New try at recvmmsg with some improvements

src/base/system.c

@@ -1522,29 +1522,80 @@ int net_udp_send(NETSOCKET sock, const NETADDR *addr, const void *data, int size
 #endif /* FUZZING */
 }
 
-int net_udp_recv(NETSOCKET sock, NETADDR *addr, void *data, int maxsize)
+void net_init_mmsgs(MMSGS* m)
+{
+#if defined(CONF_PLATFORM_LINUX)
+	m->pos = 0;
+	m->size = 0;
+	mem_zero(m->msgs, sizeof(m->msgs));
+	mem_zero(m->iovecs, sizeof(m->iovecs));
+	mem_zero(m->sockaddrs, sizeof(m->sockaddrs));
+	for(int i = 0; i < VLEN; ++i)
+	{
+		m->iovecs[i].iov_base = m->bufs[i];
+		m->iovecs[i].iov_len = PACKETSIZE;
+		m->msgs[i].msg_hdr.msg_iov = &m->iovecs[i];
+		m->msgs[i].msg_hdr.msg_iovlen = 1;
+		m->msgs[i].msg_hdr.msg_name = &m->sockaddrs[i];
+		m->msgs[i].msg_hdr.msg_namelen = sizeof(&m->sockaddrs[i]);
+	}
+#endif
+}
+
+int net_udp_recv(NETSOCKET sock, NETADDR *addr, void *data, int maxsize, MMSGS* m)
 {
 #ifndef FUZZING
 	char sockaddrbuf[128];
-	socklen_t fromlen;// = sizeof(sockaddrbuf);
 	int bytes = 0;
 
+#if defined(CONF_PLATFORM_LINUX)
+	if(sock.ipv4sock >= 0)
+	{
+		if(m->pos >= m->size)
+		{
+			m->size = recvmmsg(sock.ipv4sock, m->msgs, VLEN, 0, NULL);
+			m->pos = 0;
+		}
+	}
+
+	if(sock.ipv6sock >= 0)
+	{
+		if(m->pos >= m->size)
+		{
+			m->size = recvmmsg(sock.ipv6sock, m->msgs, VLEN, 0, NULL);
+			m->pos = 0;
+		}
+	}
+
+	if(m->pos < m->size)
+	{
+		sockaddr_to_netaddr((struct sockaddr *)&(m->sockaddrs[m->pos]), addr);
+		// TODO: network_stats
+		//network_stats.recv_bytes += bytes;
+		//network_stats.recv_packets++;
+		bytes = m->msgs[m->pos].msg_len;
+		mem_copy(data, m->bufs[m->pos], bytes);
+		m->pos++;
+		return bytes;
+	}
+#else
 	if(bytes == 0 && sock.ipv4sock >= 0)
 	{
-		fromlen = sizeof(struct sockaddr_in);
+		int fromlen = sizeof(struct sockaddr_in);
 		bytes = recvfrom(sock.ipv4sock, (char*)data, maxsize, 0, (struct sockaddr *)&sockaddrbuf, &fromlen);
 	}
 
 	if(bytes <= 0 && sock.ipv6sock >= 0)
 	{
-		fromlen = sizeof(struct sockaddr_in6);
+		int fromlen = sizeof(struct sockaddr_in6);
 		bytes = recvfrom(sock.ipv6sock, (char*)data, maxsize, 0, (struct sockaddr *)&sockaddrbuf, &fromlen);
 	}
+#endif
 
 #if defined(CONF_WEBSOCKETS)
 	if(bytes <= 0 && sock.web_ipv4sock >= 0)
 	{
-		fromlen = sizeof(struct sockaddr);
+		int fromlen = sizeof(struct sockaddr);
 		bytes = websocket_recv(sock.web_ipv4sock, data, maxsize, (struct sockaddr_in *)&sockaddrbuf, fromlen);
 		((struct sockaddr_in *)&sockaddrbuf)->sin_family = AF_WEBSOCKET_INET;
 	}
@@ -1560,7 +1611,7 @@ int net_udp_recv(NETSOCKET sock, NETADDR *addr, void *data, int maxsize)
 	else if(bytes == 0)
 		return 0;
 	return -1; /* error */
-#else
+#else /* ifdef FUZZING */
 	addr->type = NETTYPE_IPV4;
 	addr->port = 11111;
 	addr->ip[0] = 127;

src/base/system.h

@@ -9,6 +9,11 @@
 #define BASE_SYSTEM_H
 
 #include "detect.h"
+
+#ifndef __USE_GNU
+#define __USE_GNU
+#endif
+
 #include <stddef.h>
 #include <stdlib.h>
 #include <time.h>
@@ -17,6 +22,10 @@
 #include <sys/un.h>
 #endif
 
+#ifdef CONF_PLATFORM_LINUX
+#include <sys/socket.h>
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -747,6 +756,22 @@ NETSOCKET net_udp_create(NETADDR bindaddr);
 */
 int net_udp_send(NETSOCKET sock, const NETADDR *addr, const void *data, int size);
 
+#define VLEN 128
+#define PACKETSIZE 1400
+typedef struct
+{
+#ifdef CONF_PLATFORM_LINUX
+	int pos;
+	int size;
+	struct mmsghdr msgs[VLEN];
+	struct iovec iovecs[VLEN];
+	char bufs[VLEN][PACKETSIZE];
+	char sockaddrs[VLEN][128];
+#endif
+} MMSGS;
+
+void net_init_mmsgs(MMSGS* m);
+
 /*
 	Function: net_udp_recv
 		Receives a packet over an UDP socket.
@@ -761,7 +786,7 @@ int net_udp_send(NETSOCKET sock, const NETADDR *addr, const void *data, int size
 		On success it returns the number of bytes received. Returns -1
 		on error.
 */
-int net_udp_recv(NETSOCKET sock, NETADDR *addr, void *data, int maxsize);
+int net_udp_recv(NETSOCKET sock, NETADDR *addr, void *data, int maxsize, MMSGS* m);
 
 /*
 	Function: net_udp_close

src/engine/server/server.cpp

@@ -2031,6 +2031,13 @@ int CServer::Run()
 				int64 t = time_get();
 				int x = (TickStartTime(m_CurrentGameTick+1) - t) * 1000000 / time_freq() + 1;
 
+				if(x > 3000)
+				{
+					// at least sleep 3 ms, reduce number of syscalls in stress situations
+					thread_sleep(3);
+					x = (TickStartTime(m_CurrentGameTick+1) - t) * 1000000 / time_freq() + 1;
+				}
+
 				if(x > 0)
 				{
 					net_socket_read_wait(m_NetServer.Socket(), x);

src/engine/shared/network.h

@@ -301,6 +301,7 @@ class CNetServer
 	};
 
 	NETSOCKET m_Socket;
+	MMSGS m_MMSGS;
 	class CNetBan *m_pNetBan;
 	CSlot m_aSlots[NET_MAX_CLIENTS];
 	int m_MaxClients;
@@ -423,6 +424,7 @@ class CNetClient
 	CNetRecvUnpacker m_RecvUnpacker;
 public:
 	NETSOCKET m_Socket;
+	MMSGS m_MMSGS;
 	// openness
 	bool Open(NETADDR BindAddr, int Flags);
 	int Close();

src/engine/shared/network_client.cpp

@@ -17,6 +17,8 @@ bool CNetClient::Open(NETADDR BindAddr, int Flags)
 	// init
 	m_Socket = Socket;
 	m_Connection.Init(m_Socket, false);
+	net_init_mmsgs(&m_MMSGS);
+
 	return true;
 }
 
@@ -64,7 +66,7 @@ int CNetClient::Recv(CNetChunk *pChunk)
 
 		// TODO: empty the recvinfo
 		NETADDR Addr;
-		int Bytes = net_udp_recv(m_Socket, &Addr, m_RecvUnpacker.m_aBuffer, NET_MAX_PACKETSIZE);
+		int Bytes = net_udp_recv(m_Socket, &Addr, m_RecvUnpacker.m_aBuffer, NET_MAX_PACKETSIZE, &m_MMSGS);
 
 		// no more packets for now
 		if(Bytes <= 0)

src/engine/shared/network_server.cpp

@@ -80,6 +80,8 @@ bool CNetServer::Open(NETADDR BindAddr, CNetBan *pNetBan, int MaxClients, int Ma
 	for(int i = 0; i < NET_MAX_CLIENTS; i++)
 		m_aSlots[i].m_Connection.Init(m_Socket, true);
 
+	net_init_mmsgs(&m_MMSGS);
+
 	return true;
 }
 
@@ -598,7 +600,7 @@ int CNetServer::Recv(CNetChunk *pChunk)
 			return 1;
 
 		// TODO: empty the recvinfo
-		int Bytes = net_udp_recv(m_Socket, &Addr, m_RecvUnpacker.m_aBuffer, NET_MAX_PACKETSIZE);
+		int Bytes = net_udp_recv(m_Socket, &Addr, m_RecvUnpacker.m_aBuffer, NET_MAX_PACKETSIZE, &m_MMSGS);
 
 		// no more packets for now
 		if(Bytes <= 0)