ServerLoop.pas

   1 UNIT ServerLoop;
   2
   3 INTERFACE
   4 uses MemStream,NetAddr;
   5
   6 procedure Main;
   7
   8 type tSMsg=object
   9  Source: ^tNetAddr;
  10  Length: {Long}Word;
  11  Data: pointer;
  12  stream: tMemoryStream;
  13  channel: word;
  14  end;
  15
  16 type tMessageHandler=procedure(msg:tSMsg);
  17
  18 procedure SetMsgHandler(OpCode:byte; handler:tMessageHandler);
  19 procedure SetHiMsgHandler(handler:tMessageHandler);
  20
  21 type tFDEventHandler=procedure(ev:Word) of object;
  22 type tOnTimer=procedure of object;
  23
  24 procedure WatchFD(fd:tHandle; h:tFDEventHandler);
  25 procedure Shedule(timeout{ms}: LongWord; h:tOnTimer);
  26 procedure UnShedule(h:tOnTimer);
  27
  28 IMPLEMENTATION
  29
  30 USES SysUtils,Sockets,UnixType,BaseUnix
  31      ,Unix
  32      ;
  33
  34 {aim for most simple implementation, since could be extended anytime}
  35
  36 var s_inet:tSocket;
  37
  38 type tPollTop=0..7;
  39 var pollArr: packed array [tPollTop] of tPollFd;
  40 type tFdHndDsc=record
  41  cb: tFDEventHandler; {proc+object}
  42  end;
  43 var pollHnd: array [tPollTop] of tFdHndDsc;
  44 var pollTop: tPollTop;
  45
  46 var hnd: array [1..36] of tMessageHandler;
  47 var HiHnd: tMessageHandler;
  48
  49 type tSheduled_ptr=^tSheduled; tSheduled=record
  50  left:LongWord;
  51  cb:tOnTimer;
  52  next:tSheduled_ptr;
  53  end;
  54 var ShedTop: ^tSheduled;
  55 var ShedUU: ^tSheduled;
  56 var LastShed: UnixType.timeval;
  57 var PollTimeout:LongInt;
  58
  59 procedure IdleStuff;
  60 begin write('.'); end;
  61
  62 procedure SC(fn:pointer; retval:cint);
  63  begin
  64   if retval < 0 then begin
  65    raise eXception.Create(Format('Socket error %d operation %P',[SocketError,fn]));
  66   end;
  67  end;
  68
  69 procedure s_SetupInet;
  70  var bind_addr:tInetSockAddr;
  71  begin
  72   with bind_addr do begin
  73    family:=AF_INET;
  74    port:=htons(3511);
  75    addr:=0; {any}
  76    s_inet:=fpSocket(family,SOCK_DGRAM,IPPROTO_UDP);
  77    SC(@fpSocket,s_inet);
  78   end;
  79   SC(@fpBind,fpBind(s_inet,@bind_addr,sizeof(bind_addr)));
  80   with PollArr[0] do begin
  81    fd:=s_inet;
  82    events:=pollIN;
  83    revents:=0;
  84   end;
  85  end;
  86
  87 var Terminated:boolean=false;
  88
  89 procedure SendMessage(const data; len:word; const rcpt:tSockAddr );
  90  var rc:Integer;
  91  begin
  92  SC(@fpsendto,fpsendto(s_inet,@data,len,0,@rcpt,sizeof(sockaddr_in)));
  93 end;
  94
  95 procedure SignalHandler(sig:cint);CDecl;
  96  begin
  97   writeln;
  98   if terminated then raise eControlC.Create('CtrlC DoubleTap') ;
  99   Terminated:=true;
 100   writeln('Shutdown requested');
 101  end;
 102
 103 {do not waste stack on statics}
 104  var EventsCount:integer;
 105  var Buffer:array [1..1024] of byte;
 106  var pkLen:LongWord;
 107  var From:tSockAddrL; {use larger struct so everything fits}
 108  var FromLen:LongWord;
 109  var FromG:tNetAddr;
 110  var curhnd:tMessageHandler;
 111  var Msg:tSMsg;
 112  var tp:tPollTop;
 113
 114 procedure PrepareHandler;
 115  begin
 116  FromG.FromSocket(from);
 117  if Buffer[1]>128 then curhnd:=HiHnd else curhnd:=hnd[Buffer[1]];
 118  if not assigned(curhnd) then raise eXception.Create('No handler for opcode '+IntToStr(Buffer[1]));
 119  Msg.Source:=@FromG; {!thread}
 120  Msg.Length:=pkLen;
 121  Msg.Data:=@Buffer; {!thread}
 122  Msg.stream.Init(@Buffer,pkLen,sizeof(Buffer));
 123  Msg.channel:=0; {!multisocket}
 124 end;
 125
 126 procedure ShedRun;
 127  var cur:^tSheduled;
 128  var pcur:^pointer;
 129  var now:UnixType.timeval;
 130  var delta:LongWord;
 131  var olTop:^tSheduled;
 132  begin
 133  {Sheduling}
 134  olTop:=ShedTop;
 135  pcur:=@olTop;
 136  cur:=pcur^;
 137  ShedTop:=nil; {unlink the current shed list}
 138  fpgettimeofday(@Now,nil);
 139  delta:=(Now.tv_sec-LastShed.tv_sec);
 140  if delta>6 then delta:=5000 else delta:=(delta*1000)+((Now.tv_usec-LastShed.tv_usec) div 1000);
 141  LastShed:=Now;
 142  writeln('DeltaTime: ',delta);
 143  while assigned(cur) do begin
 144   if cur^.left<delta then begin
 145    cur^.cb;
 146    pcur^:=cur^.next;
 147    cur^.next:=ShedUU;
 148    ShedUU:=cur;
 149    cur:=pcur^;
 150   end else begin
 151    DEC(cur^.left,delta);
 152    if pollTimeOut>cur^.left then PollTimeOut:=cur^.left;
 153    //if pollTimeout>20 then pollTimeOut:=pollTimeOut div 2;
 154    if pollTimeout=0 then pollTimeOut:=1;
 155    pcur:=@cur^.next;
 156    cur:=cur^.next;
 157   end;
 158  end;
 159  pcur^:=ShedTop; {append newly added tasks to end of untriggererd list}
 160  ShedTop:=olTop; {link in the untriggered tasks}
 161 end;
 162
 163 procedure Main;
 164  begin
 165  s_setupInet;
 166  while not terminated  do begin
 167   PollTimeout:=5000;
 168   ShedRun;
 169   EventsCount:=fpPoll(@PollArr[0],PollTop,PollTimeout);
 170   if (eventscount=-1)and terminated then break;
 171   if eventscount=-1 then break;  {fixme: print error}
 172   if eventscount=0 then IdleStuff else begin
 173    {INET socket}
 174    with PollArr[0] do begin
 175     if (revents and pollIN)>0 then begin
 176      FromLen:=sizeof(From);
 177      pkLen:=fprecvfrom(s_inet,@Buffer,sizeof(Buffer),0,@from,@fromlen);
 178      SC(@fprecvfrom,pkLen);
 179      PrepareHandler;
 180      curhnd(Msg);
 181      revents:=0;
 182     end;
 183    end;
 184    {INET6...}
 185    {Generic}
 186    for tp:=1 to pollTop do if PollArr[tp].revents>0 then begin
 187     PollHnd[tp].CB(PollArr[tp].rEvents);
 188     PollArr[tp].revents:=0;
 189    end;
 190   end;
 191  end;
 192  write('Loop broken [');
 193  CloseSocket(s_inet);
 194  writeln(']');
 195 end;
 196
 197 procedure SetMsgHandler(OpCode:byte; handler:tMessageHandler);
 198 begin hnd[OpCode]:=handler; end;
 199 procedure SetHiMsgHandler(handler:tMessageHandler);
 200 begin Hihnd:=handler; end;
 201
 202 procedure WatchFD(fd:tHandle; h:tFDEventHandler);
 203  var opt: tPollTop;
 204 begin
 205  if assigned(h) then begin
 206   PollHnd[pollTop].CB:=h;
 207   PollArr[pollTop].fd:=fd;
 208   PollArr[pollTop].events:=POLLERR or POLLHUP or POLLIN or POLLPRI or
 209   POLLRDBAND or POLLRDNORM;
 210   PollArr[pollTop].revents:=0;
 211   //writeln('Add watch ',pollTop,' on ',fd,' to ',IntToHex(qword(@h),8));
 212   Inc(PollTop);
 213  end else for opt:=0 to high(opt) do if PollArr[opt].fd=fd then begin
 214   if (pollTop-1)>opt then begin
 215    PollArr[opt]:=PollArr[pollTop-1];
 216    PollHnd[opt]:=PollHnd[pollTop-1];
 217   end;
 218   dec(pollTop);
 219   PollArr[pollTop].fd:=-1;
 220   PollArr[pollTop].events:=0;
 221   PollArr[pollTop].revents:=0;
 222   break;
 223  end;
 224 end;
 225
 226 procedure Shedule(timeout{ms}: LongWord; h:tOnTimer);
 227  var old:^tSheduled;
 228  begin
 229  old:=ShedTop;
 230  if Assigned(ShedUU) then begin
 231   ShedTop:=ShedUU;
 232   ShedUU:=ShedUU^.next;
 233  end else New(ShedTop);
 234  ShedTop^.Left:=timeout;
 235  ShedTop^.CB:=h;
 236  ShedTop^.Next:=old;
 237 end;
 238
 239 procedure UnShedule(h:tOnTimer);
 240  var cur:^tSheduled;
 241  var pcur:^pointer;
 242  begin
 243  pcur:=@ShedTop;
 244  cur:=pcur^;
 245  while assigned(cur) do begin
 246   if cur^.cb=h then begin
 247    pcur^:=cur^.next; {unlink from main list}
 248    cur^.next:=ShedUU; ShedUU:=cur; {link to unused}
 249    break;
 250   end else begin
 251    pcur:=@cur^.next;
 252    cur:=pcur^;
 253   end;
 254  end;
 255 end;
 256
 257 var i:byte;
 258 BEGIN
 259  fpSignal(SigInt,@SignalHandler);
 260  fpSignal(SigTerm,@SignalHandler);
 261  for i:=1 to high(hnd) do hnd[i]:=nil;
 262  pollTop:=1; {1 for basic listen}
 263  ShedTop:=nil;
 264  ShedUU:=nil;
 265  fpgettimeofday(@LastShed,nil);
 266 END.