read_write_lock_guard.h

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#ifndef READ_WRITE_LOCK_GUARD_INCLUDED
#define READ_WRITE_LOCK_GUARD_INCLUDED
 
#include "sentry.h"  // raii::Sentry
 
/**
  Generic sentry class for read locking.
  For the given callable type the class assumes a read lock can be acquired
  with rdlock() in the constructor.
  On deletion the class will unlock with an unlock() invocation
 */
template <typename Rd_lockable>
class Rdlock_guard : public raii::Sentry<> {
 public:
  /**
   Constructor for the class that creates a sentry that will unlock
   the callable object on destruction and then read locks the object.
 
   @param lock The callable object to be locked/unlocked
 */
  Rdlock_guard(Rd_lockable &lock)
      : Sentry{[&lock]() -> void { lock.unlock(); }} {
    lock.rdlock();
  }
  virtual ~Rdlock_guard() override = default;
};
 
/**
  Generic sentry class for write locking.
  For the given callable type the class assumes a write lock can be acquired
  with wrlock() in the constructor.
  On deletion the class will unlock with an unlock() invocation
 */
template <typename Wr_lockable>
class Wrlock_guard : public raii::Sentry<> {
 public:
  /**
    Constructor for the class that creates a sentry that will unlock
    the callable object on destruction and then write locks the object.
 
    @param lock The callable object to be locked/unlocked
  */
  Wrlock_guard(Wr_lockable &lock)
      : Sentry{[&lock]() -> void { lock.unlock(); }} {
    lock.wrlock();
  }
  virtual ~Wrlock_guard() override = default;
};
 
#endif  // READ_WRITE_LOCK_GUARD_INCLUDED