From 3766731de55556b25314d324ea8a53476f227edc Mon Sep 17 00:00:00 2001
From: Tyler Goodlet <jgbt@protonmail.com>
Date: Sat, 27 Feb 2021 14:21:27 -0500
Subject: [PATCH] Add a single func ex for our first one

---
 docs/README.rst                     | 59 +++++++++++++++++++++++++++++
 examples/parallelism/single_func.py | 43 +++++++++++++++++++++
 setup.py                            |  2 +-
 3 files changed, 103 insertions(+), 1 deletion(-)
 create mode 100644 examples/parallelism/single_func.py

diff --git a/docs/README.rst b/docs/README.rst
index ed19b83..2a5e42b 100644
--- a/docs/README.rst
+++ b/docs/README.rst
@@ -31,6 +31,64 @@ Features
   communications protocols, and environment specific IPC primitives
 
 
+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.
@@ -228,6 +286,7 @@ channel`_!
 .. _3 axioms: https://en.wikipedia.org/wiki/Actor_model#Fundamental_concepts
 .. _unrequirements: https://en.wikipedia.org/wiki/Actor_model#Direct_communication_and_asynchrony
 .. _async generators: https://www.python.org/dev/peps/pep-0525/
+.. _trio-parallel: https://github.com/richardsheridan/trio-parallel
 
 
 .. |gh_actions| image:: https://img.shields.io/endpoint.svg?url=https%3A%2F%2Factions-badge.atrox.dev%2Fgoodboy%2Ftractor%2Fbadge&style=popout-square
diff --git a/examples/parallelism/single_func.py b/examples/parallelism/single_func.py
new file mode 100644
index 0000000..8118b02
--- /dev/null
+++ b/examples/parallelism/single_func.py
@@ -0,0 +1,43 @@
+"""
+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)
diff --git a/setup.py b/setup.py
index cf3e838..4ed3b5f 100755
--- a/setup.py
+++ b/setup.py
@@ -24,7 +24,7 @@ with open('docs/README.rst', encoding='utf-8') as f:
 
 setup(
     name="tractor",
-    version='0.1.0a0.dev0',  # first ever alpha, dev release
+    version='0.1.0a0',  # first ever alpha
     description='structured concurrrent "actors"',
     long_description=readme,
     license='GPLv3',