osquery-1/osquery/registry/init_registry.h

// Copyright 2004-present Facebook. All Rights Reserved.

#ifndef OSQUERY_REGISTRY_INIT_REGISTRY_H
#define OSQUERY_REGISTRY_INIT_REGISTRY_H

#include <boost/noncopyable.hpp>

#include "osquery/registry/registry_template.h"

namespace osquery {

class InitRegistry : public RegistryTemplate<> {
 public:
  /**
   * Singleton.
   */
  static InitRegistry& get() {
    static InitRegistry instance; // Thread-safe.
    return instance;
  }

 private:
  InitRegistry() {}
};

/**
 * The most standard way to register an init func is to use this class
 * as a static instance in some file to ensure the function gets called
 * once main actually begins.
 *
 * Examples:
 *
 *   static RegisterInitFunc reg1(&setupFancyTable);
 *   static RegisterInitFunc reg2(std::bind(&setupSomething, 10, 15));
 *   static RegisterInitFunc reg3([] { setupSomethingElse(20, 25); });
 *
 */
struct RegisterInitFunc : private boost::noncopyable {
  explicit RegisterInitFunc(InitRegistry::Func func,
                            int priority = InitRegistry::kDefaultPriority) {
    InitRegistry::get().registerFunc(std::move(func), priority);
  }
};

} // namespace osquery

#endif /* OSQUERY_REGISTRY_INIT_REGISTRY_H */