BlockingCollection<T>.TryTakeFromAny Method (BlockingCollection<T>[], T)

.NET Framework (current version)

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Tries to remove an item from any one of the specified BlockingCollection<T> instances.

Namespace: System.Collections.Concurrent
Assembly: System (in System.dll)

Syntax

C++

public static int TryTakeFromAny(
	BlockingCollection<T>[] collections,
	out T item
)

Parameters

collections: Type: System.Collections.Concurrent.BlockingCollection<T>[]
The array of collections.

item: Type: T
The item removed from one of the collections.

Return Value

Type: System.Int32

The index of the collection in the collections array from which the item was removed, or -1 if an item could not be removed.

Exceptions

Exception	Condition
ObjectDisposedException	At least one of the BlockingCollection<T> instances has been disposed.
ArgumentNullException	The collections argument is null.
ArgumentOutOfRangeException	The count of collections is greater than the maximum size of 62 for STA and 63 for MTA.
ArgumentException	The collections argument is a 0-length array or contains a null element.
InvalidOperationException	At least one of the underlying collections was modified outside of its BlockingCollection<T> instance.

Remarks

A call to TryTakeFromAny may block until an item is available to be removed.

Examples

The following example shows how to use the BlockingCollection<T>.TryTakeFromAny method:

class FromToAnyDemo
{

    // Demonstrates:
    //      Bounded BlockingCollection<T>
    //      BlockingCollection<T>.TryAddToAny()
    //      BlockingCollection<T>.TryTakeFromAny()
    public static void BC_FromToAny()
    {
        BlockingCollection<int>[] bcs = new BlockingCollection<int>[2];
        bcs[0] = new BlockingCollection<int>(5); // collection bounded to 5 items
        bcs[1] = new BlockingCollection<int>(5); // collection bounded to 5 items

        // Should be able to add 10 items w/o blocking
        int numFailures = 0;
        for (int i = 0; i < 10; i++)
        {
            if (BlockingCollection<int>.TryAddToAny(bcs, i) == -1) numFailures++;
        }
        Console.WriteLine("TryAddToAny: {0} failures (should be 0)", numFailures);

        // Should be able to retrieve 10 items
        int numItems = 0;
        int item;
        while (BlockingCollection<int>.TryTakeFromAny(bcs, out item) != -1) numItems++;
        Console.WriteLine("TryTakeFromAny: retrieved {0} items (should be 10)", numItems);
    }
}

Version Information

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone
Available since 8.1