ThreadSafeStore<TKey, TValue>
using System;
using System.Collections.Generic;
using System.Threading;
namespace Newtonsoft.Json.Utilities
{
internal class ThreadSafeStore<TKey, TValue>
{
private readonly object _lock = new object();
private Dictionary<TKey, TValue> _store;
private readonly Func<TKey, TValue> _creator;
public ThreadSafeStore(Func<TKey, TValue> creator)
{
ValidationUtils.ArgumentNotNull(creator, "creator");
_creator = creator;
_store = new Dictionary<TKey, TValue>();
}
public TValue Get(TKey key)
{
if (!_store.TryGetValue(key, out TValue value))
return AddValue(key);
return value;
}
private TValue AddValue(TKey key)
{
TValue val = _creator(key);
lock (_lock) {
if (_store == null) {
_store = new Dictionary<TKey, TValue>();
_store[key] = val;
} else {
if (_store.TryGetValue(key, out TValue value))
return value;
Dictionary<TKey, TValue> dictionary = new Dictionary<TKey, TValue>(_store);
dictionary[key] = val;
Thread.MemoryBarrier();
_store = dictionary;
}
return val;
}
}
}
}