Parallel http requests in Unity

gistfile1.cs

private IEnumerator ProcessRequests()
{
	if(isProcessing || taskQueue.Count == 0){
		yield break;
	}

	isProcessing = true;
	//get a temp variable, otherwise we could be stuck in an infinite-loop (offline scenario)
	int itemsToProcess = taskQueue.Count;
	while(itemsToProcess > 0){
		ApiRequest request = taskQueue.Peek();
		if((!request.FutureProcessDate.HasValue) || (request.FutureProcessDate.Value < DateTime.UtcNow))
		{
			//not need to wait here, so don't yeild return
			StartCoroutine( DoRequest(taskQueue.Dequeue()) );
		}
		itemsToProcess --;
	}
	isProcessing = false;
}

private IEnumerator DoRequest(ApiRequest request)
{
	request.Attempts ++;
	Logger.Log(LogType.Log, "Starting Request (Attempt {1}) {0}", request.Url, request.Attempts);
	WWW httpRequest = new WWW(request.Url);

	//yield control back to the caller so that we're not waiting for the download to complete,
	//will resume the call when the web call completes
	yield return httpRequest;

	if(httpRequest.isDone && string.IsNullOrEmpty(httpRequest.error))
	{
		if(request.RequestCompleteHandler != null){
			request.RequestCompleteHandler(request.Url, httpRequest);
		}
		LocalCache.instance.UpdateLastEventEpochTime(DateTime.UtcNow);
		Logger.Log(LogType.Log, "Request succeeded");

	} else {
		Logger.Log(LogType.Warning, "Request failed with Error: {0}", httpRequest.error);

		if(request.ShouldPersist && request.Attempts < maxRetryCount){
			double retryMinutes = Math.Pow((double)futureTaskIncrementMinutes, (double)request.Attempts);
			request.FutureProcessDate = DateTime.UtcNow.AddMinutes(retryMinutes);
			Logger.Log(LogType.Log, "Request failed, but retrying in {0} minutes.", retryMinutes);
			taskQueue.Enqueue(request);
		} else {
			Logger.Log(LogType.Log, "Request failed, not retrying.");
		}
	}
}