Method AsSafeEnumerable
AsSafeEnumerable<TKey, TValue>(ConcurrentDictionary<TKey, TValue>)
Wraps a ConcurrentDictionary<TKey, TValue> in an IEnumerable<T> that is safe to pass to consumers which may otherwise corrupt or fail when the dictionary is modified concurrently during enumeration.
Declaration
public static IEnumerable<KeyValuePair<TKey, TValue>> AsSafeEnumerable<TKey, TValue>(this ConcurrentDictionary<TKey, TValue> dictionary) where TKey : notnullParameters
| Type | Name | Description |
|---|---|---|
| ConcurrentDictionary<TKey, TValue> | dictionary | The dictionary to wrap. |
Returns
| Type | Description |
|---|---|
| IEnumerable<KeyValuePair<TKey, TValue>> | An IEnumerable<T> that enumerates the key-value pairs in the dictionary. |
Type Parameters
| Name | Description |
|---|---|
| TKey | The type of the keys in the dictionary. |
| TValue | The type of the values in the dictionary. |
Remarks
While directly enumerating a ConcurrentDictionary<TKey, TValue> is safe even if it is modified concurrently, many BCL methods that operate on IEnumerable<T> attempt to cast it to ICollection<T> (which ConcurrentDictionary<TKey, TValue> implements) as an optimization. That optimization can cause silent corruption or exceptions if the dictionary is modified concurrently.
Wrapping the dictionary with this method hides the ICollection<T> implementation so it can be safely passed to any method that accepts an IEnumerable<T>, such as LINQ operators and collection constructors, without risking corruption or exceptions due to concurrent modifications.