docs/README.rst

@@ -1,4 +1,4 @@
-|logo| ``tractor``: distributed structured concurrency
+|logo| ``tractor``: distributed structurred concurrency
 
 ``tractor`` is a `structured concurrency`_ (SC), multi-processing_ runtime built on trio_.
 
@@ -57,7 +57,6 @@ Features
   `discovery`_ sys with plans to support multiple `modern protocol`_
   approaches.
 - Various ``trio`` extension APIs via ``tractor.trionics`` such as,
-
   - task fan-out `broadcasting`_,
   - multi-task-single-resource-caching and fan-out-to-multi
     ``__aenter__()`` APIs for ``@acm`` functions,
@@ -99,7 +98,7 @@ the code base::
 
     # but @goodboy prefers the more explicit (and shell agnostic)
     # https://docs.astral.sh/uv/configuration/environment/#uv_project_environment
-    UV_PROJECT_ENVIRONMENT="tractor_py313"
+    UV_PROJECT_ENVIRONMENT="tractor_py313
 
     # hint hint, enter @goodboy's fave shell B)
     uv run --dev xonsh
@@ -119,24 +118,84 @@ and rendered as the "Building these docs" section of our dev-tips guide.
 
 Example codez
 -------------
-We prefer to point you at the runnable scripts under ``examples/``
+In ``tractor``'s (very lacking) documention we prefer to point to
-- each is CI-run and ``literalinclude``-d straight into the docs, so
+example scripts in the repo over duplicating them in docs, but with
-what you read there is what actually runs - rather than duplicate a
+that in mind here are some definitive snippets to try and hook you
-pile of them here. But here's the one-minute pitch: spawn a subactor
+into digging deeper.
-per core, open a ``Context`` into each, then crash the root *on
+
-purpose* and watch the runtime reap the whole tree - zero zombies,
+
-guaranteed.
+Run a func in a process
+***********************
+Use ``trio``'s style of focussing on *tasks as functions*:
 
 .. code:: python
 
-    '''
+    """
+    Run with a process monitor from a terminal using::
+
+        $TERM -e watch -n 0.1  "pstree -a $$" \
+            & python examples/parallelism/single_func.py \
+            && kill $!
+
+    """
+    import os
+
+    import tractor
+    import trio
+
+
+    async def burn_cpu():
+
+        pid = os.getpid()
+
+        # burn a core @ ~ 50kHz
+        for _ in range(50000):
+            await trio.sleep(1/50000/50)
+
+        return os.getpid()
+
+
+    async def main():
+
+        async with tractor.open_nursery() as n:
+
+            portal = await n.run_in_actor(burn_cpu)
+
+            #  burn rubber in the parent too
+            await burn_cpu()
+
+            # wait on result from target function
+            pid = await portal.result()
+
+        # end of nursery block
+        print(f"Collected subproc {pid}")
+
+
+    if __name__ == '__main__':
+        trio.run(main)
+
+
+This runs ``burn_cpu()`` in a new process and reaps it on completion
+of the nursery block.
+
+If you only need to run a sync function and retreive a single result, you
+might want to check out `trio-parallel`_.
+
+
+Zombie safe: self-destruct a process tree
+*****************************************
+``tractor`` tries to protect you from zombies, no matter what.
+
+.. code:: python
+
+    """
     Run with a process monitor from a terminal using::
 
         $TERM -e watch -n 0.1  "pstree -a $$" \
             & python examples/parallelism/we_are_processes.py \
             && kill $!
 
-    '''
+    """
     from multiprocessing import cpu_count
     import os
 
@@ -144,70 +203,27 @@ guaranteed.
     import trio
 
 
-    @tractor.context
+    async def target():
-    async def endpoint(
+        print(
-        ctx: tractor.Context,
+            f"Yo, i'm '{tractor.current_actor().name}' "
-    ):
+            f"running in pid {os.getpid()}"
-        actor_name: str = tractor.current_actor().name
+        )
-        pid: int = os.getpid()
+
-        await ctx.started((actor_name, pid))
         await trio.sleep_forever()
 
 
-    async def spawn_and_open_ep(
-        an: tractor.ActorNursery,
-        i: int,
-    ) -> None:
-        '''
-        Spawn a subactor, start a remote `endpoint()`-task in it.
-
-        '''
-        ptl: tractor.Portal = await an.start_actor(
-            name=f'worker_{i}',
-            enable_modules=[__name__],
-        )
-        ctx: tractor.Context
-        async with ptl.open_context(endpoint) as (
-            ctx,
-            (sub_name, sub_pid),
-        ):
-            print(
-                f'Started ep-task in subactor,\n'
-                f'{i}::{sub_name!r}@{sub_pid}\n'
-            )
-            await ctx.wait_for_result()
-
-
     async def main():
-        '''
-        Spawn a subactor-per-CPU then self-destruct the cluster.
 
-        '''
+        async with tractor.open_nursery() as n:
-        tn: trio.Nursery
+
-        an: tractor.ActorNursery
-        async with (
-            tractor.open_nursery(
-                # XXX coming soon!
-                # https://github.com/goodboy/tractor/pull/463
-                # start_method='main_thread_forkserver',
-            ) as an,
-            # spawn subs concurrently (in bg `trio.Task`s) so each
-            # actor's cold `import tractor` (~0.4s, see #470) overlaps
-            # instead of stacking; once forkserver (#463) lands, spawn
-            # is cheap enough to just loop sequentially.
-            trio.open_nursery() as tn,
-        ):
             for i in range(cpu_count()):
-                tn.start_soon(
+                await n.run_in_actor(target, name=f'worker_{i}')
-                    spawn_and_open_ep,
+
-                    an,
+            print('This process tree will self-destruct in 1 sec...')
-                    i,
+            await trio.sleep(1)
-                )
+
-            destruct_in: int = 2
+            # raise an error in root actor/process and trigger
-            print(
+            # reaping of all minions
-                f'This tree will self-destruct in {destruct_in}s..\n'
-            )
-            await trio.sleep(destruct_in)
             raise Exception('Self Destructed')
 
 
@@ -218,16 +234,343 @@ guaranteed.
             print('Zombies Contained')
 
 
-If you can create zombie child processes (without using a system
+If you can create zombie child processes (without using a system signal)
-signal) it **is a bug** - please report it!
+it **is a bug**.
 
-Want more? Our docs walk the flagship multi-process debugger,
-bidirectional streaming over a ``Context``, cancellation, discovery,
-"infected ``asyncio``", typed messaging and worker-pool / cluster
-patterns - each backed by a runnable script:
 
-- docs: https://goodboy.github.io/tractor/
+"Native" multi-process debugging
-- examples: https://github.com/goodboy/tractor/tree/main/examples
+********************************
+Using the magic of `pdbp`_ and our internal IPC, we've
+been able to create a native feeling debugging experience for
+any (sub-)process in your ``tractor`` tree.
+
+.. code:: python
+
+    from os import getpid
+
+    import tractor
+    import trio
+
+
+    async def breakpoint_forever():
+        "Indefinitely re-enter debugger in child actor."
+        while True:
+            yield 'yo'
+            await tractor.breakpoint()
+
+
+    async def name_error():
+        "Raise a ``NameError``"
+        getattr(doggypants)
+
+
+    async def main():
+        """Test breakpoint in a streaming actor.
+        """
+        async with tractor.open_nursery(
+            debug_mode=True,
+            loglevel='error',
+        ) as n:
+
+            p0 = await n.start_actor('bp_forever', enable_modules=[__name__])
+            p1 = await n.start_actor('name_error', enable_modules=[__name__])
+
+            # retreive results
+            stream = await p0.run(breakpoint_forever)
+            await p1.run(name_error)
+
+
+    if __name__ == '__main__':
+        trio.run(main)
+
+
+You can run this with::
+
+    >>> python examples/debugging/multi_daemon_subactors.py
+
+And, yes, there's a built-in crash handling mode B)
+
+We're hoping to add a respawn-from-repl system soon!
+
+
+SC compatible bi-directional streaming
+**************************************
+Yes, you saw it here first; we provide 2-way streams
+with reliable, transitive setup/teardown semantics.
+
+Our nascent api is remniscent of ``trio.Nursery.start()``
+style invocation:
+
+.. code:: python
+
+    import trio
+    import tractor
+
+
+    @tractor.context
+    async def simple_rpc(
+
+        ctx: tractor.Context,
+        data: int,
+
+    ) -> None:
+        '''Test a small ping-pong 2-way streaming server.
+
+        '''
+        # signal to parent that we're up much like
+        # ``trio_typing.TaskStatus.started()``
+        await ctx.started(data + 1)
+
+        async with ctx.open_stream() as stream:
+
+            count = 0
+            async for msg in stream:
+
+                assert msg == 'ping'
+                await stream.send('pong')
+                count += 1
+
+            else:
+                assert count == 10
+
+
+    async def main() -> None:
+
+        async with tractor.open_nursery() as n:
+
+            portal = await n.start_actor(
+                'rpc_server',
+                enable_modules=[__name__],
+            )
+
+            # XXX: this syntax requires py3.9
+            async with (
+
+                portal.open_context(
+                    simple_rpc,
+                    data=10,
+                ) as (ctx, sent),
+
+                ctx.open_stream() as stream,
+            ):
+
+                assert sent == 11
+
+                count = 0
+                # receive msgs using async for style
+                await stream.send('ping')
+
+                async for msg in stream:
+                    assert msg == 'pong'
+                    await stream.send('ping')
+                    count += 1
+
+                    if count >= 9:
+                        break
+
+
+            # explicitly teardown the daemon-actor
+            await portal.cancel_actor()
+
+
+    if __name__ == '__main__':
+        trio.run(main)
+
+
+See original proposal and discussion in `#53`_ as well
+as follow up improvements in `#223`_ that we'd love to
+hear your thoughts on!
+
+.. _#53: https://github.com/goodboy/tractor/issues/53
+.. _#223: https://github.com/goodboy/tractor/issues/223
+
+
+Worker poolz are easy peasy
+***************************
+The initial ask from most new users is *"how do I make a worker
+pool thing?"*.
+
+``tractor`` is built to handle any SC (structured concurrent) process
+tree you can imagine; a "worker pool" pattern is a trivial special
+case.
+
+We have a `full worker pool re-implementation`_ of the std-lib's
+``concurrent.futures.ProcessPoolExecutor`` example for reference.
+
+You can run it like so (from this dir) to see the process tree in
+real time::
+
+    $TERM -e watch -n 0.1  "pstree -a $$" \
+        & python examples/parallelism/concurrent_actors_primes.py \
+        && kill $!
+
+This uses no extra threads, fancy semaphores or futures; all we need
+is ``tractor``'s IPC!
+
+"Infected ``asyncio``" mode
+***************************
+Have a bunch of ``asyncio`` code you want to force to be SC at the process level?
+
+Check out our experimental system for `guest`_-mode controlled
+``asyncio`` actors:
+
+.. code:: python
+
+    import asyncio
+    from statistics import mean
+    import time
+
+    import trio
+    import tractor
+
+
+    async def aio_echo_server(
+        chan: tractor.to_asyncio.LinkedTaskChannel,
+    ) -> None:
+
+        # a first message must be sent **from** this ``asyncio``
+        # task or the ``trio`` side will never unblock from
+        # ``tractor.to_asyncio.open_channel_from():``
+        chan.started_nowait('start')
+
+        while True:
+            # echo the msg back
+            chan.send_nowait(await chan.get())
+            await asyncio.sleep(0)
+
+
+    @tractor.context
+    async def trio_to_aio_echo_server(
+        ctx: tractor.Context,
+    ):
+        # this will block until the ``asyncio`` task sends a "first"
+        # message.
+        async with tractor.to_asyncio.open_channel_from(
+            aio_echo_server,
+        ) as (chan, first):
+
+            assert first == 'start'
+            await ctx.started(first)
+
+            async with ctx.open_stream() as stream:
+
+                async for msg in stream:
+                    await chan.send(msg)
+
+                    out = await chan.receive()
+                    # echo back to parent actor-task
+                    await stream.send(out)
+
+
+    async def main():
+
+        async with tractor.open_nursery() as n:
+            p = await n.start_actor(
+                'aio_server',
+                enable_modules=[__name__],
+                infect_asyncio=True,
+            )
+            async with p.open_context(
+                trio_to_aio_echo_server,
+            ) as (ctx, first):
+
+                assert first == 'start'
+
+                count = 0
+                async with ctx.open_stream() as stream:
+
+                    delays = []
+                    send = time.time()
+
+                    await stream.send(count)
+                    async for msg in stream:
+                        recv = time.time()
+                        delays.append(recv - send)
+                        assert msg == count
+                        count += 1
+                        send = time.time()
+                        await stream.send(count)
+
+                        if count >= 1e3:
+                            break
+
+            print(f'mean round trip rate (Hz): {1/mean(delays)}')
+            await p.cancel_actor()
+
+
+    if __name__ == '__main__':
+        trio.run(main)
+
+
+Yes, we spawn a python process, run ``asyncio``, start ``trio`` on the
+``asyncio`` loop, then send commands to the ``trio`` scheduled tasks to
+tell ``asyncio`` tasks what to do XD
+
+The ``asyncio``-side task receives a single
+``chan: LinkedTaskChannel`` handle providing a ``trio``-like
+API: ``.started_nowait()``, ``.send_nowait()``, ``.get()``
+and more. Feel free to sling your opinion in `#273`_!
+
+
+.. _#273: https://github.com/goodboy/tractor/issues/273
+
+
+Higher level "cluster" APIs
+***************************
+To be extra terse the ``tractor`` devs have started hacking some "higher
+level" APIs for managing actor trees/clusters. These interfaces should
+generally be condsidered provisional for now but we encourage you to try
+them and provide feedback. Here's a new API that let's you quickly
+spawn a flat cluster:
+
+.. code:: python
+
+    import trio
+    import tractor
+
+
+    async def sleepy_jane():
+        uid = tractor.current_actor().uid
+        print(f'Yo i am actor {uid}')
+        await trio.sleep_forever()
+
+
+    async def main():
+        '''
+        Spawn a flat actor cluster, with one process per
+        detected core.
+
+        '''
+        portal_map: dict[str, tractor.Portal]
+        results: dict[str, str]
+
+        # look at this hip new syntax!
+        async with (
+
+            tractor.open_actor_cluster(
+                modules=[__name__]
+            ) as portal_map,
+
+            trio.open_nursery() as n,
+        ):
+
+            for (name, portal) in portal_map.items():
+                n.start_soon(portal.run, sleepy_jane)
+
+            await trio.sleep(0.5)
+
+            # kill the cluster with a cancel
+            raise KeyboardInterrupt
+
+
+    if __name__ == '__main__':
+        try:
+            trio.run(main)
+        except KeyboardInterrupt:
+            pass
+
+
+.. _full worker pool re-implementation: https://github.com/goodboy/tractor/blob/master/examples/parallelism/concurrent_actors_primes.py
 
 
 Under the hood

docs/start/quickstart.rst

@@ -144,41 +144,26 @@ breakfast - run this while monitoring your process tree::
    ``_subactor[worker_0@<pid>]``, so ``pstree``/``htop``/
    ``pgrep -f`` can tell your actors apart at a glance.
 
-You'll see something like (one subactor per core - 24 on this box,
+You'll see something like::
-trimmed here)::
 
     $ python examples/parallelism/we_are_processes.py
-    This tree will self-destruct in 2s..
+    Yo, i'm 'worker_2' running in pid 1777246
-
+    Yo, i'm 'worker_0' running in pid 1777244
-    Started ep-task in subactor,
+    Yo, i'm 'worker_3' running in pid 1777247
-    0::'worker_0'@218140
+    Yo, i'm 'worker_1' running in pid 1777245
-
+    This process tree will self-destruct in 1 sec...
-    Started ep-task in subactor,
-    2::'worker_2'@218134
-
-    Started ep-task in subactor,
-    1::'worker_1'@218137
-
-    Started ep-task in subactor,
-    3::'worker_3'@218132
-
     Zombies Contained
 
-(The ``Started ep-task`` lines land in whatever order the OS
+(The worker lines land in whatever order the OS schedules them;
-schedules them; they're separate *processes*, racing, and that's
+they're separate *processes*, racing, and that's the point.)
-the point.)
 
-One subactor is spawned per core - concurrently, from background
+An actor is spawned per core, each parks itself in
-``trio`` tasks, so each child's cold ``import tractor`` overlaps
+``trio.sleep_forever()``... and then the root *crashes on
-instead of stacking. Each runs a ``@tractor.context``
+purpose*. The ``ActorNursery`` responds with hard ``trio``
-``endpoint()`` that ``ctx.started()``-hands its name and pid back
+discipline: every child is cancelled, every process is reaped,
-through ``Portal.open_context()`` (those ``Started ep-task``
+the error propagates to ``trio.run()``, and your terminal prints
-lines), then parks in ``trio.sleep_forever()``. Then the root
+``Zombies Contained``. No orphans, no ``kill -9`` archaeology in
-*crashes on purpose* and the ``ActorNursery`` responds with hard
+``htop`` afterwards.
-``trio`` discipline: every child is cancelled, every process is
-reaped, the error propagates to ``trio.run()``, and your terminal
-prints ``Zombies Contained``. No orphans, no ``kill -9``
-archaeology in ``htop`` afterwards.
 
 .. note::