Merge pull request #220 from goodboy/ctx_debugger

Ctx debugger

examples/debugging/fast_error_in_root_after_spawn.py

@@ -0,0 +1,54 @@
+'''
+Fast fail test with a context.
+
+Ensure the partially initialized sub-actor process
+doesn't cause a hang on error/cancel of the parent
+nursery.
+
+'''
+import trio
+import tractor
+
+
+@tractor.context
+async def sleep(
+    ctx: tractor.Context,
+):
+    await trio.sleep(0.5)
+    await ctx.started()
+    await trio.sleep_forever()
+
+
+async def open_ctx(
+    n: tractor._trionics.ActorNursery
+):
+
+    # spawn both actors
+    portal = await n.start_actor(
+        name='sleeper',
+        enable_modules=[__name__],
+    )
+
+    async with portal.open_context(
+        sleep,
+    ) as (ctx, first):
+        assert first is None
+
+
+async def main():
+
+    async with tractor.open_nursery(
+        debug_mode=True,
+        loglevel='runtime',
+    ) as an:
+
+        async with trio.open_nursery() as n:
+            n.start_soon(open_ctx, an)
+
+            await trio.sleep(0.2)
+            await trio.sleep(0.1)
+            assert 0
+
+
+if __name__ == '__main__':
+    trio.run(main)

examples/debugging/root_timeout_while_child_crashed.py

@@ -0,0 +1,31 @@
+
+import trio
+import tractor
+
+
+async def key_error():
+    "Raise a ``NameError``"
+    return {}['doggy']
+
+
+async def main():
+    """Root dies 
+
+    """
+    async with tractor.open_nursery(
+        debug_mode=True,
+        loglevel='debug'
+    ) as n:
+
+        # spawn both actors
+        portal = await n.run_in_actor(key_error)
+
+        # XXX: originally a bug caused by this is where root would enter
+        # the debugger and clobber the tty used by the repl even though
+        # child should have it locked.
+        with trio.fail_after(1):
+            await trio.Event().wait()
+
+
+if __name__ == '__main__':
+    trio.run(main)

tests/test_debugger.py

@@ -317,32 +317,58 @@ def test_multi_daemon_subactors(spawn, loglevel):
         next_msg = name_error_msg
 
     elif name_error_msg in before:
-        next_msg = None
+        next_msg = bp_forever_msg
 
     else:
         raise ValueError("Neither log msg was found !?")
 
-    child.sendline('c')
+    # NOTE: previously since we did not have clobber prevention
+    # in the root actor this final resume could result in the debugger
+    # tearing down since both child actors would be cancelled and it was
+    # unlikely that `bp_forever` would re-acquire the tty lock again.
+    # Now, we should have a final resumption in the root plus a possible
+    # second entry by `bp_forever`.
 
-    # first name_error failure
+    child.sendline('c')
     child.expect(r"\(Pdb\+\+\)")
     before = str(child.before.decode())
 
-    if next_msg:
-        assert next_msg in before
+    assert next_msg in before
 
-    child.sendline('c')
+    # XXX: hooray the root clobbering the child here was fixed!
+    # IMO, this demonstrates the true power of SC system design.
 
-    child.expect(r"\(Pdb\+\+\)")
-    before = str(child.before.decode())
-    assert "tractor._exceptions.RemoteActorError: ('name_error'" in before
+    # now the root actor won't clobber the bp_forever child
+    # during it's first access to the debug lock, but will instead
+    # wait for the lock to release, by the edge triggered
+    # ``_debug._no_remote_has_tty`` event before sending cancel messages
+    # (via portals) to its underlings B)
+
+    # at some point here there should have been some warning msg from
+    # the root announcing it avoided a clobber of the child's lock, but
+    # it seems unreliable in testing here to gnab it:
+    # assert "in use by child ('bp_forever'," in before
+
+    # wait for final error in root
+    while True:
+
+        child.sendline('c')
+        child.expect(r"\(Pdb\+\+\)")
+        before = str(child.before.decode())
+        try:
+
+            # root error should be packed as remote error
+            assert "_exceptions.RemoteActorError: ('name_error'" in before
+            break
+
+        except AssertionError:
+            assert bp_forever_msg in before
 
     try:
         child.sendline('c')
         child.expect(pexpect.EOF)
 
     except pexpect.exceptions.TIMEOUT:
-
         # Failed to exit using continue..?
         child.sendline('q')
         child.expect(pexpect.EOF)
@@ -386,19 +412,16 @@ def test_multi_subactors_root_errors(spawn):
 def test_multi_nested_subactors_error_through_nurseries(spawn):
     """Verify deeply nested actors that error trigger debugger entries
     at each actor nurserly (level) all the way up the tree.
-    """
 
-    # NOTE: previously, inside this script was a a bug where if the
+    """
+    # NOTE: previously, inside this script was a bug where if the
     # parent errors before a 2-levels-lower actor has released the lock,
     # the parent tries to cancel it but it's stuck in the debugger?
     # A test (below) has now been added to explicitly verify this is
     # fixed.
 
     child = spawn('multi_nested_subactors_error_up_through_nurseries')
 
-    # startup time can be iffy
-    time.sleep(1)
-
     for i in range(12):
         try:
             child.expect(r"\(Pdb\+\+\)")
@@ -471,11 +494,34 @@ def test_root_nursery_cancels_before_child_releases_tty_lock(
 
         child.sendline('c')
 
-    child.expect(pexpect.EOF)
+    while True:
+        try:
+            child.expect(pexpect.EOF)
+            break
+        except pexpect.exceptions.TIMEOUT:
+            print('child was able to grab tty lock again?')
 
     if not timed_out_early:
 
         before = str(child.before.decode())
         assert "tractor._exceptions.RemoteActorError: ('spawner0'" in before
         assert "tractor._exceptions.RemoteActorError: ('name_error'" in before
         assert "NameError: name 'doggypants' is not defined" in before
+
+
+def test_root_cancels_child_context_during_startup(
+    spawn,
+):
+    '''Verify a fast fail in the root doesn't lock up the child reaping
+    and all while using the new context api.
+
+    '''
+    child = spawn('fast_error_in_root_after_spawn')
+
+    child.expect(r"\(Pdb\+\+\)")
+
+    before = str(child.before.decode())
+    assert "AssertionError" in before
+
+    child.sendline('c')
+    child.expect(pexpect.EOF)

tractor/_actor.py

@@ -41,10 +41,6 @@
 log = get_logger('tractor')
 
 
-class ActorFailure(Exception):
-    "General actor failure"
-
-
 async def _invoke(
 
     actor: 'Actor',
@@ -56,8 +52,10 @@ async def _invoke(
         Union[trio.CancelScope, BaseException]
     ] = trio.TASK_STATUS_IGNORED,
 ):
-    """Invoke local func and deliver result(s) over provided channel.
-    """
+    '''Invoke local func and deliver result(s) over provided channel.
+
+    '''
+    __tracebackhide__ = True
     treat_as_gen = False
 
     # possible a traceback (not sure what typing is for this..)