Jump Golang Channels

Implementing scheduling feature for Golang channels in order to jump over low priority tasks in them. The reason for this feature is to send important data sooner. For scheduling buffered and unbuffered channels we used pyramid which is a heap data structure in Golang.

• Interface
  • create
  • schedule
• Example
• Benchmark

Interface

Just like Golang channels, we created an interface in order to simulate the channel behaviour. The interface goes like this:

type Channel interface {
    Send(interface{})
    Recv() (interface{}, bool)
    Close()
    Next() bool
}

create channel

In order to create channel, you can set size for it. If the size is zero then it would create an unbuffered channel. Otherwise it would create a buffered channel.

// buffered channel
ch := internal.NewChannel(2, false)

// unbuffered channel
uch := internal.NewChannel(0, false)

scheduling

To make a scheduled channel you need to create a channel with true input in second argument.

// buffered channel
ch := internal.NewChannel(10, true)

Make sure that your input data follows the following interface to have a priority method:

type (
	// Schedulable object has a priority method which
	// return the priority of that object for scheduling.
	Schedulable interface {
		Priority() int
	}
)

This method is used to sort channel data based on the priority.

Example

As you can see, I created a buffered channel with capacity of 2. Then we send data with order of low priority to high. But in consuming, it will get the high priority first and low priority later.

// buffered channel
ch := internal.NewChannel(2, true)
wg := sync.WaitGroup{}

wg.Add(2)

ch.Send(Data{
    Value: "low value",
    p:     1,
})
ch.Send(Data{
    Value: "high value",
    p:     2,
})

// create a go routine
go func() {
    for ch.Next() {
        msg, _ := ch.Recv()

        log.Println(msg.(Data).Value)

        wg.Done()
    }
}()

wg.Wait()
ch.Close()

output

2023/07/16 09:47:02 high value
2023/07/16 09:47:02 low value

diagram

Benchmark

In order to execute benchmarks, use make bench command.

BenchmarkChannel-8       8279013               121.0 ns/op
BenchmarkChannel-8      10276252               115.6 ns/op
BenchmarkChannel-8      10379642               115.7 ns/op
BenchmarkChannel-8      10325314               116.1 ns/op
BenchmarkChannel-8      10378026               115.6 ns/op
BenchmarkCJump-8           10000            249082 ns/op
BenchmarkCJump-8            5962            258694 ns/op
BenchmarkCJump-8           10000            262096 ns/op
BenchmarkCJump-8           10000            353728 ns/op
BenchmarkCJump-8            3676            288530 ns/op
PASS
ok      github.com/research-camp/go-channels-scheduling/test    6.967s