back(std::move(packet));
 }
 
 /**
@@ -95,14 +79,13 @@ void NetworkTCPSocketHandler::SendPacket(Packet *packet)
 SendPacketsState NetworkTCPSocketHandler::SendPackets(bool closing_down)
 {
 	ssize_t res;
-	Packet *p;
 
 	/* We can not write to this socket!! */
 	if (!this->writable) return SPS_NONE_SENT;
 	if (!this->IsConnected()) return SPS_CLOSED;
 
-	p = this->packet_queue;
-	while (p != nullptr) {
+	while (!this->packet_queue.empty()) {
+		Packet *p = this->packet_queue.front().get();
 		res = send(this->sock, (const char*)p->buffer + p->pos, p->size - p->pos, 0);
 		if (res == -1) {
 			int err = GET_LAST_ERROR();
@@ -127,9 +110,7 @@ SendPacketsState NetworkTCPSocketHandler::SendPackets(bool closing_down)
 		/* Is this packet sent? */
 		if (p->pos == p->size) {
 			/* Go to the next packet */
-			this->packet_queue = p->next;
-			delete p;
-			p = this->packet_queue;
+			this->packet_queue.pop_front();
 		} else {
 			return SPS_PARTLY_SENT;
 		}
@@ -142,17 +123,17 @@ SendPacketsState NetworkTCPSocketHandler::SendPackets(bool closing_down)
  * Receives a packet for the given client
  * @return The received packet (or nullptr when it didn't receive one)
  */
-Packet *NetworkTCPSocketHandler::ReceivePacket()
+std::unique_ptr<Packet> NetworkTCPSocketHandler::ReceivePacket()
 {
 	ssize_t res;
 
 	if (!this->IsConnected()) return nullptr;
 
 	if (this->packet_recv == nullptr) {
-		this->packet_recv = new Packet(this);
+		this->packet_recv.reset(new Packet(this));
 	}
 
-	Packet *p = this->packet_recv;
+	Packet *p = this->packet_recv.get();
 
 	/* Read packet size */
 	if (p->pos < sizeof(PacketSize)) {
@@ -205,11 +186,11 @@ Packet *NetworkTCPSocketHandler::ReceivePacket()
 		p->pos += res;
 	}
 
-	/* Prepare for receiving a new packet */
-	this->packet_recv = nullptr;
 
 	p->PrepareToRead();
-	return p;
+
+	/* Prepare for receiving a new packet */
+	return std::move(this->packet_recv);
 }
 
 /**

src/network/core/tcp.h

@@ -15,6 +15,9 @@
 #include "address.h"
 #include "packet.h"
 
+#include <deque>
+#include <memory>
+
 /** The states of sending the packets. */
 enum SendPacketsState {
 	SPS_CLOSED,      ///< The connection got closed.
@@ -26,8 +29,8 @@ enum SendPacketsState {
 /** Base socket handler for all TCP sockets */
 class NetworkTCPSocketHandler : public NetworkSocketHandler {
 private:
-	Packet *packet_queue;     ///< Packets that are awaiting delivery
-	Packet *packet_recv;      ///< Partially received packet
+	std::deque<std::unique_ptr<Packet>> packet_queue; ///< Packets that are awaiting delivery
+	std::unique_ptr<Packet> packet_recv;              ///< Partially received packet
 public:
 	SOCKET sock;              ///< The socket currently connected to
 	bool writable;            ///< Can we write to this socket?
@@ -39,10 +42,16 @@ public:
 	bool IsConnected() const { return this->sock != INVALID_SOCKET; }
 
 	NetworkRecvStatus CloseConnection(bool error = true) override;
-	virtual void SendPacket(Packet *packet);
+	virtual void SendPacket(std::unique_ptr<Packet> packet);
+
+	void SendPacket(Packet *packet)
+	{
+		this->SendPacket(std::unique_ptr<Packet>(packet));
+	}
+
 	SendPacketsState SendPackets(bool closing_down = false);
 
-	virtual Packet *ReceivePacket();
+	virtual std::unique_ptr<Packet> ReceivePacket();
 
 	bool CanSendReceive();
 
@@ -50,7 +59,7 @@ public:
 	 * Whether there is something pending in the send queue.
 	 * @return true when something is pending in the send queue.
 	 */
-	bool HasSendQueue() { return this->packet_queue != nullptr; }
+	bool HasSendQueue() { return !this->packet_queue.empty(); }
 
 	NetworkTCPSocketHandler(SOCKET s = INVALID_SOCKET);
 	~NetworkTCPSocketHandler();

src/network/core/tcp_admin.cpp

@@ -112,9 +112,9 @@ NetworkRecvStatus NetworkAdminSocketHandler::HandlePacket(Packet *p)
  */
 NetworkRecvStatus NetworkAdminSocketHandler::ReceivePackets()
 {
-	Packet *p;
+	std::unique_ptr<Packet> p;
 	while ((p = this->ReceivePacket()) != nullptr) {
-		NetworkRecvStatus res = this->HandlePacket(p);
+		NetworkRecvStatus res = this->HandlePacket(p.get());
 		if (res != NETWORK_RECV_STATUS_OKAY) return res;
 	}
 

src/network/core/tcp_content.cpp

@@ -204,12 +204,11 @@ bool NetworkContentSocketHandler::ReceivePackets()
 	 *
 	 * What arbitrary number to choose is the ultimate question though.
 	 */
-	Packet *p;
+	std::unique_ptr<Packet> p;
 	static const int MAX_PACKETS_TO_RECEIVE = 42;
 	int i = MAX_PACKETS_TO_RECEIVE;
 	while (--i != 0 && (p = this->ReceivePacket()) != nullptr) {
-		bool cont = this->HandlePacket(p);
-		delete p;
+		bool cont = this->HandlePacket(p.get());
 		if (!cont) return true;
 	}
 

src/network/core/tcp_game.cpp

@@ -137,10 +137,9 @@ NetworkRecvStatus NetworkGameSocketHandler::HandlePacket(Packet *p)
  */
 NetworkRecvStatus NetworkGameSocketHandler::ReceivePackets()
 {
-	Packet *p;
+	std::unique_ptr<Packet> p;
 	while ((p = this->ReceivePacket()) != nullptr) {
-		NetworkRecvStatus res = HandlePacket(p);
-		delete p;
+		NetworkRecvStatus res = HandlePacket(p.get());
 		if (res != NETWORK_RECV_STATUS_OKAY) return res;
 	}
 

src/network/network_server.cpp

@@ -60,9 +60,9 @@ template SocketList TCPListenHandler<ServerNetworkGameSocketHandler, PACKET_SERV
 /** Writing a savegame directly to a number of packets. */
 struct PacketWriter : SaveFilter {
 	ServerNetworkGameSocketHandler *cs; ///< Socket we are associated with.
-	Packet *current;                    ///< The packet we're currently writing to.
+	std::unique_ptr<Packet> current;    ///< The packet we're currently writing to.
 	size_t total_size;                  ///< Total size of the compressed savegame.
-	Packet *packets;                    ///< Packet queue of the savegame; send these "slowly" to the client.
+	std::deque<std::unique_ptr<Packet>> packets; ///< Packet queue of the savegame; send these "slowly" to the client.
 	std::mutex mutex;                   ///< Mutex for making threaded saving safe.
 	std::condition_variable exit_sig;   ///< Signal for threaded destruction of this packet writer.
 
@@ -70,7 +70,7 @@ struct PacketWriter : SaveFilter {
 	 * Create the packet writer.
 	 * @param cs The socket handler we're making the packets for.
 	 */
-	PacketWriter(ServerNetworkGameSocketHandler *cs) : SaveFilter(nullptr), cs(cs), current(nullptr), total_size(0), packets(nullptr)
+	PacketWriter(ServerNetworkGameSocketHandler *cs) : SaveFilter(nullptr), cs(cs), total_size(0)
 	{
 	}
 
@@ -83,13 +83,8 @@ struct PacketWriter : SaveFilter {
 
 		/* This must all wait until the Destroy function is called. */
 
-		while (this->packets != nullptr) {
-			Packet *p = this->packets->next;
-			delete this->packets;
-			this->packets = p;
-		}
-
-		delete this->current;
+		this->packets.clear();
+		this->current.reset();
 	}
 
 	/**
@@ -129,21 +124,19 @@ struct PacketWriter : SaveFilter {
 	{
 		std::lock_guard<std::mutex> lock(this->mutex);
 
-		return this->packets != nullptr;
+		return !this->packets.empty();
 	}
 
 	/**
 	 * Pop a single created packet from the queue with packets.
 	 */
-	Packet *PopPacket()
+	std::unique_ptr<Packet> PopPacket()
 	{
 		std::lock_guard<std::mutex> lock(this->mutex);
 
-		Packet *p = this->packets;
-		if (p == nullptr) return nullptr;
-		this->packets = p->next;
-		p->next = nullptr;
-
+		if (this->packets.empty()) return nullptr;
+		std::unique_ptr<Packet> p = std::move(this->packets.front());
+		this->packets.pop_front();
 		return p;
 	}
 
@@ -152,13 +145,14 @@ struct PacketWriter : SaveFilter {
 	{
 		if (this->current == nullptr) return;
 
-		Packet **p = &this->packets;
-		while (*p != nullptr) {
-			p = &(*p)->next;
-		}
-		*p = this->current;
+		this->packets.push_back(std::move(this->current));
+	}
+
+	void PrependQueue(std::unique_ptr<Packet> p)
+	{
+		if (p == nullptr) return;
 
-		this->current = nullptr;
+		this->packets.push_front(std::move(p));
 	}
 
 	void Write(byte *buf, size_t size) override
@@ -166,7 +160,7 @@ struct PacketWriter : SaveFilter {
 		/* We want to abort the saving when the socket is closed. */
 		if (this->cs == nullptr) SlError(STR_NETWORK_ERROR_LOSTCONNECTION);
 
-		if (this->current == nullptr) this->current = new Packet(PACKET_SERVER_MAP_DATA);
+		if (this->current == nullptr) this->current.reset(new Packet(PACKET_SERVER_MAP_DATA));
 
 		std::lock_guard<std::mutex> lock(this->mutex);
 
@@ -179,7 +173,7 @@ struct PacketWriter : SaveFilter {
 
 			if (this->current->size == SHRT_MAX) {
 				this->AppendQueue();
-				if (buf != bufe) this->current = new Packet(PACKET_SERVER_MAP_DATA);
+				if (buf != bufe) this->current.reset(new Packet(PACKET_SERVER_MAP_DATA));
 			}
 		}
 
@@ -197,13 +191,13 @@ struct PacketWriter : SaveFilter {
 		this->AppendQueue();
 
 		/* Add a packet stating that this is the end to the queue. */
-		this->current = new Packet(PACKET_SERVER_MAP_DONE);
+		this->current.reset(new Packet(PACKET_SERVER_MAP_DONE));
 		this->AppendQueue();
 
 		/* Fast-track the size to the client. */
-		Packet *p = new Packet(PACKET_SERVER_MAP_SIZE);
+		std::unique_ptr<Packet> p(new Packet(PACKET_SERVER_MAP_SIZE));
 		p->Send_uint32((uint32)this->total_size);
-		this->cs->NetworkTCPSocketHandler::SendPacket(p);
+		this->PrependQueue(std::move(p));
 	}
 };
 
@@ -241,7 +235,7 @@ ServerNetworkGameSocketHandler::~ServerNetworkGameSocketHandler()
 	}
 }
 
-Packet *ServerNetworkGameSocketHandler::ReceivePacket()
+std::unique_ptr<Packet> ServerNetworkGameSocketHandler::ReceivePacket()
 {
 	/* Only allow receiving when we have some buffer free; this value
 	 * can go negative, but eventually it will become positive again. */
@@ -249,7 +243,7 @@ Packet *ServerNetworkGameSocketHandler::ReceivePacket()
 
 	/* We can receive a packet, so try that and if needed account for
 	 * the amount of received data. */
-	Packet *p = this->NetworkTCPSocketHandler::ReceivePacket();
+	std::unique_ptr<Packet> p = this->NetworkTCPSocketHandler::ReceivePacket();
 	if (p != nullptr) this->receive_limit -= p->size;
 	return p;
 }
@@ -627,14 +621,14 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendMap()
 		bool has_packets = true;
 
 		for (uint i = 0; i < sent_packets; i++) {
-			Packet *p = this->savegame->PopPacket();
+			std::unique_ptr<Packet> p = this->savegame->PopPacket();
 			if (p == nullptr) {
 				has_packets = false;
 				break;
 			}
 			last_packet = p->buffer[2] == PACKET_SERVER_MAP_DONE;
 
-			this->SendPacket(p);
+			this->SendPacket(std::move(p));
 
 			if (last_packet) {
 				/* There is no more data, so break the for */

src/network/network_server.h

@@ -85,7 +85,7 @@ public:
 	ServerNetworkGameSocketHandler(SOCKET s);
 	~ServerNetworkGameSocketHandler();
 
-	virtual Packet *ReceivePacket() override;
+	virtual std::unique_ptr<Packet> ReceivePacket() override;
 	NetworkRecvStatus CloseConnection(NetworkRecvStatus status) override;
 	void GetClientName(char *client_name, const char *last) const;