Simple example

Overview¶

This example demonstrates different ways that the same code can be executed. This is an overview of the four cells shown in the animation below.

1. Define the coroutine function.
   1. Cell 'magic' %callers prints a list of Caller instances and the thread in which it is executing.
   2. A button is created and and it runs a loop twice:
      1. Creates any anyio event.
      2. Prints a statement.
      3. Waits for the button click to set the event.
2. Execute demo normally.
3. Execute demo concurrently in a task.
4. Execute demo in a thread.

In [1]:

import ipywidgets as ipw

from async_kernel import AsyncEvent, Caller, utils


async def demo():
    %callers
    caller = Caller()  # Use caller set the event in the waiting thread
    b = ipw.Button(description="Continue")
    display(b)
    for i in range(1, 3):
        b.description = f"Continue {i}"
        event = AsyncEvent()
        b.on_click(lambda _: caller.call_soon(event.set))  # noqa: B023
        print(f"Waiting {i}", end="\r")
        await event.wait()
    b.close()
    print("\nDone!")

import ipywidgets as ipw from async_kernel import AsyncEvent, Caller, utils async def demo(): %callers caller = Caller() # Use caller set the event in the waiting thread b = ipw.Button(description="Continue") display(b) for i in range(1, 3): b.description = f"Continue {i}" event = AsyncEvent() b.on_click(lambda _: caller.call_soon(event.set)) # noqa: B023 print(f"Waiting {i}", end="\r") await event.wait() b.close() print("\nDone!")

In [2]:

suppress-error

print(utils.get_tags())
await demo()

print(utils.get_tags()) await demo()

[]

Running	Protected			Name

──────────────────────────────────────────────────────────────────────

   ✓	   🔐		MainThread	← current thread

   ✓	   🔐		ControlThread	

Button(description='Continue', style=ButtonStyle())

Waiting 1

In [3]:

suppress-error

##task
await demo()

##task await demo()

Running	Protected			Name

──────────────────────────────────────────────────────────────────────

   ✓	   🔐		MainThread	← current thread

   ✓	   🔐		ControlThread	

Button(description='Continue', style=ButtonStyle())

Waiting 1

In [4]:

suppress-error

##thread
await demo()

##thread await demo()

Running	Protected			Name

──────────────────────────────────────────────────────────────────────

   ✓	   🔐		MainThread	

   ✓	   🔐		ControlThread	

   ✓			Thread-13 (async_kernel_caller)	

   ✓			Thread-15 (async_kernel_caller)	← current thread

Button(description='Continue', style=ButtonStyle())

Waiting 1

Caller.as_completed¶

See also: the caller notebook.

In [5]:

suppress-error

async for _ in Caller.as_completed(Caller().call_soon(demo) for _ in range(2)):
    pass

async for _ in Caller.as_completed(Caller().call_soon(demo) for _ in range(2)): pass

Running	Protected			Name

──────────────────────────────────────────────────────────────────────

   ✓	   🔐		MainThread	← current thread

   ✓	   🔐		ControlThread	

   ✓			Thread-13 (async_kernel_caller)	

   ✓			Thread-15 (async_kernel_caller)	

Button(description='Continue', style=ButtonStyle())

Waiting 1

Running	Protected			Name

──────────────────────────────────────────────────────────────────────

   ✓	   🔐		MainThread	← current thread

   ✓	   🔐		ControlThread	

   ✓			Thread-13 (async_kernel_caller)	

   ✓			Thread-15 (async_kernel_caller)	

Button(description='Continue', style=ButtonStyle())

Waiting 1