pike.git/ lib/ modules/ Sql.pmod/ pgsql_util.pmod

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2017-06-27

2017-06-27 10:30:15 by Stephen R. van den Berg <srb@cuci.nl>

pgsql: Disentangle portal-sync race for concurrent db-errors.

26:   private int clientsregistered;      constant emptyarray = ({}); + constant describenodata +  = (["datarowdesc":emptyarray,"datarowtypes":emptyarray]);   final multiset censoroptions=(<"use_ssl","force_ssl",    "cache_autoprepared_statements","reconnect","text_query","is_superuser",    "server_encoding","server_version","integer_datetimes",
193:       final void sendcmd(int mode,void|sql_result portal) {    Thread.MutexKey lock=realbuffer->shortmux->lock(); -  if(portal) +  if(portal) {    realbuffer->stashqueue->write(portal); -  +  if (mode == SYNCSEND) { +  add(PGSYNC); +  realbuffer->stashqueue->write(1); +  mode = SENDOUT; +  } +  }    realbuffer->stash->add(this); -  mode=mergemode(realbuffer,mode); +  mergemode(realbuffer, mode);    if(!--realbuffer->stashcount)    realbuffer->stashavail.signal();    lock=0;
300:    final bufcon|conxsess start(void|int waitforreal) {    Thread.MutexKey lock;    if(lock=(waitforreal?nostash->lock:nostash->trylock)(1)) { +  int mode;   #ifdef PG_DEBUGRACE    conxsess sess = conxsess(this);   #endif
307:    lock=shortmux->lock();    if(stashcount)    PT(stashavail.wait(lock)); -  add(stash); stash->clear(); -  foreach(stashqueue->try_read_array();;sql_result portal) -  queueup(portal); +  mode = getstash(KEEP);    lock=0; -  +  if (mode > KEEP) +  sendcmd(mode); // Force out stash to the server   #ifdef PG_DEBUGRACE    return sess;   #else
332:    return 0;    }    -  final void sendcmd(void|int mode, void|sql_result portal) { -  Thread.MutexKey lock; -  -  int emptystash() { -  int ret = 0; -  if (started) { -  lock = shortmux->lock(); +  private int getstash(int mode) {    if (sizeof(stash)) { -  add(stash); -  stash->clear(); -  foreach (stashqueue->try_read_array();; sql_result portal) +  add(stash); stash->clear(); +  foreach (stashqueue->try_read_array();; int|sql_result portal) +  if (intp(portal)) +  qportals->write(synctransact++); +  else    queueup(portal); -  ret = 1; -  } +     mode = mergemode(this, mode);    stashflushmode = KEEP;    } -  return ret; -  }; +  return mode; +  }    -  emptystash(); -  do { +  final void sendcmd(void|int mode, void|sql_result portal) { +  Thread.MutexKey lock;    if (portal)    queueup(portal); -  + unfinalised: +  do {    switch (mode) {    default: -  continue; +  break unfinalised;    case SYNCSEND:    PD("%d>Sync %d %d Queue\n",    socket->query_fd(), synctransact, ++queueoutidx);
366:    mode = SENDOUT;    break;    case FLUSHLOGSEND: -  PD("%d>%O %d Queue simplequery %d bytes\n", -  socket->query_fd(), portal._portalname, ++queueoutidx, sizeof(this)); +  PD("%d>%O %d Queue simplequery %d bytes\n", socket->query_fd(), +  portal._portalname, ++queueoutidx, sizeof(this));    mode = FLUSHSEND;    }    qportals->write(synctransact++); -  } while (!lock && emptystash()); +  } while(0); +  lock = shortmux->lock(); +  mode = getstash(mode);    catch {   outer:    do {
380:    PD("%d>Skip flush %d Queue %O\n",    socket->query_fd(), mode, (string)this);    break outer; +  case FLUSHLOGSEND:    case FLUSHSEND:    PD("Flush\n");    add(PGFLUSH); -  +  case SYNCSEND:    case SENDOUT:;    } -  if(!lock) -  lock=shortmux->lock(); +     if(towrite=sizeof(this)) {    PD("%d>Sendcmd %O\n",socket->query_fd(),((string)this)[..towrite-1]);    towrite-=output_to(socket,towrite);
1167:       final void _sendexecute(int fetchlimit,void|bufcon|conxsess plugbuffer) {    int flushmode; -  PD("Execute portal %O fetchlimit %d\n",_portalname,fetchlimit); +  PD("Execute portal %O fetchlimit %d transtype %d\n", _portalname, +  fetchlimit, transtype);    if(!plugbuffer)    plugbuffer=c->start(1);    CHAIN(plugbuffer)->add_int8('E')->add_hstring(({_portalname,0}), 4, 8)