dbtuxscan.cpp

mysql-5.0.22.tar.gz源码包

      scan.m_state = ScanOp::Aborting;
      return;
    }
    if (scan.m_state == ScanOp::Locked) {
      jam();
      ndbrequire(scan.m_accLockOp != RNIL);
      AccLockReq* const lockReq = (AccLockReq*)signal->getDataPtrSend();
      lockReq->returnCode = RNIL;
      lockReq->requestInfo = AccLockReq::Unlock;
      lockReq->accOpPtr = scan.m_accLockOp;
      EXECUTE_DIRECT(DBACC, GSN_ACC_LOCKREQ, signal, AccLockReq::UndoSignalLength);
      jamEntry();
      ndbrequire(lockReq->returnCode == AccLockReq::Success);
      scan.m_accLockOp = RNIL;
    }
    scan.m_state = ScanOp::Aborting;
    scanClose(signal, scanPtr);
    return;
  case NextScanReq::ZSCAN_NEXT_ABORT:
    jam();
  default:
    jam();
    ndbrequire(false);
    break;
  }
  // start looking for next scan result
  AccCheckScan* checkReq = (AccCheckScan*)signal->getDataPtrSend();
  checkReq->accPtr = scanPtr.i;
  checkReq->checkLcpStop = AccCheckScan::ZNOT_CHECK_LCP_STOP;
  EXECUTE_DIRECT(DBTUX, GSN_ACC_CHECK_SCAN, signal, AccCheckScan::SignalLength);
  jamEntry();
}

void
Dbtux::execACC_CHECK_SCAN(Signal* signal)
{
  jamEntry();
  const AccCheckScan reqCopy = *(const AccCheckScan*)signal->getDataPtr();
  const AccCheckScan* const req = &reqCopy;
  ScanOpPtr scanPtr;
  scanPtr.i = req->accPtr;
  c_scanOpPool.getPtr(scanPtr);
  ScanOp& scan = *scanPtr.p;
  Frag& frag = *c_fragPool.getPtr(scan.m_fragPtrI);
#ifdef VM_TRACE
  if (debugFlags & DebugScan) {
    debugOut << "ACC_CHECK_SCAN scan " << scanPtr.i << " " << scan << endl;
  }
#endif
  if (req->checkLcpStop == AccCheckScan::ZCHECK_LCP_STOP) {
    jam();
    signal->theData[0] = scan.m_userPtr;
    signal->theData[1] = true;
    EXECUTE_DIRECT(DBLQH, GSN_CHECK_LCP_STOP, signal, 2);
    jamEntry();
    return;   // stop
  }
  if (scan.m_lockwait) {
    jam();
    // LQH asks if we are waiting for lock and we tell it to ask again
    const TreeEnt ent = scan.m_scanEnt;
    NextScanConf* const conf = (NextScanConf*)signal->getDataPtrSend();
    conf->scanPtr = scan.m_userPtr;
    conf->accOperationPtr = RNIL;       // no tuple returned
    conf->fragId = frag.m_fragId | ent.m_fragBit;
    unsigned signalLength = 3;
    // if TC has ordered scan close, it will be detected here
    sendSignal(scan.m_userRef, GSN_NEXT_SCANCONF,
        signal, signalLength, JBB);
    return;     // stop
  }
  if (scan.m_state == ScanOp::First) {
    jam();
    // search is done only once in single range scan
    scanFirst(scanPtr);
#ifdef VM_TRACE
    if (debugFlags & DebugScan) {
      debugOut << "First scan " << scanPtr.i << " " << scan << endl;
    }
#endif
  }
  if (scan.m_state == ScanOp::Next) {
    jam();
    // look for next
    scanNext(scanPtr, false);
  }
  // for reading tuple key in Current or Locked state
  Data pkData = c_dataBuffer;
  unsigned pkSize = 0; // indicates not yet done
  if (scan.m_state == ScanOp::Current) {
    // found an entry to return
    jam();
    ndbrequire(scan.m_accLockOp == RNIL);
    if (! scan.m_readCommitted) {
      jam();
      const TreeEnt ent = scan.m_scanEnt;
      // read tuple key
      readTablePk(frag, ent, pkData, pkSize);
      // get read lock or exclusive lock
      AccLockReq* const lockReq = (AccLockReq*)signal->getDataPtrSend();
      lockReq->returnCode = RNIL;
      lockReq->requestInfo =
        scan.m_lockMode == 0 ? AccLockReq::LockShared : AccLockReq::LockExclusive;
      lockReq->accOpPtr = RNIL;
      lockReq->userPtr = scanPtr.i;
      lockReq->userRef = reference();
      lockReq->tableId = scan.m_tableId;
      lockReq->fragId = frag.m_fragId | ent.m_fragBit;
      lockReq->fragPtrI = frag.m_accTableFragPtrI[ent.m_fragBit];
      const Uint32* const buf32 = static_cast<Uint32*>(pkData);
      const Uint64* const buf64 = reinterpret_cast<const Uint64*>(buf32);
      lockReq->hashValue = md5_hash(buf64, pkSize);
      lockReq->tupAddr = getTupAddr(frag, ent);
      lockReq->transId1 = scan.m_transId1;
      lockReq->transId2 = scan.m_transId2;
      // execute
      EXECUTE_DIRECT(DBACC, GSN_ACC_LOCKREQ, signal, AccLockReq::LockSignalLength);
      jamEntry();
      switch (lockReq->returnCode) {
      case AccLockReq::Success:
        jam();
        scan.m_state = ScanOp::Locked;
        scan.m_accLockOp = lockReq->accOpPtr;
#ifdef VM_TRACE
        if (debugFlags & DebugScan) {
          debugOut << "Lock immediate scan " << scanPtr.i << " " << scan << endl;
        }
#endif
        break;
      case AccLockReq::IsBlocked:
        jam();
        // normal lock wait
        scan.m_state = ScanOp::Blocked;
        scan.m_lockwait = true;
        scan.m_accLockOp = lockReq->accOpPtr;
#ifdef VM_TRACE
        if (debugFlags & DebugScan) {
          debugOut << "Lock wait scan " << scanPtr.i << " " << scan << endl;
        }
#endif
        // LQH will wake us up
        signal->theData[0] = scan.m_userPtr;
        signal->theData[1] = true;
        EXECUTE_DIRECT(DBLQH, GSN_CHECK_LCP_STOP, signal, 2);
        jamEntry();
        return;  // stop
        break;
      case AccLockReq::Refused:
        jam();
        // we cannot see deleted tuple (assert only)
        ndbassert(false);
        // skip it
        scan.m_state = ScanOp::Next;
        signal->theData[0] = scan.m_userPtr;
        signal->theData[1] = true;
        EXECUTE_DIRECT(DBLQH, GSN_CHECK_LCP_STOP, signal, 2);
        jamEntry();
        return;  // stop
        break;
      case AccLockReq::NoFreeOp:
        jam();
        // max ops should depend on max scans (assert only)
        ndbassert(false);
        // stay in Current state
        scan.m_state = ScanOp::Current;
        signal->theData[0] = scan.m_userPtr;
        signal->theData[1] = true;
        EXECUTE_DIRECT(DBLQH, GSN_CHECK_LCP_STOP, signal, 2);
        jamEntry();
        return;  // stop
        break;
      default:
        ndbrequire(false);
        break;
      }
    } else {
      scan.m_state = ScanOp::Locked;
    }
  }
  if (scan.m_state == ScanOp::Locked) {
    // we have lock or do not need one
    jam();
    // read keys if not already done (uses signal)
    const TreeEnt ent = scan.m_scanEnt;
    // conf signal
    NextScanConf* const conf = (NextScanConf*)signal->getDataPtrSend();
    conf->scanPtr = scan.m_userPtr;
    // the lock is passed to LQH
    Uint32 accLockOp = scan.m_accLockOp;
    if (accLockOp != RNIL) {
      scan.m_accLockOp = RNIL;
      // remember it until LQH unlocks it
      addAccLockOp(scan, accLockOp);
    } else {
      ndbrequire(scan.m_readCommitted);
      // operation RNIL in LQH would signal no tuple returned
      accLockOp = (Uint32)-1;
    }
    conf->accOperationPtr = accLockOp;
    conf->fragId = frag.m_fragId | ent.m_fragBit;
    conf->localKey[0] = getTupAddr(frag, ent);
    conf->localKey[1] = 0;
    conf->localKeyLength = 1;
    unsigned signalLength = 6;
    // add key info
    if (! scan.m_readCommitted) {
      sendSignal(scan.m_userRef, GSN_NEXT_SCANCONF,
          signal, signalLength, JBB);
    } else {
      Uint32 blockNo = refToBlock(scan.m_userRef);
      EXECUTE_DIRECT(blockNo, GSN_NEXT_SCANCONF, signal, signalLength);
    }
    // next time look for next entry
    scan.m_state = ScanOp::Next;
    return;
  }
  // XXX in ACC this is checked before req->checkLcpStop
  if (scan.m_state == ScanOp::Last ||
      scan.m_state == ScanOp::Invalid) {
    jam();
    NextScanConf* const conf = (NextScanConf*)signal->getDataPtrSend();
    conf->scanPtr = scan.m_userPtr;
    conf->accOperationPtr = RNIL;
    conf->fragId = RNIL;
    unsigned signalLength = 3;
    sendSignal(scanPtr.p->m_userRef, GSN_NEXT_SCANCONF,
        signal, signalLength, JBB);
    return;
  }
  ndbrequire(false);
}

/*
 * Lock succeeded (after delay) in ACC.  If the lock is for current
 * entry, set state to Locked.  If the lock is for an entry we were
 * moved away from, simply unlock it.  Finally, if we are closing the
 * scan, do nothing since we have already sent an abort request.
 */
void
Dbtux::execACCKEYCONF(Signal* signal)
{
  jamEntry();
  ScanOpPtr scanPtr;
  scanPtr.i = signal->theData[0];
  c_scanOpPool.getPtr(scanPtr);
  ScanOp& scan = *scanPtr.p;
#ifdef VM_TRACE
  if (debugFlags & DebugScan) {
    debugOut << "Lock obtained scan " << scanPtr.i << " " << scan << endl;
  }
#endif
  ndbrequire(scan.m_lockwait && scan.m_accLockOp != RNIL);
  scan.m_lockwait = false;
  if (scan.m_state == ScanOp::Blocked) {
    // the lock wait was for current entry
    jam();
    scan.m_state = ScanOp::Locked;
    // LQH has the ball
    return;
  }
  if (scan.m_state != ScanOp::Aborting) {
    // we were moved, release lock
    jam();
    AccLockReq* const lockReq = (AccLockReq*)signal->getDataPtrSend();
    lockReq->returnCode = RNIL;
    lockReq->requestInfo = AccLockReq::Unlock;
    lockReq->accOpPtr = scan.m_accLockOp;
    EXECUTE_DIRECT(DBACC, GSN_ACC_LOCKREQ, signal, AccLockReq::UndoSignalLength);
    jamEntry();
    ndbrequire(lockReq->returnCode == AccLockReq::Success);
    scan.m_accLockOp = RNIL;
    // LQH has the ball
    return;
  }
  // lose the lock
  scan.m_accLockOp = RNIL;
  // continue at ACC_ABORTCONF
}

/*
 * Lock failed (after delay) in ACC.  Probably means somebody ahead of
 * us in lock queue deleted the tuple.
 */
void
Dbtux::execACCKEYREF(Signal* signal)
{
  jamEntry();
  ScanOpPtr scanPtr;
  scanPtr.i = signal->theData[0];
  c_scanOpPool.getPtr(scanPtr);
  ScanOp& scan = *scanPtr.p;
#ifdef VM_TRACE
  if (debugFlags & DebugScan) {
    debugOut << "Lock refused scan " << scanPtr.i << " " << scan << endl;
  }
#endif
  ndbrequire(scan.m_lockwait && scan.m_accLockOp != RNIL);
  scan.m_lockwait = false;
  if (scan.m_state != ScanOp::Aborting) {
    jam();
    // release the operation
    AccLockReq* const lockReq = (AccLockReq*)signal->getDataPtrSend();
    lockReq->returnCode = RNIL;
    lockReq->requestInfo = AccLockReq::Abort;
    lockReq->accOpPtr = scan.m_accLockOp;
    EXECUTE_DIRECT(DBACC, GSN_ACC_LOCKREQ, signal, AccLockReq::UndoSignalLength);
    jamEntry();
    ndbrequire(lockReq->returnCode == AccLockReq::Success);
    scan.m_accLockOp = RNIL;
    // scan position should already have been moved (assert only)
    if (scan.m_state == ScanOp::Blocked) {
      jam();
      ndbassert(false);
      scan.m_state = ScanOp::Next;
    }
    // LQH has the ball
    return;
  }
  // lose the lock
  scan.m_accLockOp = RNIL;
  // continue at ACC_ABORTCONF
}

/*
 * Received when scan is closing.  This signal arrives after any
 * ACCKEYCON or ACCKEYREF which may have been in job buffer.
 */
void
Dbtux::execACC_ABORTCONF(Signal* signal)
{
  jamEntry();
  ScanOpPtr scanPtr;
  scanPtr.i = signal->theData[0];
  c_scanOpPool.getPtr(scanPtr);
  ScanOp& scan = *scanPtr.p;
#ifdef VM_TRACE
  if (debugFlags & DebugScan) {
    debugOut << "ACC_ABORTCONF scan " << scanPtr.i << " " << scan << endl;
  }
#endif
  ndbrequire(scan.m_state == ScanOp::Aborting);
  // most likely we are still in lock wait
  if (scan.m_lockwait) {
    jam();
    scan.m_lockwait = false;
    scan.m_accLockOp = RNIL;
  }
  scanClose(signal, scanPtr);