AArnott

using System;
using System.Numerics;
using System.Security.Cryptography;
using System.Text;
using Xunit;

public class RSA
{
    [Fact]
    public void WikipediaExample()

AArnott

#ref System.Numerics.dll

var rsa = new RSACryptoServiceProvider(512);
var parameters = rsa.ExportParameters(true);

var p = new BigInteger(parameters.P.Reverse().ToArray());
var q = new BigInteger(parameters.Q.Reverse().ToArray());
var n = p * q;
Assert.Equal(parameters.Modulus.Reverse().ToArray(), n.ToByteArray());

AArnott

using Microsoft.VisualStudio.Threading;

public class ThreadSafeDictionary<K, V>
{
  private readonly TaskScheduler exclusiveScheduler = new ConcurrentExclusiveSchedulerPair().ExclusiveScheduler;
  private readonly Dictionary<K, V> inner = new Dictionary<K, V>();

  public async Task AddThenRemoveAsync(K key, V value, CancellationToken cancellationToken = default(CancellationToken)) {
    await this.exclusiveScheduler; // Enabled by Microsoft.VisualStudio.Threading extension method.
    cancellationToken.ThrowIfCancellationRequested();

AArnott

using Microsoft.VisualStudio.Threading; // From the Microsoft.VisualStudio.Threading NuGet package

public class ThreadSafeDictionary<K, V>
{
  private readonly AsyncSemaphore semaphore = new AsyncSemaphore(1);
  private readonly Dictionary<K, V> inner = new Dictionary<K, V>();

  public async Task AddThenRemoveAsync(K key, V value, CancellationToken cancellationToken = default(CancellationToken)) {
    using (await this.semaphore.EnterAsync(cancellationToken)) {
      this.inner.Add(key, value);

AArnott

public class ThreadSafeDictionary<K, V>
{
  private readonly SemaphoreSlim semaphore = new SemaphoreSlim(1);
  private readonly Dictionary<K, V> inner = new Dictionary<K, V>();

  public async Task AddThenRemoveAsync(K key, V value, CancellationToken cancellationToken = default(CancellationToken)) {
    await this.semaphore.WaitAsync(cancellationToken);
    try {
      this.inner.Add(key, value);
      await Task.Delay(50); // still holding semaphore, so no one can get it!

AArnott

public class ThreadSafeDictionary<K, V>
{
  private readonly TaskScheduler exclusiveScheduler = new ConcurrentExclusiveSchedulerPair().ExclusiveScheduler;
  private readonly Dictionary<K, V> inner = new Dictionary<K, V>();

  public Task AddThenRemoveAsync(K key, V value, CancellationToken cancellationToken = default(CancellationToken)) {
    return TaskScheduler.Factory.StartNew(
      async delegate {
        this.inner.Add(key, value);
        await Task.Delay(50);

AArnott

public class ThreadSafeDictionary<K, V>
{
  private readonly TaskScheduler exclusiveScheduler = new ConcurrentExclusiveSchedulerPair().ExclusiveScheduler;
  private readonly Dictionary<K, V> inner = new Dictionary<K, V>();

  public Task AddAsync(K key, V value, CancellationToken cancellationToken = default(CancellationToken)) {
    return TaskScheduler.Factory.StartNew(
      () => this.inner.Add(key, value),
      cancellationToken,
      TaskCreationOptions.None,

AArnott

public class ThreadSafeDictionary<K, V>
{
  private readonly SemaphoreSlim semaphore = new SemaphoreSlim(1);
  private readonly Dictionary<K, V> inner = new Dictionary<K, V>();

  public async Task AddAsync(K key, V value, CancellationToken cancellationToken = default(CancellationToken)) {
    await this.semaphore.WaitAsync(cancellationToken);
    try {
      this.inner.Add(key, value);
    } finally {

AArnott

using System;
using System.Threading;
using System.Threading.Tasks;

class Program
{
    static void Main()
    {
        var tcs = new TaskCompletionSource<bool>();
        Task.Run(async delegate

AArnott

$AndroidToolPath = "${env:ProgramFiles(x86)}\Android\android-sdk\tools\android.bat"
if (!(Test-Path $AndroidToolPath)) {
  $AndroidToolPath = "$env:localappdata\Android\android-sdk\tools\android.bat"
} elseif (!(Test-Path $AndroidToolPath)) {
  Write-Error "Unable to find Android SDK Manager tools."
  return
}

Function Get-AndroidSDKs() {
    $output = & $AndroidToolPath list sdk --all