sendrecv.cpp

   1 /*
   2  *  datasendrecv.cpp
   3  *  serp++
   4  *
   5  *  Created by Victor Grishchenko on 3/6/09.
   6  *  Copyright 2009 Delft University of Technology. All rights reserved.
   7  *
   8  */
   9 #include "p2tp.h"
  10 #include "compat/util.h"
  11
  12
  13 using namespace p2tp;
  14 using namespace std;
  15
  16 /*
  17  TODO  25 Oct 18:55
  18  - range: ALL
  19  - randomized testing of advanced ops (new testcase)
  20  */
  21
  22 void    Channel::AddPeakHashes (Datagram& dgram) {
  23     for(int i=0; i<file().peak_count(); i++) {
  24         bin64_t peak = file().peak(i);
  25         dgram.Push8(P2TP_HASH);
  26         dgram.Push32((uint32_t)peak);
  27         dgram.PushHash(file().peak_hash(i));
  28         //DLOG(INFO)<<"#"<<id<<" +pHASH"<<file().peak(i);
  29         dprintf("%s #%u +phash %s\n",tintstr(),id,peak.str());
  30     }
  31 }
  32
  33
  34 void    Channel::AddUncleHashes (Datagram& dgram, bin64_t pos) {
  35     bin64_t peak = file().peak_for(pos);
  36     while (pos!=peak && /*((NOW&3)==3 || !data_out_cap_.within(pos.parent())) &&*/
  37             ack_in_.get(pos.parent())==bins::EMPTY) {
  38         bin64_t uncle = pos.sibling();
  39         dgram.Push8(P2TP_HASH);
  40         dgram.Push32((uint32_t)uncle);
  41         dgram.PushHash( file().hash(uncle) );
  42         //DLOG(INFO)<<"#"<<id<<" +uHASH"<<uncle;
  43         dprintf("%s #%u +hash %s\n",tintstr(),id,uncle.str());
  44         pos = pos.parent();
  45     }
  46 }
  47
  48
  49 bin64_t        Channel::DequeueHint () {
  50     if (hint_in_.empty() && last_recv_time_>NOW-rtt_avg_-TINT_SEC) {
  51         uint64_t twist = peer_channel_id_;  // got no hints, send something randomly
  52         twist &= file().peak(0); // may make it semi-seq here
  53         file().ack_out().twist(twist);
  54         ack_in_.twist(twist);
  55         bin64_t my_pick =
  56             file().ack_out().find_filtered(ack_in_,bin64_t::ALL,bins::FILLED);
  57         while (my_pick.width()>max(1,(int)cwnd_))
  58             my_pick = my_pick.left();
  59         file().ack_out().twist(0);
  60         ack_in_.twist(0);
  61         if (my_pick!=bin64_t::NONE) {
  62             my_pick = my_pick.twisted(twist);
  63             hint_in_.push_back(my_pick);
  64             dprintf("%s #%u *hint %s\n",tintstr(),id,my_pick.str());
  65         }
  66     }
  67     bin64_t send = bin64_t::NONE;
  68     while (!hint_in_.empty() && send==bin64_t::NONE) {
  69         bin64_t hint = hint_in_.front().bin;
  70         tint time = hint_in_.front().time;
  71         hint_in_.pop_front();
  72         while (!hint.is_base()) { // FIXME optimize; possible attack
  73             hint_in_.push_front(tintbin(time,hint.right()));
  74             hint = hint.left();
  75         }
  76         //if (time < NOW-TINT_SEC*3/2 )
  77         //    continue;  bad idea
  78         if (ack_in_.get(hint)!=bins::FILLED)
  79             send = hint;
  80     }
  81     uint64_t mass = 0;
  82     for(int i=0; i<hint_in_.size(); i++)
  83         mass += hint_in_[i].bin.width();
  84     dprintf("%s #%u dequeued %s [%lli]\n",tintstr(),id,send.str(),mass);
  85     return send;
  86 }
  87
  88
  89 void    Channel::AddHandshake (Datagram& dgram) {
  90     if (!peer_channel_id_) { // initiating
  91         dgram.Push8(P2TP_HASH);
  92         dgram.Push32(bin64_t::ALL32);
  93         dgram.PushHash(file().root_hash());
  94         dprintf("%s #%u +hash ALL %s\n",
  95                 tintstr(),id,file().root_hash().hex().c_str());
  96     }
  97     dgram.Push8(P2TP_HANDSHAKE);
  98     int encoded = EncodeID(id);
  99     dgram.Push32(encoded);
 100     dprintf("%s #%u +hs %x\n",tintstr(),id,encoded);
 101     ack_out_.clear();
 102     AddAck(dgram);
 103 }
 104
 105
 106 void    Channel::Send () {
 107     Datagram dgram(socket_,peer());
 108     dgram.Push32(peer_channel_id_);
 109     bin64_t data = bin64_t::NONE;
 110     if ( is_established() ) {
 111         // FIXME: seeder check
 112         AddAck(dgram);
 113         if (!file().is_complete())
 114             AddHint(dgram);
 115         AddPex(dgram);
 116         CleanDataOut();
 117         data = AddData(dgram);
 118     } else {
 119         AddHandshake(dgram);
 120         AddAck(dgram);
 121     }
 122     dprintf("%s #%u sent %ib %s:%x\n",
 123             tintstr(),id,dgram.size(),peer().str(),peer_channel_id_);
 124     if (dgram.size()==4) {// only the channel id; bare keep-alive
 125         data = bin64_t::ALL;
 126         if (data_out_.size()<cwnd_ && send_control_!=KEEP_ALIVE_CONTROL) {
 127             if ( cwnd_ < 1 )
 128                 SwitchSendControl(KEEP_ALIVE_CONTROL);
 129             else
 130                 cwnd_ /= 2;
 131         }
 132         //if (data_out_.empty() && send_control_!=KEEP_ALIVE_CONTROL)
 133         //     SwitchSendControl(KEEP_ALIVE_CONTROL);// we did our best
 134         //if (NOW<last_send_time_+MAX_SEND_INTERVAL) // no need for keepalive
 135         //    return; // don't send empty dgram
 136     }
 137     if (dgram.Send()==-1)
 138         print_error("can't send datagram");
 139     last_send_time_ = NOW;
 140     sent_since_recv_++;
 141     dgrams_sent_++;
 142 }
 143
 144
 145 void    Channel::AddHint (Datagram& dgram) {
 146
 147     tint plan_for = max(TINT_SEC,rtt_avg_*4);
 148
 149     tint timed_out = NOW - plan_for*2;
 150     while ( !hint_out_.empty() && hint_out_.front().time < timed_out ) {
 151         hint_out_size_ -= hint_out_.front().bin.width();
 152         hint_out_.pop_front();
 153     }
 154
 155     /*int peer_cwnd = (int)(rtt_avg_ / dip_avg_);
 156     if (!peer_cwnd)
 157         peer_cwnd = 1;*/
 158     int plan_pck = std::max ( 1LL, plan_for / dip_avg_ );
 159
 160     if ( hint_out_size_ < plan_pck ) {
 161
 162         int diff = plan_pck - hint_out_size_; // TODO: aggregate
 163         bin64_t hint = transfer().picker().Pick(ack_in_,diff,NOW+plan_for*2);
 164
 165         if (hint!=bin64_t::NONE) {
 166             dgram.Push8(P2TP_HINT);
 167             dgram.Push32(hint);
 168             dprintf("%s #%u +hint %s [%lli]\n",tintstr(),id,hint.str(),hint_out_size_);
 169             hint_out_.push_back(hint);
 170             hint_out_size_ += hint.width();
 171         } else
 172             dprintf("%s #%u Xhint\n",tintstr(),id);
 173
 174     }
 175 }
 176
 177
 178 bin64_t        Channel::AddData (Datagram& dgram) {
 179
 180     if (!file().size()) // know nothing
 181         return bin64_t::NONE;
 182
 183     bin64_t tosend = bin64_t::NONE;
 184     if (data_out_.size()<cwnd_ && last_data_out_time_<=NOW-send_interval_) {
 185         tosend = DequeueHint();
 186         if (tosend==bin64_t::NONE)
 187             dprintf("%s #%u out of hints #sendctrl\n",tintstr(),id);
 188     } else
 189         dprintf("%s #%u no cwnd #sendctrl\n",tintstr(),id);
 190
 191     if (tosend==bin64_t::NONE)// && (last_data_out_time_>NOW-TINT_SEC || data_out_.empty()))
 192         return bin64_t::NONE; // once in a while, empty data is sent just to check rtt FIXED
 193
 194     if (ack_in_.is_empty() && file().size())
 195         AddPeakHashes(dgram);
 196     AddUncleHashes(dgram,tosend);
 197     if (!ack_in_.is_empty()) // TODO: cwnd_>1
 198         data_out_cap_ = tosend;
 199
 200     if (dgram.size()>254) {
 201         dgram.Send(); // kind of fragmentation
 202         dgram.Push32(peer_channel_id_);
 203     }
 204
 205     dgram.Push8(P2TP_DATA);
 206     dgram.Push32(tosend.to32());
 207
 208     uint8_t buf[1024];
 209     size_t r = pread(file().file_descriptor(),buf,1024,tosend.base_offset()<<10);
 210     // TODO: corrupted data, retries, caching
 211     if (r<0) {
 212         print_error("error on reading");
 213         return bin64_t::NONE;
 214     }
 215     assert(dgram.space()>=r+4+1);
 216     dgram.Push(buf,r);
 217
 218     last_data_out_time_ = NOW;
 219     data_out_.push_back(tosend);
 220     dprintf("%s #%u +data %s\n",tintstr(),id,tosend.str());
 221
 222     return tosend;
 223 }
 224
 225
 226 void    Channel::AddTs (Datagram& dgram) {
 227     dgram.Push8(P2TP_TS);
 228     dgram.Push64(data_in_.time);
 229     dprintf("%s #%u +ts %s\n",tintstr(),id,tintstr(data_in_.time));
 230 }
 231
 232
 233 void    Channel::AddAck (Datagram& dgram) {
 234     if (data_in_dbl_!=bin64_t::NONE) { // TODO: do redundancy better
 235         dgram.Push8(P2TP_ACK);
 236         dgram.Push32(data_in_dbl_.to32());
 237         data_in_dbl_=bin64_t::NONE;
 238     }
 239     if (data_in_.time!=TINT_NEVER) { // TODO: ACK NONE for corrupted data
 240         AddTs(dgram);
 241         bin64_t pos = file().ack_out().cover(data_in_.bin);
 242         dgram.Push8(P2TP_ACK);
 243         dgram.Push32(pos.to32());
 244         //dgram.Push64(data_in_.time);
 245         ack_out_.set(pos);
 246         dprintf("%s #%u +ack %s %s\n",tintstr(),id,pos.str(),tintstr(data_in_.time));
 247         data_in_ = tintbin(TINT_NEVER,bin64_t::NONE);
 248         if (pos.layer()>2)
 249             data_in_dbl_ = pos;
 250     }
 251     for(int count=0; count<4; count++) {
 252         bin64_t ack = file().ack_out().find_filtered(ack_out_, bin64_t::ALL, bins::FILLED);
 253         if (ack==bin64_t::NONE)
 254             break;
 255         ack = file().ack_out().cover(ack);
 256         ack_out_.set(ack);
 257         dgram.Push8(P2TP_ACK);
 258         dgram.Push32(ack.to32());
 259         dprintf("%s #%u +ack %s\n",tintstr(),id,ack.str());
 260     }
 261 }
 262
 263
 264 void    Channel::Recv (Datagram& dgram) {
 265     dprintf("%s #%u recvd %i\n",tintstr(),id,dgram.size()+4);
 266     peer_send_time_ = 0; // has scope of 1 datagram
 267     dgrams_rcvd_++;
 268     if (last_send_time_ && rtt_avg_==TINT_SEC && dev_avg_==0) {
 269         rtt_avg_ = NOW - last_send_time_;
 270         dev_avg_ = rtt_avg_;
 271         dip_avg_ = rtt_avg_;
 272         dprintf("%s #%u rtt init %lli\n",tintstr(),id,rtt_avg_);
 273     }
 274     bin64_t data = dgram.size() ? bin64_t::NONE : bin64_t::ALL;
 275     while (dgram.size()) {
 276         uint8_t type = dgram.Pull8();
 277         switch (type) {
 278             case P2TP_HANDSHAKE: OnHandshake(dgram); break;
 279             case P2TP_DATA:      data=OnData(dgram); break;
 280             case P2TP_TS:        OnTs(dgram); break;
 281             case P2TP_ACK:       OnAck(dgram); break;
 282             case P2TP_HASH:      OnHash(dgram); break;
 283             case P2TP_HINT:      OnHint(dgram); break;
 284             case P2TP_PEX_ADD:   OnPex(dgram); break;
 285             default:
 286                 eprintf("%s #%u ?msg id unknown %i\n",tintstr(),id,(int)type);
 287                 return;
 288         }
 289     }
 290     last_recv_time_ = NOW;
 291     sent_since_recv_ = 0;
 292 }
 293
 294
 295 void    Channel::OnHash (Datagram& dgram) {
 296     bin64_t pos = dgram.Pull32();
 297     Sha1Hash hash = dgram.PullHash();
 298     file().OfferHash(pos,hash);
 299     //DLOG(INFO)<<"#"<<id<<" .HASH"<<(int)pos;
 300     dprintf("%s #%u -hash %s\n",tintstr(),id,pos.str());
 301 }
 302
 303
 304 void    Channel::CleanHintOut (bin64_t pos) {
 305     int hi = 0;
 306     while (hi<hint_out_.size() && !pos.within(hint_out_[hi].bin))
 307         hi++;
 308     if (hi==hint_out_.size())
 309         return; // something not hinted or hinted in far past
 310     while (hi--) { // removing likely snubbed hints
 311         hint_out_size_ -= hint_out_.front().bin.width();
 312         hint_out_.pop_front();
 313     }
 314     while (hint_out_.front().bin!=pos) {
 315         tintbin f = hint_out_.front();
 316         f.bin = f.bin.towards(pos);
 317         hint_out_.front().bin = f.bin.sibling();
 318         hint_out_.push_front(f);
 319     }
 320     hint_out_.pop_front();
 321     hint_out_size_--;
 322 }
 323
 324
 325 bin64_t Channel::OnData (Datagram& dgram) {
 326     bin64_t pos = dgram.Pull32();
 327     uint8_t *data;
 328     int length = dgram.Pull(&data,1024);
 329     bool ok = (pos==bin64_t::NONE) || file().OfferData(pos, (char*)data, length) ;
 330     dprintf("%s #%u %cdata %s\n",tintstr(),id,ok?'-':'!',pos.str());
 331     data_in_ = tintbin(NOW,bin64_t::NONE);
 332     if (!ok)
 333         return bin64_t::NONE;
 334     data_in_.bin = pos;
 335     if (pos!=bin64_t::NONE) {
 336         if (last_data_in_time_) {
 337             tint dip = NOW - last_data_in_time_;
 338             dip_avg_ = ( dip_avg_*3 + dip ) >> 2;
 339         }
 340         last_data_in_time_ = NOW;
 341     }
 342     CleanHintOut(pos);
 343     return pos;
 344 }
 345
 346
 347 void    Channel::CleanDataOut (bin64_t ackd_pos) { // TODO: isn't it too long?
 348
 349     int max_ack_off = 0;
 350     //FIXME do LEDBAT magic somewhere here
 351
 352     if (ackd_pos!=bin64_t::NONE) {
 353         for (int i=0; i<8 && i<data_out_.size(); i++) {
 354             if (data_out_[i]!=tintbin() && data_out_[i].bin.within(ackd_pos)) {
 355                 tint rtt = NOW-data_out_[i].time;
 356                 rtt_avg_ = (rtt_avg_*7 + rtt) >> 3;
 357                 dev_avg_ = ( dev_avg_*3 + abs(rtt-rtt_avg_) ) >> 2;
 358                 dprintf("%s #%u rtt %lli dev %lli\n",tintstr(),id,rtt_avg_,dev_avg_);
 359                 bin64_t pos = data_out_[i].bin;
 360                 ack_rcvd_recent_++;
 361                 data_out_[i]=tintbin();
 362                 max_ack_off = i;
 363                 if (ackd_pos==pos)
 364                     break;
 365             }
 366         }
 367         while (!data_out_.empty() && data_out_.front().bin==bin64_t::NONE) {
 368             data_out_.pop_front();
 369             max_ack_off--;
 370         }
 371         static const int MAX_REORDERING = 2;  // the triple-ACK principle
 372         if (max_ack_off>MAX_REORDERING) {
 373             while (max_ack_off && (data_out_.front().bin==bin64_t::NONE
 374                                    || ack_in_.is_filled(data_out_.front().bin)) ) {
 375                 data_out_.pop_front();
 376                 max_ack_off--;
 377             }
 378             while (max_ack_off>MAX_REORDERING) {
 379                 ack_not_rcvd_recent_++;
 380                 dprintf("%s #%u Rdata %s\n",tintstr(),id,data_out_.front().bin.str());
 381                 data_out_.pop_front();
 382                 max_ack_off--;
 383                 data_out_cap_ = bin64_t::ALL;
 384             }
 385         }
 386     }
 387     tint timeout = NOW - rtt_avg_ - 4*std::max(dev_avg_,TINT_MSEC*50);
 388     while (!data_out_.empty() && data_out_.front().time<timeout) {
 389         if (data_out_.front().bin!=bin64_t::NONE && ack_in_.is_empty(data_out_.front().bin)) {
 390             ack_not_rcvd_recent_++;
 391             data_out_cap_ = bin64_t::ALL;
 392             dprintf("%s #%u Tdata %s\n",tintstr(),id,data_out_.front().bin.str());
 393         }
 394         data_out_.pop_front();
 395     }
 396     while (!data_out_.empty() && data_out_.front().bin==bin64_t::NONE)
 397         data_out_.pop_front();
 398
 399 }
 400
 401
 402 void    Channel::OnAck (Datagram& dgram) {
 403     bin64_t ackd_pos = dgram.Pull32();
 404     if (ackd_pos==bin64_t::NONE)
 405         return; // likely, brocken packet / insufficient hashes
 406     if (file().size() && ackd_pos.base_offset()>=file().packet_size()) {
 407         eprintf("invalid ack: %s\n",ackd_pos.str());
 408         return;
 409     }
 410     dprintf("%s #%u -ack %s\n",tintstr(),id,ackd_pos.str());
 411     ack_in_.set(ackd_pos);
 412     CleanDataOut(ackd_pos); // FIXME do AFTER all ACKs
 413 }
 414
 415
 416 void Channel::OnTs (Datagram& dgram) {
 417     peer_send_time_ = dgram.Pull64();
 418     dprintf("%s #%u -ts %lli\n",tintstr(),id,peer_send_time_);
 419 }
 420
 421
 422 void    Channel::OnHint (Datagram& dgram) {
 423     bin64_t hint = dgram.Pull32();
 424     hint_in_.push_back(hint);
 425     //ack_in_.set(hint,bins::EMPTY);
 426     //RequeueSend(cc_->OnHintRecvd(hint));
 427     dprintf("%s #%u -hint %s\n",tintstr(),id,hint.str());
 428 }
 429
 430
 431 void Channel::OnHandshake (Datagram& dgram) {
 432     peer_channel_id_ = dgram.Pull32();
 433     dprintf("%s #%u -hs %x\n",tintstr(),id,peer_channel_id_);
 434     // self-connection check
 435     if (!SELF_CONN_OK) {
 436         uint32_t try_id = DecodeID(peer_channel_id_);
 437         if (channel(try_id) && !channel(try_id)->peer_channel_id_) {
 438             delete this;
 439             return;
 440         }
 441     }
 442     // FUTURE: channel forking
 443 }
 444
 445
 446 void Channel::OnPex (Datagram& dgram) {
 447     uint32_t ipv4 = dgram.Pull32();
 448     uint16_t port = dgram.Pull16();
 449     Address addr(ipv4,port);
 450     dprintf("%s #%u -pex %s\n",tintstr(),id,addr.str());
 451     transfer().OnPexIn(addr);
 452 }
 453
 454
 455 void    Channel::AddPex (Datagram& dgram) {
 456     int chid = transfer().RevealChannel(pex_out_);
 457     if (chid==-1 || chid==id)
 458         return;
 459     Address a = channels[chid]->peer();
 460     dgram.Push8(P2TP_PEX_ADD);
 461     dgram.Push32(a.ipv4());
 462     dgram.Push16(a.port());
 463     dprintf("%s #%u +pex %s\n",tintstr(),id,a.str());
 464 }
 465
 466
 467 Channel*    Channel::RecvDatagram (int socket) {
 468     Datagram data(socket);
 469     data.Recv();
 470     Address& addr = data.addr;
 471 #define return_log(...) { eprintf(__VA_ARGS__); return NULL; }
 472     if (data.size()<4)
 473         return_log("datagram shorter than 4 bytes %s\n",addr.str());
 474     uint32_t mych = data.Pull32();
 475     Sha1Hash hash;
 476     Channel* channel = NULL;
 477     if (!mych) { // handshake initiated
 478         if (data.size()<1+4+1+4+Sha1Hash::SIZE)
 479             return_log ("incorrect size %i initial handshake packet %s\n",data.size(),addr.str());
 480         uint8_t hashid = data.Pull8();
 481         if (hashid!=P2TP_HASH)
 482             return_log ("no hash in the initial handshake %s\n",addr.str());
 483         bin64_t pos = data.Pull32();
 484         if (pos!=bin64_t::ALL)
 485             return_log ("that is not the root hash %s\n",addr.str());
 486         hash = data.PullHash();
 487         FileTransfer* file = FileTransfer::Find(hash);
 488         if (!file)
 489             return_log ("hash %s unknown, no such file %s\n",hash.hex().c_str(),addr.str());
 490         dprintf("%s #0 -hash ALL %s\n",tintstr(),hash.hex().c_str());
 491         for(binqueue::iterator i=file->hs_in_.begin(); i!=file->hs_in_.end(); i++)
 492             if (channels[*i] && channels[*i]->peer_==data.addr &&
 493                 channels[*i]->last_recv_time_>NOW-TINT_SEC*2)
 494                 return_log("have a channel already to %s\n",addr.str());
 495         channel = new Channel(file, socket, data.address());
 496     } else {
 497         mych = DecodeID(mych);
 498         if (mych>=channels.size())
 499             return_log("invalid channel #%u, %s\n",mych,addr.str());
 500         channel = channels[mych];
 501         if (!channel)
 502             return_log ("channel #%u is already closed\n",mych,addr.str());
 503         if (channel->peer() != addr)
 504             return_log ("invalid peer address #%u %s!=%s\n",mych,channel->peer().str(),addr.str());
 505         channel->own_id_mentioned_ = true;
 506     }
 507     //dprintf("recvd %i bytes for %i\n",data.size(),channel->id);
 508     channel->Recv(data);
 509     return channel;
 510 }
 511
 512
 513 void    Channel::Loop (tint howlong) {
 514
 515     tint limit = Datagram::Time() + howlong;
 516
 517     do {
 518
 519         tint send_time(TINT_NEVER);
 520         Channel* sender(NULL);
 521         while (!sender && !send_queue.is_empty()) { // dequeue
 522             tintbin next = send_queue.pop();
 523             send_time = next.time;
 524             sender = channel((int)next.bin);
 525             if (sender && sender->next_send_time_!=send_time &&
 526                      sender->next_send_time_!=TINT_NEVER )
 527                 sender = NULL; // it was a stale entry
 528         }
 529
 530         if ( sender!=NULL && send_time<=NOW ) { // it's time
 531
 532             if (sender->next_send_time_<NOW+TINT_MIN) {  // either send
 533                 dprintf("%s #%u sch_send %s\n",tintstr(),sender->id,
 534                         tintstr(send_time));
 535                 sender->Send();
 536                 sender->Reschedule();
 537             } else { // or close the channel
 538                 dprintf("%s #%u closed sendctrl\n",tintstr(),sender->id);
 539                 delete sender;
 540             }
 541
 542         } else {  // it's too early, wait
 543
 544             tint towait = min(limit,send_time) - NOW;
 545             dprintf("%s waiting %lliusec\n",tintstr(),towait);
 546             int rd = Datagram::Wait(socket_count,sockets,towait);
 547             if (rd!=INVALID_SOCKET) { // in meantime, received something
 548                 Channel* receiver = RecvDatagram(rd);
 549                 if (receiver) // receiver's state may have changed
 550                     receiver->Reschedule();
 551             }
 552             if (sender)  // get back to that later
 553                 send_queue.push(tintbin(send_time,sender->id));
 554
 555         }
 556
 557     } while (NOW<limit);
 558
 559 }
 560
 561
 562 void Channel::Reschedule () {
 563     next_send_time_ = NextSendTime();
 564     if (next_send_time_!=TINT_NEVER) {
 565         assert(next_send_time_<NOW+TINT_MIN);
 566         send_queue.push(tintbin(next_send_time_,id));
 567     } else
 568         send_queue.push(tintbin(NOW+TINT_MIN,id));
 569     dprintf("%s requeue #%u for %s\n",tintstr(),id,tintstr(next_send_time_));
 570 }