public override async Task DisposeAsyncReleasesQueuedAcquires()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 3,
TimeSpan.Zero, 1, autoReplenishment: false));
var lease = limiter.Acquire(1);
var wait1 = limiter.WaitAsync(1);
var wait2 = limiter.WaitAsync(1);
var wait3 = limiter.WaitAsync(1);
Assert.False(wait1.IsCompleted);
Assert.False(wait2.IsCompleted);
Assert.False(wait3.IsCompleted);
await limiter.DisposeAsync();
lease = await wait1;
Assert.False(lease.IsAcquired);
lease = await wait2;
Assert.False(lease.IsAcquired);
lease = await wait3;
Assert.False(lease.IsAcquired);
// Throws after disposal
Assert.Throws <ObjectDisposedException>(() => limiter.Acquire(1));
await Assert.ThrowsAsync <ObjectDisposedException>(() => limiter.WaitAsync(1).AsTask());
}
public override void AcquireZero_WithoutAvailability()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.NewestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
using var lease = limiter.Acquire(1);
Assert.True(lease.IsAcquired);
var lease2 = limiter.Acquire(0);
Assert.False(lease2.IsAcquired);
lease2.Dispose();
}
public override void CanAcquireResource()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.NewestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
var lease = limiter.Acquire();
Assert.True(lease.IsAcquired);
Assert.False(limiter.Acquire().IsAcquired);
lease.Dispose();
Assert.False(limiter.Acquire().IsAcquired);
Assert.True(limiter.TryReplenish());
Assert.True(limiter.Acquire().IsAcquired);
}
public void TryReplenishHonorsTokensPerPeriod()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(7, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.Zero, 3, autoReplenishment: false));
Assert.True(limiter.Acquire(5).IsAcquired);
Assert.False(limiter.Acquire(3).IsAcquired);
Assert.Equal(2, limiter.GetAvailablePermits());
Assert.True(limiter.TryReplenish());
Assert.Equal(5, limiter.GetAvailablePermits());
Assert.True(limiter.TryReplenish());
Assert.Equal(7, limiter.GetAvailablePermits());
}
public async Task ReplenishWorksWithTicksOverInt32Max()
{
using var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(10, QueueProcessingOrder.OldestFirst, 2,
TimeSpan.FromMilliseconds(2), 1, autoReplenishment: false));
var lease = limiter.Acquire(10);
Assert.True(lease.IsAcquired);
var wait = limiter.WaitAndAcquireAsync(1);
Assert.False(wait.IsCompleted);
var replenishInternalMethod = typeof(TokenBucketRateLimiter).GetMethod("ReplenishInternal", Reflection.BindingFlags.NonPublic | Reflection.BindingFlags.Instance) !;
// Ensure next tick is over uint.MaxValue
var tick = Stopwatch.GetTimestamp() + uint.MaxValue;
replenishInternalMethod.Invoke(limiter, new object[] { tick });
lease = await wait;
Assert.True(lease.IsAcquired);
wait = limiter.WaitAndAcquireAsync(1);
Assert.False(wait.IsCompleted);
// Tick 1 millisecond too soon and verify that the queued item wasn't completed
replenishInternalMethod.Invoke(limiter, new object[] { tick + 1L * (long)(TimeSpan.TicksPerMillisecond / TickFrequency) });
Assert.False(wait.IsCompleted);
// ticks would wrap if using uint
replenishInternalMethod.Invoke(limiter, new object[] { tick + 2L * (long)(TimeSpan.TicksPerMillisecond / TickFrequency) });
lease = await wait;
Assert.True(lease.IsAcquired);
}
public override async Task CanAcquireResourcesWithWaitAsyncWithQueuedItemsIfNewestFirst()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(2, QueueProcessingOrder.NewestFirst, 2,
TimeSpan.Zero, 2, autoReplenishment: false));
var lease = limiter.Acquire(1);
Assert.True(lease.IsAcquired);
var wait = limiter.WaitAsync(2);
Assert.False(wait.IsCompleted);
Assert.Equal(1, limiter.GetAvailablePermits());
lease = await limiter.WaitAsync(1).DefaultTimeout();
Assert.True(lease.IsAcquired);
Assert.False(wait.IsCompleted);
limiter.TryReplenish();
lease = await wait.DefaultTimeout();
Assert.True(lease.IsAcquired);
}
public override async Task CanFillQueueWithNewestFirstAfterCancelingQueuedRequestWithAnotherQueuedRequest()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(2, QueueProcessingOrder.NewestFirst, 2,
TimeSpan.Zero, 2, autoReplenishment: false));
var lease = limiter.Acquire(2);
Assert.True(lease.IsAcquired);
var cts = new CancellationTokenSource();
var wait = limiter.WaitAndAcquireAsync(1, cts.Token);
// Add another item to queue, will be completed as failed later when we queue another item
var wait2 = limiter.WaitAndAcquireAsync(1);
Assert.False(wait.IsCompleted);
cts.Cancel();
var ex = await Assert.ThrowsAsync <TaskCanceledException>(() => wait.AsTask());
Assert.Equal(cts.Token, ex.CancellationToken);
lease.Dispose();
var wait3 = limiter.WaitAndAcquireAsync(2);
Assert.False(wait3.IsCompleted);
// will be kicked by wait3 because we're using NewestFirst
lease = await wait2;
Assert.False(lease.IsAcquired);
limiter.TryReplenish();
lease = await wait3;
Assert.True(lease.IsAcquired);
}
public override async Task LargeAcquiresAndQueuesDoNotIntegerOverflow()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(int.MaxValue, QueueProcessingOrder.NewestFirst, int.MaxValue,
TimeSpan.Zero, int.MaxValue, autoReplenishment: false));
var lease = limiter.Acquire(int.MaxValue);
Assert.True(lease.IsAcquired);
// Fill queue
var wait = limiter.WaitAsync(3);
Assert.False(wait.IsCompleted);
var wait2 = limiter.WaitAsync(int.MaxValue);
Assert.False(wait2.IsCompleted);
var lease1 = await wait;
Assert.False(lease1.IsAcquired);
limiter.TryReplenish();
var lease2 = await wait2;
Assert.True(lease2.IsAcquired);
}
public override async Task CannotAcquireResourcesWithWaitAsyncWithQueuedItemsIfOldestFirst()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(2, QueueProcessingOrder.OldestFirst, 3,
TimeSpan.Zero, 2, autoReplenishment: false));
var lease = limiter.Acquire(1);
Assert.True(lease.IsAcquired);
var wait = limiter.WaitAsync(2);
var wait2 = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
Assert.False(wait2.IsCompleted);
limiter.TryReplenish();
lease = await wait;
Assert.True(lease.IsAcquired);
Assert.False(wait2.IsCompleted);
limiter.TryReplenish();
lease = await wait2;
Assert.True(lease.IsAcquired);
}
public override async Task DropsMultipleOldestWhenQueuingMoreThanLimit_NewestFirst()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(2, QueueProcessingOrder.NewestFirst, 2,
TimeSpan.Zero, 1, autoReplenishment: false));
var lease = limiter.Acquire(2);
Assert.True(lease.IsAcquired);
var wait = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
var wait2 = limiter.WaitAsync(1);
Assert.False(wait2.IsCompleted);
var wait3 = limiter.WaitAsync(2);
var lease1 = await wait;
var lease2 = await wait2;
Assert.False(lease1.IsAcquired);
Assert.False(lease2.IsAcquired);
Assert.False(wait3.IsCompleted);
limiter.TryReplenish();
limiter.TryReplenish();
lease = await wait3;
Assert.True(lease.IsAcquired);
}
public override void ThrowsWhenAcquiringLessThanZero()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.NewestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
Assert.Throws <ArgumentOutOfRangeException>(() => limiter.Acquire(-1));
}
public override void NullIdleDurationWhenActive()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 2,
TimeSpan.FromMilliseconds(2), 1, autoReplenishment: false));
limiter.Acquire(1);
Assert.Null(limiter.IdleDuration);
}
public override void MetadataNamesContainsAllMetadata()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
using var lease = limiter.Acquire(1);
Assert.Collection(lease.MetadataNames, metadataName => Assert.Equal(metadataName, MetadataName.RetryAfter.Name));
}
public override void NoMetadataOnAcquiredLease()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
using var lease = limiter.Acquire(1);
Assert.False(lease.TryGetMetadata(MetadataName.RetryAfter, out _));
}
public override void IdleDurationUpdatesWhenChangingFromActive()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 2,
TimeSpan.Zero, 1, autoReplenishment: false));
limiter.Acquire(1);
limiter.TryReplenish();
Assert.NotNull(limiter.IdleDuration);
}
public async Task AutoReplenish_ReplenishesTokens()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(2, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.FromMilliseconds(1000), 1, autoReplenishment: true));
Assert.Equal(2, limiter.GetAvailablePermits());
limiter.Acquire(2);
var lease = await limiter.WaitAsync(1);
Assert.True(lease.IsAcquired);
}
public override async Task FailsWhenQueuingMoreThanLimit_OldestFirst()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
using var lease = limiter.Acquire(1);
var wait = limiter.WaitAsync(1);
var failedLease = await limiter.WaitAsync(1);
Assert.False(failedLease.IsAcquired);
Assert.True(failedLease.TryGetMetadata(MetadataName.RetryAfter, out var timeSpan));
Assert.Equal(TimeSpan.Zero, timeSpan);
}
public async Task CorrectRetryMetadataWithNonZeroAvailableItems()
{
var options = new TokenBucketRateLimiterOptions(3, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.FromSeconds(20), 1, autoReplenishment: false);
var limiter = new TokenBucketRateLimiter(options);
using var lease = limiter.Acquire(2);
var failedLease = await limiter.WaitAsync(3);
Assert.False(failedLease.IsAcquired);
Assert.True(failedLease.TryGetMetadata(MetadataName.RetryAfter, out var typedMetadata));
Assert.Equal(options.ReplenishmentPeriod.Ticks * 2, typedMetadata.Ticks);
}
public async Task CorrectRetryMetadataWithLargeTokensPerPeriod()
{
var options = new TokenBucketRateLimiterOptions(2, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.FromSeconds(20), 100, autoReplenishment: false);
var limiter = new TokenBucketRateLimiter(options);
using var lease = limiter.Acquire(2);
// Queue item which changes the retry after time for failed items
var wait = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
var failedLease = await limiter.WaitAsync(2);
Assert.False(failedLease.IsAcquired);
Assert.True(failedLease.TryGetMetadata(MetadataName.RetryAfter, out var typedMetadata));
Assert.Equal(options.ReplenishmentPeriod, typedMetadata);
}
public async Task RetryMetadataOnFailedWaitAsync()
{
var options = new TokenBucketRateLimiterOptions(2, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.FromSeconds(20), 1, autoReplenishment: false);
var limiter = new TokenBucketRateLimiter(options);
using var lease = limiter.Acquire(2);
var failedLease = await limiter.WaitAsync(2).DefaultTimeout();
Assert.False(failedLease.IsAcquired);
Assert.True(failedLease.TryGetMetadata(MetadataName.RetryAfter.Name, out var metadata));
Assert.Equal(options.ReplenishmentPeriod * 2, metadata);
Assert.True(failedLease.TryGetMetadata(MetadataName.RetryAfter, out var typedMetadata));
Assert.Equal(options.ReplenishmentPeriod * 2, typedMetadata);
Assert.Collection(failedLease.MetadataNames, item => item.Equals(MetadataName.RetryAfter.Name));
}
public override async Task CanCancelWaitAsyncBeforeQueuing()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
var lease = limiter.Acquire(1);
Assert.True(lease.IsAcquired);
var cts = new CancellationTokenSource();
cts.Cancel();
await Assert.ThrowsAsync <TaskCanceledException>(() => limiter.WaitAsync(1, cts.Token).AsTask());
lease.Dispose();
Assert.True(limiter.TryReplenish());
Assert.Equal(1, limiter.GetAvailablePermits());
}
public override async Task CanDisposeAfterCancelingQueuedRequest()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
var lease = limiter.Acquire(1);
Assert.True(lease.IsAcquired);
var cts = new CancellationTokenSource();
var wait = limiter.WaitAndAcquireAsync(1, cts.Token);
cts.Cancel();
var ex = await Assert.ThrowsAsync <TaskCanceledException>(() => wait.AsTask());
Assert.Equal(cts.Token, ex.CancellationToken);
// Make sure dispose doesn't have any side-effects when dealing with a canceled queued item
limiter.Dispose();
}
public override async Task DropsRequestedLeaseIfPermitCountGreaterThanQueueLimitAndNoAvailability_NewestFirst()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(2, QueueProcessingOrder.NewestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
var lease = limiter.Acquire(2);
Assert.True(lease.IsAcquired);
// Fill queue
var wait = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
var lease1 = await limiter.WaitAsync(2);
Assert.False(lease1.IsAcquired);
limiter.TryReplenish();
lease = await wait;
Assert.True(lease.IsAcquired);
}
public async Task ReplenishWorksWhenTicksWrap()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(10, QueueProcessingOrder.OldestFirst, 2,
TimeSpan.FromMilliseconds(2), 1, autoReplenishment: false));
var lease = limiter.Acquire(10);
Assert.True(lease.IsAcquired);
var wait = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
// This will set the last tick to the max value
limiter.ReplenishInternal(uint.MaxValue);
lease = await wait.DefaultTimeout();
Assert.True(lease.IsAcquired);
wait = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
// ticks wrapped, should replenish
limiter.ReplenishInternal(2);
lease = await wait.DefaultTimeout();
Assert.True(lease.IsAcquired);
limiter.ReplenishInternal(uint.MaxValue);
wait = limiter.WaitAsync(2);
Assert.False(wait.IsCompleted);
// ticks wrapped, but only 1 millisecond passed, make sure the wrapping behaves correctly and replenish doesn't happen
limiter.ReplenishInternal(1);
Assert.False(wait.IsCompleted);
Assert.Equal(1, limiter.GetAvailablePermits());
}
public async Task ReplenishWorksWhenTicksWrap()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(10, QueueProcessingOrder.OldestFirst, 2,
TimeSpan.FromMilliseconds(2), 1, autoReplenishment: false));
var lease = limiter.Acquire(10);
Assert.True(lease.IsAcquired);
var wait = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
var replenishInternalMethod = typeof(TokenBucketRateLimiter).GetMethod("ReplenishInternal", Reflection.BindingFlags.NonPublic | Reflection.BindingFlags.Instance) !;
// This will set the last tick to the max value
replenishInternalMethod.Invoke(limiter, new object[] { uint.MaxValue });
lease = await wait;
Assert.True(lease.IsAcquired);
wait = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
// ticks wrapped, should replenish
replenishInternalMethod.Invoke(limiter, new object[] { 2U });
lease = await wait;
Assert.True(lease.IsAcquired);
replenishInternalMethod.Invoke(limiter, new object[] { uint.MaxValue });
wait = limiter.WaitAsync(2);
Assert.False(wait.IsCompleted);
// ticks wrapped, but only 1 millisecond passed, make sure the wrapping behaves correctly and replenish doesn't happen
replenishInternalMethod.Invoke(limiter, new object[] { 1U });
Assert.False(wait.IsCompleted);
Assert.Equal(1, limiter.GetAvailablePermits());
}
public override async Task QueueAvailableAfterQueueLimitHitAndResources_BecomeAvailable()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
var lease = limiter.Acquire(1);
var wait = limiter.WaitAsync(1);
var failedLease = await limiter.WaitAsync(1);
Assert.False(failedLease.IsAcquired);
limiter.TryReplenish();
lease = await wait;
Assert.True(lease.IsAcquired);
wait = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
limiter.TryReplenish();
lease = await wait;
Assert.True(lease.IsAcquired);
}
public override async Task CancelUpdatesQueueLimit()
{
var limiter = new TokenBucketRateLimiter(new TokenBucketRateLimiterOptions(1, QueueProcessingOrder.OldestFirst, 1,
TimeSpan.Zero, 1, autoReplenishment: false));
var lease = limiter.Acquire(1);
Assert.True(lease.IsAcquired);
var cts = new CancellationTokenSource();
var wait = limiter.WaitAsync(1, cts.Token);
cts.Cancel();
var ex = await Assert.ThrowsAsync <TaskCanceledException>(() => wait.AsTask());
Assert.Equal(cts.Token, ex.CancellationToken);
wait = limiter.WaitAsync(1);
Assert.False(wait.IsCompleted);
limiter.TryReplenish();
lease = await wait;
Assert.True(lease.IsAcquired);
}