Why Do Goroutines Block Each Other, and How Can This Be Addressed?

Goroutine Blocking Other Goroutines

In the given code snippet, the first goroutine enters an infinite loop, blocking the remaining goroutine from sending to the timeout channel. This behavior is a characteristic of cooperative scheduling in goroutines.

Goroutines yield to the scheduler in the following scenarios:

• Sending or receiving to/from unbuffered channels
• System calls (e.g., file reads or network writes)
• Memory allocation
• Calling time.Sleep()
• Calling runtime.Gosched()

In this case, the infinite loop in the first goroutine prevents it from yielding to the scheduler. Therefore, the other goroutine cannot send to the timeout channel, and the program continues to run indefinitely instead of terminating after one second.

One potential solution to this issue is to use a preemptive scheduler instead of a cooperative scheduler. In a preemptive scheduler, the system forcibly switches between goroutines based on their priorities. However, Go currently uses a cooperative scheduler.

Another strategy is to manually yield to the scheduler using runtime.Gosched(). However, this technique is generally not necessary in most programs due to sufficient communication via channels or system I/O.

It's important to note that setting GOMAXPROCS to a higher value may not completely resolve the issue. While it allows multiple goroutines to run in parallel, the garbage collector still operates in a synchronous manner. If the high CPU goroutines never yield, the GC can indefinitely block other goroutines while running.

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