DistributedMutex.cs

public class DistributedMutex {
   	private readonly string key;
   	private readonly string storageConnectionString;
   	private readonly string storageContainerName;
   	private CloudBlobClient blobClient;
   	private string leaseId;
 
   	public DistributedMutex(string storageConnectionString, string storageContainerName, string key)
   	{
         	this.key = key;
         	this.storageConnectionString = storageConnectionString;
         	this.storageContainerName = storageContainerName;
   	}
 
   	/// <summary>
   	///     Acquires a lease blob.
   	/// </summary>
   	public async Task AcquireAsync()
   	{
         	var storageAccount = CloudStorageAccount.Parse(storageConnectionString);
         	blobClient = storageAccount.CreateCloudBlobClient();
 
         	var containerReference = blobClient.GetContainerReference(storageContainerName);
         	await containerReference.CreateIfNotExistsAsync();
         	var blobReference = containerReference.GetBlockBlobReference(key);
 
         	if (!await blobReference.ExistsAsync()) await blobReference.UploadTextAsync(string.Empty);
 
         	try {
                	leaseId = await blobReference.AcquireLeaseAsync(TimeSpan.FromSeconds(60));
         	}
 
         	catch (StorageException ex) {
                	Console.WriteLine("Error while acquiring an a job lease.");
                	Console.WriteLine(ex.Message);
 
                	if (ex.RequestInformation.HttpStatusCode == (int)HttpStatusCode.Conflict) throw new InvalidOperationException($"Another job is already running for {key}.");
 
                	throw;
         	}
   	}
 
 
   	/// <summary>
   	///     Releases a lease blob.
   	/// </summary>  	
   	public async Task ReleaseLockAsync()
   	{                      	
         	var containerReference = blobClient.GetContainerReference(storageContainerName);
         	await containerReference.CreateIfNotExistsAsync();
         	var blobReference = containerReference.GetBlockBlobReference(key);
 
         	await blobReference.ReleaseLeaseAsync(new AccessCondition {
                	LeaseId = leaseId
         	});
   	}
 
   	/// <summary>
   	///     Renews the lease.
   	/// </summary>  	
   	public async Task RenewAsync()
   	{  	
         	var containerClientReference = blobClient.GetContainerReference(storageContainerName);
         	await containerClientReference.CreateIfNotExistsAsync();
         	var blobReference = containerClientReference.GetBlockBlobReference(key);
 
         	await blobReference.RenewLeaseAsync(new AccessCondition {
                	LeaseId = leaseId
         	});
   	}
}