ServerLoop.pas

   1 UNIT ServerLoop;
   2
   3 INTERFACE
   4 uses MemStream,NetAddr,UnixType;
   5
   6 procedure Main;
   7
   8 {#Message handling#}
   9 type tSMsg=object
  10  Source: ^tNetAddr;
  11  Length: {Long}Word;
  12  Data: pointer;
  13  stream: tMemoryStream;
  14  channel: word;
  15  end;
  16 type tMessageHandler=procedure(msg:tSMsg);
  17 procedure SetMsgHandler(OpCode:byte; handler:tMessageHandler);
  18 procedure SetHiMsgHandler(handler:tMessageHandler);
  19
  20 procedure SendMessage(const data; len:word; const rcpt:tNetAddr );
  21 {procedure SendReply(const data; len:word; const rcpt:tSMsg );}
  22 procedure SendMessage(const data; len:word; const rcpt:tNetAddr; channel:word );
  23
  24 {#Sheduling and watching#}
  25 type tFDEventHandler=procedure(ev:Word) of object;
  26 type tOnTimer=procedure of object;
  27 procedure WatchFD(fd:tHandle; h:tFDEventHandler);
  28 procedure Shedule(timeout{ms}: LongWord; h:tOnTimer);
  29 procedure UnShedule(h:tOnTimer);
  30  {note unshed will fail when called from OnTimer proc}
  31
  32 type tObjMessageHandler=procedure(msg:tSMsg) of object;
  33 {deliver message from peer to the object}
  34 procedure SetMsgHandler(OpCode:byte; from:tNetAddr; handler:tObjMessageHandler);
  35
  36 type tTimeVal=UnixType.timeval;
  37 var iNow:tTimeVal;
  38
  39 IMPLEMENTATION
  40
  41 USES SysUtils,Sockets,BaseUnix
  42      ,Unix
  43      ;
  44
  45 {aim for most simple implementation, since could be extended anytime}
  46
  47 var s_inet:tSocket;
  48
  49 type tPollTop=0..7;
  50 var pollArr: packed array [tPollTop] of tPollFd;
  51 type tFdHndDsc=record
  52  cb: tFDEventHandler; {proc+object}
  53  end;
  54 var pollHnd: array [tPollTop] of tFdHndDsc;
  55 var pollTop: tPollTop;
  56
  57 var hnd: array [1..36] of tMessageHandler;
  58 var HiHnd: tMessageHandler;
  59
  60 type tSheduled_ptr=^tSheduled; tSheduled=record
  61  left:LongWord;
  62  cb:tOnTimer;
  63  next:tSheduled_ptr;
  64  end;
  65 var ShedTop: ^tSheduled;
  66 var ShedUU: ^tSheduled;
  67 var LastShed: UnixType.timeval;
  68 var PollTimeout:LongInt;
  69
  70 procedure SC(fn:pointer; retval:cint);
  71  begin
  72   if retval < 0 then begin
  73    raise eXception.Create(Format('Socket error %d operation %P',[SocketError,fn]));
  74   end;
  75  end;
  76
  77 procedure s_SetupInet;
  78  var bind_addr:tInetSockAddr;
  79  var turnon:cint;
  80  begin
  81   with bind_addr do begin
  82    family:=AF_INET;
  83    port:=htons(3511);
  84    addr:=0; {any}
  85    s_inet:=fpSocket(family,SOCK_DGRAM,IPPROTO_UDP);
  86    SC(@fpSocket,s_inet);
  87    turnon:=IP_PMTUDISC_DO;
  88    SC(@fpsetsockopt,fpsetsockopt(s_inet, IPPROTO_IP, IP_MTU_DISCOVER, @turnon, sizeof(turnon)));
  89   end;
  90   SC(@fpBind,fpBind(s_inet,@bind_addr,sizeof(bind_addr)));
  91   with PollArr[0] do begin
  92    fd:=s_inet;
  93    events:=pollIN;
  94    revents:=0;
  95   end;
  96  end;
  97
  98 var Terminated:boolean=false;
  99
 100 procedure SendMessage(const data; len:word; const rcpt:tSockAddrL );
 101  var rc:Integer;
 102  begin
 103  {SC(@fpsendto,}fpsendto(s_inet,@data,len,0,@rcpt,sizeof(sockaddr_in)){)};
 104 end;
 105 procedure SendMessage(const data; len:word; const rcpt:tNetAddr );
 106  var sa:tSockAddrL;
 107  begin
 108  rcpt.ToSocket(sa);
 109  SendMessage(data,len,sa);
 110 end;
 111 procedure SendMessage(const data; len:word; const rcpt:tNetAddr; channel:word );
 112  begin
 113  SendMessage(data,len,rcpt);
 114  {todo: optimization??}
 115 end;
 116
 117 procedure SignalHandler(sig:cint);CDecl;
 118  begin
 119   writeln;
 120   if terminated then raise eControlC.Create('CtrlC DoubleTap') ;
 121   Terminated:=true;
 122   writeln('Shutdown requested');
 123  end;
 124
 125 {index=iphash+opcode}
 126 type tPeerTableBucket=record
 127  opcode:byte;
 128  remote:tNetAddr;
 129  handler:tObjMessageHandler;
 130 end;
 131 var PT:array [0..255] of ^tPeerTableBucket;
 132 var PT_opcodes: set of 1..36;
 133
 134 function FindPT(opcode:byte; const addr:tNetAddr):Word; { $FFFF=fail}
 135  var i,o:word;
 136  begin
 137  i:=(addr.hash+opcode) mod high(PT); {0..63}
 138  for o:=0 to high(PT) do begin
 139   result:=(i+o) mod high(PT);
 140   if not assigned(PT[result]) then break;
 141   if (PT[result]^.opcode=opcode) and (PT[result]^.remote=addr) then exit;
 142  end;
 143  result:=$FFFF;
 144 end;
 145
 146 procedure UnSetMsgHandler(const from:tNetAddr; opcode:byte);
 147  var i,h:word;
 148  begin
 149  h:=FindPT(opcode,from);
 150  if h=$FFFF then exit;
 151  Dispose(PT[h]);
 152  PT[h]:=nil;
 153  {go reverse exit on null, hash them, match: move to H and stop}
 154  i:=h-1;
 155  while (i<>h)and assigned(PT[i]) do begin
 156   if (PT[i]^.remote.hash+PT[i]^.opcode)=h then begin
 157    PT[h]:=PT[i];
 158    PT[i]:=nil;
 159    break;
 160   end;
 161   if i=0 then i:=high(PT) else dec(i);
 162  end;
 163 end;
 164
 165 procedure SetMsgHandler(OpCode:byte; from:tNetAddr; handler:tObjMessageHandler);
 166  var h,o,i:word;
 167  begin
 168  UnSetMsgHandler(from,opcode);
 169  if handler=nil then exit;
 170  h:=(from.hash+opcode) mod high(PT);
 171  for o:=0 to high(PT) do begin
 172   i:=(h+o) mod high(PT);
 173   if not assigned(PT[i]) then break;
 174  end;
 175  New(PT[i]);
 176  PT[i]^.opcode:=OpCode;
 177  PT[i]^.remote:=from;
 178  PT[i]^.handler:=handler;
 179  Include(PT_opcodes,opcode);
 180 end;
 181
 182 {do not waste stack on statics}
 183  var EventsCount:integer;
 184  var Buffer:array [1..1024] of byte;
 185  var pkLen:LongWord;
 186  var From:tSockAddrL; {use larger struct so everything fits}
 187  var FromLen:LongWord;
 188  var curhnd:tMessageHandler;
 189  var curhndo:tObjMessageHandler;
 190  var Msg:tSMsg;
 191  var tp:tPollTop;
 192
 193 procedure DoSock(var p:tPollFD);
 194  var FromG:tNetAddr;
 195  var ptidx:byte;
 196  begin
 197  curhnd:=nil;
 198  curhndo:=nil;
 199  if (p.revents and pollIN)=0 then exit;
 200  FromLen:=sizeof(From);
 201  pkLen:=fprecvfrom(p.FD,@Buffer,sizeof(Buffer),0,@from,@fromlen);
 202  SC(@fprecvfrom,pkLen);
 203  p.revents:=0;
 204  FromG.FromSocket(from);
 205  Msg.Source:=@FromG; {!thread}
 206  Msg.Length:=pkLen;
 207  Msg.Data:=@Buffer; {!thread}
 208  Msg.stream.Init(@Buffer,pkLen,sizeof(Buffer));
 209  Msg.channel:=0; {!multisocket}
 210  if Buffer[1]>128 then curhnd:=HiHnd else if Buffer[1]<=high(hnd) then curhnd:=hnd[Buffer[1]];
 211  if Buffer[1] in PT_opcodes then ptidx:=FindPT(Buffer[1],FromG) else ptidx:=0;
 212  if ptidx>0 then curhndo:=PT[ptidx]^.handler;
 213 end;
 214
 215 procedure ShedRun;
 216  var cur:^tSheduled;
 217  var pcur:^pointer;
 218  var now:UnixType.timeval absolute iNow;
 219  var delta:LongWord;
 220  var olTop:^tSheduled;
 221  begin
 222  {Sheduling}
 223  olTop:=ShedTop;
 224  pcur:=@olTop;
 225  cur:=pcur^;
 226  ShedTop:=nil; {unlink the current shed list}
 227  fpgettimeofday(@Now,nil);
 228  delta:=(Now.tv_sec-LastShed.tv_sec);
 229  if delta>6 then delta:=5000 else delta:=(delta*1000)+((Now.tv_usec-LastShed.tv_usec) div 1000);
 230  LastShed:=Now;
 231  //writeln('DeltaTime: ',delta);
 232  while assigned(cur) do begin
 233   if (cur^.left<=delta)or(cur^.left=0) then begin
 234    cur^.cb;
 235    pcur^:=cur^.next;
 236    cur^.next:=ShedUU;
 237    ShedUU:=cur;
 238    cur:=pcur^;
 239   end else begin
 240    DEC(cur^.left,delta);
 241    //writeln('Left: ',cur^.left);
 242    if pollTimeOut>cur^.left then PollTimeOut:=cur^.left;
 243    pcur:=@cur^.next;
 244    cur:=cur^.next;
 245   end;
 246  end;
 247  pcur^:=ShedTop; {append newly added tasks to end of untriggererd list}
 248  ShedTop:=olTop; {link in the untriggered tasks}
 249  cur:=olTop;
 250  while assigned(cur) do begin
 251   if cur^.left<PollTimeout then PollTimeout:=cur^.left;
 252   cur:=cur^.next;
 253  end;
 254  if pollTimeout=0 then pollTimeOut:=1;
 255 end;
 256
 257 procedure Main;
 258  begin
 259  s_setupInet;
 260  while not terminated  do begin
 261   PollTimeout:=5000;
 262   ShedRun;
 263   EventsCount:=fpPoll(@PollArr[0],PollTop,PollTimeout);
 264   if (eventscount=-1)and terminated then break;
 265   if eventscount=-1 then break;  {fixme: print error}
 266   if eventscount=0 then continue else begin
 267    {INET socket}
 268    DoSock(PollArr[0]);
 269    if assigned(curhndo) then curhndo(msg)
 270    else if assigned(curhnd) then curhnd(msg)
 271    else raise eXception.Create('No handler for opcode '+IntToStr(Buffer[1]));
 272    {INET6...}
 273    {Generic}
 274    for tp:=1 to pollTop do if PollArr[tp].revents>0 then begin
 275     PollHnd[tp].CB(PollArr[tp].rEvents);
 276     PollArr[tp].revents:=0;
 277    end;
 278   end;
 279  end;
 280  write('Loop broken [');
 281  CloseSocket(s_inet);
 282  writeln(']');
 283 end;
 284
 285 procedure SetMsgHandler(OpCode:byte; handler:tMessageHandler);
 286 begin assert(hnd[OpCode]=nil); hnd[OpCode]:=handler; end;
 287 procedure SetHiMsgHandler(handler:tMessageHandler);
 288 begin Hihnd:=handler; end;
 289
 290 procedure WatchFD(fd:tHandle; h:tFDEventHandler);
 291  var opt: tPollTop;
 292 begin
 293  if assigned(h) then begin
 294   PollHnd[pollTop].CB:=h;
 295   PollArr[pollTop].fd:=fd;
 296   PollArr[pollTop].events:=POLLERR or POLLHUP or POLLIN or POLLPRI or
 297   POLLRDBAND or POLLRDNORM;
 298   PollArr[pollTop].revents:=0;
 299   //writeln('Add watch ',pollTop,' on ',fd,' to ',IntToHex(qword(@h),8));
 300   Inc(PollTop);
 301  end else for opt:=0 to high(opt) do if PollArr[opt].fd=fd then begin
 302   if (pollTop-1)>opt then begin
 303    PollArr[opt]:=PollArr[pollTop-1];
 304    PollHnd[opt]:=PollHnd[pollTop-1];
 305   end;
 306   dec(pollTop);
 307   PollArr[pollTop].fd:=-1;
 308   PollArr[pollTop].events:=0;
 309   PollArr[pollTop].revents:=0;
 310   break;
 311  end;
 312 end;
 313
 314 procedure Shedule(timeout{ms}: LongWord; h:tOnTimer);
 315  var old:^tSheduled;
 316  begin
 317  old:=ShedTop;
 318  if Assigned(ShedUU) then begin
 319   ShedTop:=ShedUU;
 320   ShedUU:=ShedUU^.next;
 321  end else New(ShedTop);
 322  ShedTop^.Left:=timeout;
 323  ShedTop^.CB:=h;
 324  ShedTop^.Next:=old;
 325 end;
 326
 327 procedure UnShedule(h:tOnTimer);
 328  var cur:^tSheduled;
 329  var pcur:^pointer;
 330  begin
 331  pcur:=@ShedTop;
 332  cur:=pcur^;
 333  while assigned(cur) do begin
 334   if cur^.cb=h then begin
 335    pcur^:=cur^.next; {unlink from main list}
 336    cur^.next:=ShedUU; ShedUU:=cur; {link to unused}
 337    break;
 338   end else begin
 339    pcur:=@cur^.next;
 340    cur:=pcur^;
 341   end;
 342  end;
 343 end;
 344
 345 var i:byte;
 346 BEGIN
 347  Randomize;
 348  fpSignal(SigInt,@SignalHandler);
 349  fpSignal(SigTerm,@SignalHandler);
 350  for i:=1 to high(hnd) do hnd[i]:=nil;
 351  for i:=1 to high(PT) do PT[i]:=nil;
 352  PT_opcodes:=[];
 353  pollTop:=1; {1 for basic listen}
 354  ShedTop:=nil;
 355  ShedUU:=nil; {todo: allocate a few to improve paging}
 356  fpgettimeofday(@LastShed,nil);
 357 END.