wip: ungather; to do overview

awaitwhat/__init__.py

@@ -1,6 +1,7 @@
 from asyncio.base_tasks import _task_print_stack, _task_get_stack
 import types
 from . import _what
+from . import gather
 
 
 class FakeCode:
@@ -19,6 +20,7 @@ def __init__(self, name):
         self.f_code = FakeCode(name)
 
 
+# FIXME: what order is the stack in, as in, is it reversed?
 def extend_stack(s, limit=None):
     stack = s[:]
     while isinstance(stack[-1], types.FrameType):
@@ -66,3 +68,28 @@ def get_stack(self, limit=None):
 
 def task_print_stack(task, limit, file):
     return _task_print_stack(Wrapper(task), limit, file)
+
+
+# FIXME: what can be awaited:
+#
+# - coro (done)
+# - Task (enumerated, but needs a bridge)
+# - Future (naked, unclear who ought to resolve it)
+# - Event (e.wait() is a coro, but needs a bridge?)
+# - gather (via callback)
+# - shield (via callback)
+# - asyncio.run (via callback)
+#
+# - TaskWakeupMethWrapper (via callback)
+# - bridge FutureIter to Future (or just rely on Task wait_for=<...>
+
+# FIXME: callbacks:
+#
+# top-level event loop thing:
+# cb=[_run_until_complete_cb() at /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/asyncio/base_events.py:158
+#
+# gather:
+# cb=[gather.<locals>._done_callback() at /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/asyncio/tasks.py:664
+#
+# shield:
+# ...

awaitwhat/gather.py

@@ -0,0 +1,29 @@
+import inspect
+
+# work in progress:
+
+# when a task is ultimately waiting on gather(), _done_callback is visible.
+
+
+def decipher_done_callback(done_callback):
+    closure = inspect.getclosurevars(done_callback).nonlocals
+    state = f"progress: {closure['nfinished']}/{closure['nfuts']}"
+    future = closure["outer"]
+    print(future, state)
+    children = closure["children"]
+    for child in children:
+        if child.done():
+            # resolved, exception, cancelled
+            if child.cancelled():
+                print(child, "cancelled")
+            elif child.exception():
+                print(child, child.exception())
+            else:
+                print(child, child.result())
+        else:
+            print(child, "pending")
+
+
+def task_callback(t):
+    # FIXME: there may be several; py 3.8 vs py 3.7
+    return t._callbacks[0][0]

test/test.py

@@ -1,20 +1,29 @@
 import asyncio
-import linecache
-from awaitwhat import extend_stack, _task_print_stack, task_print_stack
+import awaitwhat
 import sys
 
 
 def trace_all_tasks():
     print("### Python native task stack traces")
     for t in asyncio.Task.all_tasks():
-        _task_print_stack(t, None, sys.stdout)
+        asyncio.base_tasks._task_print_stack(t, None, sys.stdout)
         print()
 
     print("### Extended task stack traces")
     for t in asyncio.Task.all_tasks():
-        task_print_stack(t, None, sys.stdout)
+        awaitwhat.task_print_stack(t, None, sys.stdout)
         print()
 
+    tt = asyncio.Task.all_tasks()
+    t = list(tt)[0]
+    print(t)
+    cb = awaitwhat.gather.task_callback(t)
+    try:
+        awaitwhat.gather.decipher_done_callback(cb)
+    except Exception as e:
+        print("failed to decipher", e)
+    __import__("pdb").set_trace()
+
 
 async def tester():
     await asyncio.sleep(0.1)