C# ArrayPool Example - Dot Net Perls

An example. Here we introduce a method called UseSharedArray that uses the ArrayPool generic type. We call UseSharedArray 3 times with a different number.

Generic

Part 1 We access the ArrayPool type and specify a type parameter int. We use the Shared property, and call Rent.

int

Part 2 The rented array always has a length of at least the value specified (in this program, 5). We use the array here.

Array Length

Part 3 We call Return() to allow the rented array to be used by another call. This enables reuse of allocated arrays.

using System; using System.Buffers; class Program { static void UseSharedArray(int x) { // Part 1: reference the ArrayPool and Rent an array. var shared = ArrayPool<int>.Shared; var rentedArray = shared.Rent(5); // Part 2: store values in rented array and print them. rentedArray[0] = 0; rentedArray[1] = 1 * x; rentedArray[2] = 2 * x; rentedArray[3] = 3 * x; rentedArray[4] = 4 * x; // ... Print integers. for (int i = 0; i < 5; i++) { Console.WriteLine("ARRAY {0}: {1}", x, rentedArray[i]); } // Part 3: return the rented array. shared.Return(rentedArray); } static void Main() { UseSharedArray(1); UseSharedArray(2); UseSharedArray(3); } }

ARRAY 1: 0 ARRAY 1: 1 ARRAY 1: 2 ARRAY 1: 3 ARRAY 1: 4 ARRAY 2: 0 ARRAY 2: 2 ARRAY 2: 4 ARRAY 2: 6 ARRAY 2: 8 ARRAY 3: 0 ARRAY 3: 3 ARRAY 3: 6 ARRAY 3: 9 ARRAY 3: 12

Static array. Sometimes we have simple array sharing requirements—only 1 array may be needed. We can just use a static array of a certain length.

static Array

using System; class Program { static int[] _shared = new int[5]; static void UseStaticArray(int x) { var rentedArray = _shared; rentedArray[0] = 0; rentedArray[1] = 1 * x; rentedArray[2] = 2 * x; rentedArray[3] = 3 * x; rentedArray[4] = 4 * x; // ... Print integers. for (int i = 0; i < 5; i++) { Console.WriteLine("ARRAY {0}: {1}", x, rentedArray[i]); } } static void Main() { UseStaticArray(1); UseStaticArray(2); UseStaticArray(3); } }

ARRAY 1: 0 ARRAY 1: 1 ARRAY 1: 2 ARRAY 1: 3 ARRAY 1: 4 ARRAY 2: 0 ARRAY 2: 2 ARRAY 2: 4 ARRAY 2: 6 ARRAY 2: 8 ARRAY 3: 0 ARRAY 3: 3 ARRAY 3: 6 ARRAY 3: 9 ARRAY 3: 12

Dot Net Perls is a collection of tested code examples. Pages are continually updated to stay current, with code correctness a top priority.

Sam Allen is passionate about computer languages. In the past, his work has been recommended by Apple and Microsoft and he has studied computers at a selective university in the United States.

This page was last updated on Dec 7, 2022 (simplify).

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