Example
Used for the RAII style acquiring of try locks, timed try locks and recursive locks.
std::unique_lock allows for exclusive ownership of mutexes.
std::shared_lock allows for shared ownership of mutexes. Several threads can hold std::shared_locks on a std::shared_mutex. Available from C++ 14.
std::lock_guard is a lightweight alternative to std::unique_lock and std::shared_lock.
#include <unordered_map>
#include <mutex>
#include <shared_mutex>
#include <thread>
#include <string>
#include <iostream>
class PhoneBook {
public:
std::string getPhoneNo( const std::string & name )
{
std::shared_lock<std::shared_timed_mutex> l(_protect);
auto it = _phonebook.find( name );
if ( it != _phonebook.end() )
return (*it).second;
return "";
}
void addPhoneNo ( const std::string & name, const std::string & phone )
{
std::unique_lock<std::shared_timed_mutex> l(_protect);
_phonebook[name] = phone;
}
std::shared_timed_mutex _protect;
std::unordered_map<std::string,std::string> _phonebook;
};
