/// <summary>
/// Gets the stored value associated with the specified key or store a new value
/// generated by the provided factory function and return it.
/// If the value factory function is called to create a new item, a lock is aquired to supress
/// multiple call to the factory function for the specified key (calls to others keys are not blocked).
/// If the lock times out (i.e. the factory takes more waitTimeout to create then new instance), the default value for the type is returned.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="valueFactory">The value factory function.</param>
/// <param name="waitTimeoutMilliseconds">The wait timeout milliseconds.</param>
/// <returns>Stored value for the key or default value if not found</returns>
public static T GetOrSyncAdd(string key, Func <string, T> valueFactory, int waitTimeoutMilliseconds)
{
if (String.IsNullOrEmpty(key))
{
return(default(T));
}
CachedItem item;
if (!m_cacheMap.TryGetValue(key, out item))
{
// create a lock for this key
using (var padlock = new NamedLock(key))
{
if (padlock.Enter(waitTimeoutMilliseconds))
{
return(GetOrAdd(key, valueFactory));
}
else
{
return(default(T));
}
}
}
return(item.Data);
}
/// <summary>
/// Creates a new instance and tries to aquire a lock.
/// </summary>
/// <param name="key">The named lock key.</param>
/// <param name="waitTimeoutMilliseconds">The wait timeout milliseconds.</param>
public static NamedLock CreateAndEnter(string key, int waitTimeoutMilliseconds)
{
NamedLock item;
item = new NamedLock(key);
item.Enter(waitTimeoutMilliseconds);
return(item);
}
/// <summary>
/// Creates a new instance and tries to aquire a lock.
/// </summary>
/// <param name="key">The named lock key.</param>
public static NamedLock CreateAndEnter(string key)
{
NamedLock item;
item = new NamedLock(key);
item.Enter();
return(item);
}