dotnet-channels

Name: dotnet-channels
Author: wshaddix

65stars10forks

How to install dotnet-channels?

wshaddix/dotnet-skills/dotnet-channels

$npx -y skills add wshaddix/dotnet-skills --skill dotnet-channels

Installs into the current project.

Summary

Using producer/consumer queues. Channel<T>, bounded/unbounded, backpressure, drain patterns

Files · 1

View on GitHub

SKILL.md

1	# dotnet-channels
2
3	Deep guide to `System.Threading.Channels` for high-performance, thread-safe producer/consumer communication in .NET. Covers channel creation, backpressure strategies, IAsyncEnumerable integration, and graceful shutdown patterns.
4
5	Out of scope: Hosted service lifecycle and `BackgroundService` registration are owned by [skill:dotnet-background-services]. Async/await fundamentals and cancellation token propagation are owned by [skill:dotnet-csharp-async-patterns].
6
7	Cross-references: [skill:dotnet-background-services] for integrating channels with hosted services, [skill:dotnet-csharp-async-patterns] for async patterns used in channel consumers.
8
9	---
10
11	## Channel<T> Fundamentals
12
13	A `Channel<T>` is a thread-safe data structure with separate `ChannelWriter<T>` and `ChannelReader<T>` endpoints. Writers produce items, readers consume them -- the channel handles all synchronization.
14
15	```csharp
16	// Create a channel and separate the endpoints
17	Channel<WorkItem> channel = Channel.CreateUnbounded<WorkItem>();
18	ChannelWriter<WorkItem> writer = channel.Writer;
19	ChannelReader<WorkItem> reader = channel.Reader;
20	```
21
22	### Bounded vs Unbounded
23
24	\| Aspect \| Bounded \| Unbounded \|
25	\|--------\|---------\|-----------\|
26	\| Creation \| `Channel.CreateBounded<T>(capacity)` \| `Channel.CreateUnbounded<T>()` \|
27	\| Back-pressure \| Yes -- `FullMode` controls behavior when full \| No -- grows without limit \|
28	\| Memory safety \| Capped at `capacity` items \| Can exhaust memory under load \|
29	\| Use when \| Production workloads, untrusted producer rates \| Guaranteed-low-volume, prototyping \|
30
31	```csharp
32	// Bounded -- preferred for production
33	var bounded = Channel.CreateBounded<WorkItem>(new BoundedChannelOptions(capacity: 1000)
34	{
35	FullMode = BoundedChannelFullMode.Wait
36	});
37
38	// Unbounded -- use only when you control the producer rate
39	var unbounded = Channel.CreateUnbounded<WorkItem>();
40	```
41
42	---
43
44	## BoundedChannelFullMode
45
46	Controls what happens when a bounded channel is full and a producer attempts to write.
47
48	\| Mode \| Behavior \| Use case \|
49	\|------\|----------\|----------\|
50	\| `Wait` \| `WriteAsync` blocks until space is available \| Default. Reliable delivery with back-pressure \|
51	\| `DropOldest` \| Drops the oldest item in the channel to make room \| Telemetry, metrics -- latest data matters most \|
52	\| `DropNewest` \| Drops the item being written (newest) \| Rate limiting -- discard excess incoming work \|
53	\| `DropWrite` \| Drops the item being written and returns `false` from `TryWrite` \| Non-blocking fire-and-forget with overflow detection \|
54
55	```csharp
56	// DropOldest -- telemetry pipeline where stale readings are expendable
57	var telemetryChannel = Channel.CreateBounded<SensorReading>(new BoundedChannelOptions(500)
58	{
59	FullMode = BoundedChannelFullMode.DropOldest
60	});
61
62	// DropWrite -- non-blocking enqueue with overflow awareness
63	var logChannel = Channel.CreateBounded<LogEntry>(new BoundedChannelOptions(10_000)
64	{
65	FullMode = BoundedChannelFullMode.DropWrite
66	});
67
68	if (!logChannel.Writer.TryWrite(entry))
69	{
70	// Channel full -- item was dropped; track overflow metric
71	overflowCounter.Add(1);
72	}
73	```
74
75	### itemDropped Callback (.NET 7+)
76
77	Starting in .NET 7, bounded channels with drop modes accept an `itemDropped` callback that fires whenever an item is discarded. Use this for metrics, logging, or resource cleanup on dropped items.
78
79	```csharp
80	var channel = Channel.CreateBounded(new BoundedChannelOptions(100)
81	{
82	FullMode = BoundedChannelFullMode.DropOldest
83	},
84	itemDropped: (item, writer) =>
85	{
86	logger.LogWarning("Dropped item due to channel overflow: {Id}", item.Id);
87	droppedItemsCounter.Add(1);
88	// Clean up disposable items if needed
89	(item as IDisposable)?.Dispose();
90	});
91	```
92
93	The callback receives the dropped item and the `ChannelWriter<T>` (useful if you need to re-route items to a fallback channel).
94
95	---
96
97	## Producer Patterns
98
99	### Single Producer
100
101	```csharp
102	// Write with back-pressure (bounded channels)
103	await writer.WriteAsync(item, cancellationToken);
104
105	// Non-blocking write attempt (returns false if channel is full or completed)
106	if (!writer.TryWrite(item))
107	{
108	// Handle overflow -- log, retry, or discard
109	}
110	```
111
112	### Multiple Producers
113
114	Multiple producers can call `WriteAsync` or `TryWrite` concurrently without external locking. The channel is internally thread-safe.
115
116	```csharp
117	// Multiple API endpoints enqueueing work into a shared channel
118	app.MapPost("/api/orders/{id}/process", async (
119	string id,
120	ChannelWriter<OrderCommand> writer,
121	CancellationToken ct) =>
122	{
123	await writer.WriteAsync(new OrderCommand(id, "process"), ct);
124	return Results.Accepted();
125	});
126
127	app.MapPost("/api/orders/{id}/cancel", async (
128	string id,
129	ChannelWriter<OrderCommand> writer,
130	CancellationToken ct) =>
131	{
132	await writer.WriteAsync(new OrderCommand(id, "cancel"), ct);
133	return Results.Accepted();
134	});
135	```
136
137	#

wshaddixPublisher · 77 listings

Preview

wshaddix/dotnet-skills

# dotnet-channels

Deep guide to `System.Threading.Channels` for high-performance, thread-safe producer/consumer communication in .NET. Covers channel creation, backpressure strat

**Out of scope:** Hosted service lifecycle and `BackgroundService` registration are owned by [skill:dotnet-background-services]. Async/await fundamentals and ca

Cross-references: [skill:dotnet-background-services] for integrating channels with hosted services, [skill:dotnet-csharp-async-patterns] for async patterns used

Repowshaddix/dotnet-skills

License—

TypeSkills

CategoryCoding

UpdatedFeb 2026

Repo stars65

First seenJul 22, 2026

People who liked this also viewed

6 picks

Type

dotnet-channels

65stars10forks

View on GitHub

How to install dotnet-channels?

wshaddix/dotnet-skills/dotnet-channels

$npx -y skills add wshaddix/dotnet-skills --skill dotnet-channels

Installs into the current project.

Summary

Using producer/consumer queues. Channel<T>, bounded/unbounded, backpressure, drain patterns

Files · 1

View on GitHub

SKILL.md

1	# dotnet-channels
2
3	Deep guide to `System.Threading.Channels` for high-performance, thread-safe producer/consumer communication in .NET. Covers channel creation, backpressure strategies, IAsyncEnumerable integration, and graceful shutdown patterns.
4
5	Out of scope: Hosted service lifecycle and `BackgroundService` registration are owned by [skill:dotnet-background-services]. Async/await fundamentals and cancellation token propagation are owned by [skill:dotnet-csharp-async-patterns].
6
7	Cross-references: [skill:dotnet-background-services] for integrating channels with hosted services, [skill:dotnet-csharp-async-patterns] for async patterns used in channel consumers.
8
9	---
10
11	## Channel<T> Fundamentals
12
13	A `Channel<T>` is a thread-safe data structure with separate `ChannelWriter<T>` and `ChannelReader<T>` endpoints. Writers produce items, readers consume them -- the channel handles all synchronization.
14
15	```csharp
16	// Create a channel and separate the endpoints
17	Channel<WorkItem> channel = Channel.CreateUnbounded<WorkItem>();
18	ChannelWriter<WorkItem> writer = channel.Writer;
19	ChannelReader<WorkItem> reader = channel.Reader;
20	```
21
22	### Bounded vs Unbounded
23
24	\| Aspect \| Bounded \| Unbounded \|
25	\|--------\|---------\|-----------\|
26	\| Creation \| `Channel.CreateBounded<T>(capacity)` \| `Channel.CreateUnbounded<T>()` \|
27	\| Back-pressure \| Yes -- `FullMode` controls behavior when full \| No -- grows without limit \|
28	\| Memory safety \| Capped at `capacity` items \| Can exhaust memory under load \|
29	\| Use when \| Production workloads, untrusted producer rates \| Guaranteed-low-volume, prototyping \|
30
31	```csharp
32	// Bounded -- preferred for production
33	var bounded = Channel.CreateBounded<WorkItem>(new BoundedChannelOptions(capacity: 1000)
34	{
35	FullMode = BoundedChannelFullMode.Wait
36	});
37
38	// Unbounded -- use only when you control the producer rate
39	var unbounded = Channel.CreateUnbounded<WorkItem>();
40	```
41
42	---
43
44	## BoundedChannelFullMode
45
46	Controls what happens when a bounded channel is full and a producer attempts to write.
47
48	\| Mode \| Behavior \| Use case \|
49	\|------\|----------\|----------\|
50	\| `Wait` \| `WriteAsync` blocks until space is available \| Default. Reliable delivery with back-pressure \|
51	\| `DropOldest` \| Drops the oldest item in the channel to make room \| Telemetry, metrics -- latest data matters most \|
52	\| `DropNewest` \| Drops the item being written (newest) \| Rate limiting -- discard excess incoming work \|
53	\| `DropWrite` \| Drops the item being written and returns `false` from `TryWrite` \| Non-blocking fire-and-forget with overflow detection \|
54
55	```csharp
56	// DropOldest -- telemetry pipeline where stale readings are expendable
57	var telemetryChannel = Channel.CreateBounded<SensorReading>(new BoundedChannelOptions(500)
58	{
59	FullMode = BoundedChannelFullMode.DropOldest
60	});
61
62	// DropWrite -- non-blocking enqueue with overflow awareness
63	var logChannel = Channel.CreateBounded<LogEntry>(new BoundedChannelOptions(10_000)
64	{
65	FullMode = BoundedChannelFullMode.DropWrite
66	});
67
68	if (!logChannel.Writer.TryWrite(entry))
69	{
70	// Channel full -- item was dropped; track overflow metric
71	overflowCounter.Add(1);
72	}
73	```
74
75	### itemDropped Callback (.NET 7+)
76
77	Starting in .NET 7, bounded channels with drop modes accept an `itemDropped` callback that fires whenever an item is discarded. Use this for metrics, logging, or resource cleanup on dropped items.
78
79	```csharp
80	var channel = Channel.CreateBounded(new BoundedChannelOptions(100)
81	{
82	FullMode = BoundedChannelFullMode.DropOldest
83	},
84	itemDropped: (item, writer) =>
85	{
86	logger.LogWarning("Dropped item due to channel overflow: {Id}", item.Id);
87	droppedItemsCounter.Add(1);
88	// Clean up disposable items if needed
89	(item as IDisposable)?.Dispose();
90	});
91	```
92
93	The callback receives the dropped item and the `ChannelWriter<T>` (useful if you need to re-route items to a fallback channel).
94
95	---
96
97	## Producer Patterns
98
99	### Single Producer
100
101	```csharp
102	// Write with back-pressure (bounded channels)
103	await writer.WriteAsync(item, cancellationToken);
104
105	// Non-blocking write attempt (returns false if channel is full or completed)
106	if (!writer.TryWrite(item))
107	{
108	// Handle overflow -- log, retry, or discard
109	}
110	```
111
112	### Multiple Producers
113
114	Multiple producers can call `WriteAsync` or `TryWrite` concurrently without external locking. The channel is internally thread-safe.
115
116	```csharp
117	// Multiple API endpoints enqueueing work into a shared channel
118	app.MapPost("/api/orders/{id}/process", async (
119	string id,
120	ChannelWriter<OrderCommand> writer,
121	CancellationToken ct) =>
122	{
123	await writer.WriteAsync(new OrderCommand(id, "process"), ct);
124	return Results.Accepted();
125	});
126
127	app.MapPost("/api/orders/{id}/cancel", async (
128	string id,
129	ChannelWriter<OrderCommand> writer,
130	CancellationToken ct) =>
131	{
132	await writer.WriteAsync(new OrderCommand(id, "cancel"), ct);
133	return Results.Accepted();
134	});
135	```
136
137	#

wshaddixPublisher · 77 listings

Preview

wshaddix/dotnet-skills

# dotnet-channels

Deep guide to `System.Threading.Channels` for high-performance, thread-safe producer/consumer communication in .NET. Covers channel creation, backpressure strat

**Out of scope:** Hosted service lifecycle and `BackgroundService` registration are owned by [skill:dotnet-background-services]. Async/await fundamentals and ca

Cross-references: [skill:dotnet-background-services] for integrating channels with hosted services, [skill:dotnet-csharp-async-patterns] for async patterns used

Repowshaddix/dotnet-skills

License—

TypeSkills

CategoryCoding

UpdatedFeb 2026

Repo stars65

First seenJul 22, 2026

People who liked this also viewed

6 picks

Type