void SessionManagerServer::saveSMTxnIDAndState()
{
// caller holds the lock
scoped_ptr<IDBDataFile> txnidfp(IDBDataFile::open(
IDBPolicy::getType(txnidFilename.c_str(), IDBPolicy::WRITEENG),
txnidFilename.c_str(), "wb", 0));
if (!txnidfp) {
perror("SessionManagerServer(): open");
throw runtime_error("SessionManagerServer: Could not open the transaction ID file");
}
int filedata[2];
filedata[0] = _verID;
filedata[1] = _sysCatVerID;
int err = txnidfp->write(filedata, 8);
if (err < 0) {
perror("SessionManagerServer::newTxnID(): write(verid)");
throw runtime_error("SessionManagerServer::newTxnID(): write(verid) failed");
}
uint32_t lSystemState = systemState;
// We don't save the pending flags, the force flag or the ready flag.
lSystemState &= ~(SS_READY | SS_SUSPEND_PENDING | SS_SHUTDOWN_PENDING | SS_FORCE);
err = txnidfp->write(&lSystemState, sizeof(int));
if (err < 0) {
perror("SessionManagerServer::saveSystemState(): write(systemState)");
throw runtime_error("SessionManagerServer::saveSystemState(): write(systemState) failed");
}
txnidfp->flush();
}
void SessionManagerServer::loadState()
{
int lastTxnID;
int err;
int lastSysCatVerId;
again:
// There are now 3 pieces of info stored in the txnidfd file: last
// transaction id, last system catalog version id, and the
// system state flags. All these values are stored in shared, an
// instance of struct Overlay.
// If we fail to read a full four bytes for any value, then the
// value isn't in the file, and we start with the default.
if (!IDBPolicy::useHdfs())
{
// Last transaction id
lseek(txnidfd, 0, SEEK_SET);
err = read(txnidfd, &lastTxnID, 4);
if (err < 0 && errno != EINTR)
{
perror("Sessionmanager::initSegment(): read");
throw runtime_error("SessionManagerServer: read failed, aborting");
}
else if (err < 0)
goto again;
else if (err == sizeof(int))
_verID = lastTxnID;
// last system catalog version id
err = read(txnidfd, &lastSysCatVerId, 4);
if (err < 0 && errno != EINTR)
{
perror("Sessionmanager::initSegment(): read");
throw runtime_error("SessionManagerServer: read failed, aborting");
}
else if (err < 0)
goto again;
else if (err == sizeof(int))
_sysCatVerID = lastSysCatVerId;
// System state. Contains flags regarding the suspend state of the system.
err = read(txnidfd, &systemState, 4);
if (err < 0 && errno == EINTR)
{
goto again;
}
else if (err == sizeof(int))
{
// Turn off the pending and force flags. They make no sense for a clean start.
// Turn off the ready flag. DMLProc will set it back on when
// initialized.
systemState &=
~(SS_READY | SS_QUERY_READY | SS_SUSPEND_PENDING | SS_SHUTDOWN_PENDING | SS_ROLLBACK | SS_FORCE);
}
else
{
// else no problem. System state wasn't saved. Might be an upgraded system.
systemState = 0;
}
}
else if (IDBPolicy::exists(txnidFilename.c_str()))
{
scoped_ptr<IDBDataFile> txnidfp(IDBDataFile::open(
IDBPolicy::getType(txnidFilename.c_str(),
IDBPolicy::WRITEENG),
txnidFilename.c_str(), "rb", 0));
if (!txnidfp)
{
perror("SessionManagerServer(): open");
throw runtime_error("SessionManagerServer: Could not open the transaction ID file");
}
// Last transaction id
txnidfp->seek(0, SEEK_SET);
err = txnidfp->read(&lastTxnID, 4);
if (err < 0 && errno != EINTR)
{
perror("Sessionmanager::initSegment(): read");
throw runtime_error("SessionManagerServer: read failed, aborting");
}
else if (err < 0)
goto again;
else if (err == sizeof(int))
_verID = lastTxnID;
// last system catalog version id
err = txnidfp->read(&lastSysCatVerId, 4);
if (err < 0 && errno != EINTR)
{
perror("Sessionmanager::initSegment(): read");
throw runtime_error("SessionManagerServer: read failed, aborting");
}
else if (err < 0)
goto again;
else if (err == sizeof(int))
_sysCatVerID = lastSysCatVerId;
// System state. Contains flags regarding the suspend state of the system.
err = txnidfp->read(&systemState, 4);
if (err < 0 && errno == EINTR)
{
goto again;
}
else if (err == sizeof(int))
{
// Turn off the pending and force flags. They make no sense for a clean start.
// Turn off the ready flag. DMLProc will set it back on when
// initialized.
systemState &=
~(SS_READY | SS_QUERY_READY | SS_SUSPEND_PENDING | SS_SHUTDOWN_PENDING | SS_ROLLBACK | SS_FORCE);
}
else
{
// else no problem. System state wasn't saved. Might be an upgraded system.
systemState = 0;
}
}
}
