Make ring buf api use pickle-able RBToken

tests/test_ringbuf.py

@@ -4,7 +4,8 @@ import trio
 import pytest
 import tractor
 from tractor.ipc import (
-    open_eventfd,
+    open_ringbuf,
+    RBToken,
     RingBuffSender,
     RingBuffReceiver
 )
@@ -15,22 +16,16 @@ from tractor._testing.samples import generate_sample_messages
 async def child_read_shm(
     ctx: tractor.Context,
     msg_amount: int,
-    shm_key: str,
+    token: RBToken,
-    write_eventfd: int,
-    wrap_eventfd: int,
     buf_size: int,
     total_bytes: int,
-    flags: int = 0,
 ) -> None:
     recvd_bytes = 0
     await ctx.started()
     start_ts = time.time()
     async with RingBuffReceiver(
-        shm_key,
+        token,
-        write_eventfd,
-        wrap_eventfd,
         buf_size=buf_size,
-        flags=flags
     ) as receiver:
         while recvd_bytes < total_bytes:
             msg = await receiver.receive_some()
@@ -55,9 +50,7 @@ async def child_write_shm(
     msg_amount: int,
     rand_min: int,
     rand_max: int,
-    shm_key: str,
+    token: RBToken,
-    write_eventfd: int,
-    wrap_eventfd: int,
     buf_size: int,
 ) -> None:
     msgs, total_bytes = generate_sample_messages(
@@ -67,9 +60,7 @@ async def child_write_shm(
     )
     await ctx.started(total_bytes)
     async with RingBuffSender(
-        shm_key,
+        token,
-        write_eventfd,
-        wrap_eventfd,
         buf_size=buf_size
     ) as sender:
         for msg in msgs:
@@ -100,52 +91,46 @@ def test_ringbuf(
     rand_max: int,
     buf_size: int
 ):
-    write_eventfd = open_eventfd()
-    wrap_eventfd = open_eventfd()
-
-    proc_kwargs = {
-        'pass_fds': (write_eventfd, wrap_eventfd)
-    }
-
-    shm_key = 'test_ring_buff'
-
-    common_kwargs = {
-        'msg_amount': msg_amount,
-        'shm_key': shm_key,
-        'write_eventfd': write_eventfd,
-        'wrap_eventfd': wrap_eventfd,
-        'buf_size': buf_size
-    }
-
     async def main():
-        async with tractor.open_nursery() as an:
-            send_p = await an.start_actor(
-                'ring_sender',
-                enable_modules=[__name__],
-                proc_kwargs=proc_kwargs
-            )
-            recv_p = await an.start_actor(
-                'ring_receiver',
-                enable_modules=[__name__],
-                proc_kwargs=proc_kwargs
-            )
-            async with (
-                send_p.open_context(
-                    child_write_shm,
-                    rand_min=rand_min,
-                    rand_max=rand_max,
-                    **common_kwargs
-                ) as (sctx, total_bytes),
-                recv_p.open_context(
-                    child_read_shm,
-                    **common_kwargs,
-                    total_bytes=total_bytes,
-                ) as (sctx, _sent),
-            ):
-                await recv_p.result()
 
-            await send_p.cancel_actor()
+        with open_ringbuf('test_ringbuf') as token:
-            await recv_p.cancel_actor()
+            proc_kwargs = {
+                'pass_fds': (token.write_eventfd, token.wrap_eventfd)
+            }
+
+            common_kwargs = {
+                'msg_amount': msg_amount,
+                'token': token,
+                'buf_size': buf_size
+            }
+            async with tractor.open_nursery() as an:
+                send_p = await an.start_actor(
+                    'ring_sender',
+                    enable_modules=[__name__],
+                    proc_kwargs=proc_kwargs
+                )
+                recv_p = await an.start_actor(
+                    'ring_receiver',
+                    enable_modules=[__name__],
+                    proc_kwargs=proc_kwargs
+                )
+                async with (
+                    send_p.open_context(
+                        child_write_shm,
+                        rand_min=rand_min,
+                        rand_max=rand_max,
+                        **common_kwargs
+                    ) as (sctx, total_bytes),
+                    recv_p.open_context(
+                        child_read_shm,
+                        **common_kwargs,
+                        total_bytes=total_bytes,
+                    ) as (sctx, _sent),
+                ):
+                    await recv_p.result()
+
+                await send_p.cancel_actor()
+                await recv_p.cancel_actor()
 
 
     trio.run(main)
@@ -154,55 +139,35 @@ def test_ringbuf(
 @tractor.context
 async def child_blocked_receiver(
     ctx: tractor.Context,
-    shm_key: str,
+    token: RBToken
-    write_eventfd: int,
-    wrap_eventfd: int,
-    flags: int = 0
 ):
-    async with RingBuffReceiver(
+    async with RingBuffReceiver(token) as receiver:
-        shm_key,
-        write_eventfd,
-        wrap_eventfd,
-        flags=flags
-    ) as receiver:
         await ctx.started()
         await receiver.receive_some()
 
 
 def test_ring_reader_cancel():
-    write_eventfd = open_eventfd()
-    wrap_eventfd = open_eventfd()
-
-    proc_kwargs = {
-        'pass_fds': (write_eventfd, wrap_eventfd)
-    }
-
-    shm_key = 'test_ring_cancel'
-
     async def main():
-        async with (
+        with open_ringbuf('test_ring_cancel') as token:
-            tractor.open_nursery() as an,
-            RingBuffSender(
-                shm_key,
-                write_eventfd,
-                wrap_eventfd,
-            ) as _sender,
-        ):
-            recv_p = await an.start_actor(
-                'ring_blocked_receiver',
-                enable_modules=[__name__],
-                proc_kwargs=proc_kwargs
-            )
             async with (
-                recv_p.open_context(
+                tractor.open_nursery() as an,
-                    child_blocked_receiver,
+                RingBuffSender(token) as _sender,
-                    write_eventfd=write_eventfd,
-                    wrap_eventfd=wrap_eventfd,
-                    shm_key=shm_key,
-                ) as (sctx, _sent),
             ):
-                await trio.sleep(1)
+                recv_p = await an.start_actor(
-                await an.cancel()
+                    'ring_blocked_receiver',
+                    enable_modules=[__name__],
+                    proc_kwargs={
+                        'pass_fds': (token.write_eventfd, token.wrap_eventfd)
+                    }
+                )
+                async with (
+                    recv_p.open_context(
+                        child_blocked_receiver,
+                        token=token
+                    ) as (sctx, _sent),
+                ):
+                    await trio.sleep(1)
+                    await an.cancel()
 
 
     with pytest.raises(tractor._exceptions.ContextCancelled):

tractor/ipc/__init__.py

@@ -36,6 +36,8 @@ if platform.system() == 'Linux':
     )
 
     from ._ringbuf import (
+        RBToken as RBToken,
         RingBuffSender as RingBuffSender,
-        RingBuffReceiver as RingBuffReceiver
+        RingBuffReceiver as RingBuffReceiver,
+        open_ringbuf
     )

tractor/ipc/_ringbuf.py

@@ -17,16 +17,58 @@
 IPC Reliable RingBuffer implementation
 
 '''
+from __future__ import annotations
+from contextlib import contextmanager as cm
 from multiprocessing.shared_memory import SharedMemory
 
 import trio
+from msgspec import (
+    Struct,
+    to_builtins
+)
 
 from ._linux import (
     EFD_NONBLOCK,
+    open_eventfd,
     EventFD
 )
 
 
+class RBToken(Struct, frozen=True):
+    '''
+    RingBuffer token contains necesary info to open the two
+    eventfds and the shared memory
+
+    '''
+    shm_name: str
+    write_eventfd: int
+    wrap_eventfd: int
+
+    def as_msg(self):
+        return to_builtins(self)
+
+    @classmethod
+    def from_msg(cls, msg: dict) -> RBToken:
+        if isinstance(msg, RBToken):
+            return msg
+
+        return RBToken(**msg)
+
+
+@cm
+def open_ringbuf(
+    shm_name: str,
+    write_efd_flags: int = 0,
+    wrap_efd_flags: int = 0
+) -> RBToken:
+    token = RBToken(
+        shm_name=shm_name,
+        write_eventfd=open_eventfd(flags=write_efd_flags),
+        wrap_eventfd=open_eventfd(flags=wrap_efd_flags)
+    )
+    yield token
+
+
 class RingBuffSender(trio.abc.SendStream):
     '''
     IPC Reliable Ring Buffer sender side implementation
@@ -34,26 +76,22 @@ class RingBuffSender(trio.abc.SendStream):
     `eventfd(2)` is used for wrap around sync, and also to signal
     writes to the reader.
 
-    TODO: if blocked on wrap around event wait it will not respond
-    to signals, fix soon TM
     '''
-
     def __init__(
         self,
-        shm_key: str,
+        token: RBToken,
-        write_eventfd: int,
-        wrap_eventfd: int,
         start_ptr: int = 0,
         buf_size: int = 10 * 1024,
-        unlink_on_exit: bool = True
+        unlink_on_exit: bool = False
     ):
+        token = RBToken.from_msg(token)
         self._shm = SharedMemory(
-            name=shm_key,
+            name=token.shm_name,
             size=buf_size,
             create=True
         )
-        self._write_event = EventFD(write_eventfd, 'w')
+        self._write_event = EventFD(token.write_eventfd, 'w')
-        self._wrap_event = EventFD(wrap_eventfd, 'r')
+        self._wrap_event = EventFD(token.wrap_eventfd, 'r')
         self._ptr = start_ptr
         self.unlink_on_exit = unlink_on_exit
 
@@ -123,29 +161,22 @@ class RingBuffReceiver(trio.abc.ReceiveStream):
     `eventfd(2)` is used for wrap around sync, and also to signal
     writes to the reader.
 
-    Unless eventfd(2) object is opened with EFD_NONBLOCK flag,
-    calls to `receive_some` will block the signal handling,
-    on the main thread, for now solution is using polling,
-    working on a way to unblock GIL during read(2) to allow
-    signal processing on the main thread.
     '''
-
     def __init__(
         self,
-        shm_key: str,
+        token: RBToken,
-        write_eventfd: int,
-        wrap_eventfd: int,
         start_ptr: int = 0,
         buf_size: int = 10 * 1024,
         flags: int = 0
     ):
+        token = RBToken.from_msg(token)
         self._shm = SharedMemory(
-            name=shm_key,
+            name=token.shm_name,
             size=buf_size,
             create=False
         )
-        self._write_event = EventFD(write_eventfd, 'w')
+        self._write_event = EventFD(token.write_eventfd, 'w')
-        self._wrap_event = EventFD(wrap_eventfd, 'r')
+        self._wrap_event = EventFD(token.wrap_eventfd, 'r')
         self._ptr = start_ptr
         self._flags = flags