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yield

yield()

Switch to the scheduler to allow another scheduled task to run. A task that calls this function is still runnable, and will be restarted immediately if there are no other runnable tasks.

Examples

In the Julia programming language, the function yield()

Switches to the scheduler to allow another scheduled task to run. A task that calls this function is still runnable and will be restarted immediately if there are no other runnable tasks.

julia> @async begin
           println("Task 1")
           yield()
           println("Task 1 resumed")
       end
       @async begin
           println("Task 2")
       end
Task 1
Task 2
Task 1 resumed

In this example, we have two tasks created using the @async macro. The first task prints "Task 1", then calls yield() to switch to the scheduler and allow the second task to run. After the second task completes, the first task is resumed and prints "Task 1 resumed".

Common examples of its use:

1. Allow other tasks to run in a long-running task:

   @async begin
      println("Task 1")
      # Perform some long-running task
      for i in 1:100000000
          # Do some computation
          if i % 10000000 == 0
              yield()
          end
      end
      println("Task 1 completed")
   end

   In this example, during a long-running task, yield() is called periodically to switch to the scheduler and allow other tasks to run. This helps prevent blocking other tasks and ensures fairness in task execution.

2. Cooperative multitasking between multiple tasks:

   @async begin
      for i in 1:5
          println("Task 1 - Step $i")
          yield()
      end
      println("Task 1 completed")
   end
   @async begin
      for i in 1:5
          println("Task 2 - Step $i")
          yield()
      end
      println("Task 2 completed")
   end

   This example demonstrates cooperative multitasking between two tasks. Each task performs a set of steps and then yields to allow the other task to run. This way, both tasks progress alternatively.

It's important to note that yield() has limited use outside of asynchronous tasks or when working with Julia's task scheduler. In general, it's not necessary to call yield() explicitly in regular Julia code.

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