```
bitcoind -par=1
```

Excerpt from the `debug.log`:

```
Using 0 threads for script verification
```

Zero? I guess not ;)
#include <attributes.h>
#include <cerrno>
#include <signal.h>
#include <sys/stat.h>
#endif
#include <boost/algorithm/string/classification.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <boost/algorithm/string/split.hpp>
#include <boost/thread.hpp>
#if ENABLE_ZMQ
#include <zmq/zmqabstractnotifier.h>
#include <zmq/zmqnotificationinterface.h>
#include <zmq/zmqrpc.h>
#endif
static bool fFeeEstimatesInitialized = false;
static const bool DEFAULT_PROXYRANDOMIZE = true;
static const bool DEFAULT_REST_ENABLE = false;
static const bool DEFAULT_STOPAFTERBLOCKIMPORT = false;
static constexpr int DUMP_BANS_INTERVAL = 60 * 15;
#ifdef WIN32
#define MIN_CORE_FILEDESCRIPTORS 0
#else
#define MIN_CORE_FILEDESCRIPTORS 150
#endif
static const char* FEE_ESTIMATES_FILENAME="fee_estimates.dat";
/**
 * The PID file facilities.
 */
static const char* BITCOIN_PID_FILENAME = "bitcoind.pid";
static fs::path GetPidFile()