Author: Armin Rigo <[email protected]>
Branch: tealet
Changeset: r45394:c60a5d4e0d19
Date: 2011-07-06 19:14 +0200
http://bitbucket.org/pypy/pypy/changeset/c60a5d4e0d19/
Log: A full implementation of greenlets on top of tealets.
diff --git a/lib_pypy/greenlet.py b/lib_pypy/greenlet.py
--- a/lib_pypy/greenlet.py
+++ b/lib_pypy/greenlet.py
@@ -1,1 +1,171 @@
-from _stackless import greenlet
+import tealet, sys
+
+# ____________________________________________________________
+# Exceptions
+
+class GreenletExit(Exception):
+ """This special exception does not propagate to the parent greenlet; it
+can be used to kill a single greenlet."""
+
+error = tealet.error
+
+# ____________________________________________________________
+# Helper function
+
+def getcurrent():
+ "Returns the current greenlet (i.e. the one which called this function)."
+ try:
+ return _tls.current
+ except AttributeError:
+ # first call in this thread: current == main
+ _green_create_main()
+ return _tls.current
+
+# ____________________________________________________________
+# The 'greenlet' class
+
+class greenlet(object):
+ getcurrent = staticmethod(getcurrent)
+ error = error
+ GreenletExit = GreenletExit
+
+ def __new__(cls, *args, **kwds):
+ self = super(greenlet, cls).__new__(cls, *args, **kwds)
+ self.__parent = getcurrent()
+ return self
+
+ def __init__(self, run=None, parent=None):
+ if run is not None:
+ self.run = run
+ if parent is not None:
+ self.parent = parent
+
+ def switch(self, *args):
+ "switch execution to greenlet optionally passing a value, "
+ "return value passed when switching back"
+ _tls.passaround = args
+ oldcurrent = _tls.current
+ target = self
+ while True:
+ if target.__state_active():
+ target.__tealet.switch()
+ break
+ if not target.__state_started():
+ g = _GreenTealet()
+ g.greenlet = target
+ _tls.maintealet.start(g)
+ break
+ target = target.__parent
+ #
+ _tls.current = oldcurrent
+ res = _tls.passaround
+ _tls.passaround = None
+ if _tls.passaround_exception is not None:
+ typ, val, tb = _tls.passaround_exception
+ _tls.passaround_exception = None
+ raise typ, val, tb
+ if len(res) == 1:
+ res = res[0]
+ return res
+
+ def throw(self, typ=GreenletExit, val=None, tb=None):
+ "raise exception in greenlet, return value passed when switching back"
+ if self.__is_dead():
+ # dead greenlet: turn GreenletExit into a regular return
+ if (isinstance(typ, type(GreenletExit)) and
+ issubclass(typ, GreenletExit)):
+ if val is None:
+ return self.switch(typ())
+ if isinstance(val, GreenletExit):
+ return self.switch(val)
+ if isinstance(typ, GreenletExit):
+ return self.switch(typ)
+ #
+ _tls.passaround_exception = (typ, val, tb)
+ return self.switch()
+
+ def __state_started(self):
+ return hasattr(self, '_greenlet__tealet')
+
+ def __state_active(self):
+ return getattr(self, '_greenlet__tealet', None) is not None
+
+ def __nonzero__(self):
+ return self.__state_active()
+
+ def __get_parent(self):
+ return self.__parent
+
+ def __set_parent(self, nparent):
+ if not isinstance(nparent, greenlet):
+ raise TypeError("parent must be a greenlet")
+ p = nparent
+ while p is not None:
+ if p is self:
+ raise ValueError("cyclic parent chain")
+ p = p.__parent
+ self.__parent = nparent
+
+ def __get_gr_frame(self):
+ raise NotImplementedError("attribute 'gr_frame' of greenlet objects")
+
+ def __is_dead(self):
+ return self.__state_started() and not self.__state_active()
+
+ parent = property(__get_parent, __set_parent)
+ gr_frame = property(__get_gr_frame)
+ dead = property(__is_dead)
+
+# ____________________________________________________________
+# Internal stuff
+
+try:
+ from thread import _local
+except ImportError:
+ class _local(object): # assume no threads
+ pass
+
+_tls = _local()
+
+def _green_create_main():
+ # create the main greenlet for this thread
+ _tls.maintealet = tealet.MainTealet()
+ _tls.current = None
+ _tls.passaround_exception = None
+ gmain = greenlet()
+ gmain._greenlet__tealet = _tls.maintealet
+ _tls.current = gmain
+
+class _GreenTealet(tealet.Tealet):
+ def run(self):
+ while True:
+ g = self.greenlet
+ g._greenlet__tealet = self
+ try:
+ try:
+ _tls.current = g
+ args = _tls.passaround
+ _tls.passaround = None
+ if _tls.passaround_exception is not None:
+ typ, val, tb = _tls.passaround_exception
+ _tls.passaround_exception = None
+ raise typ, val, tb
+ res = self.greenlet.run(*args)
+ except GreenletExit, res:
+ pass
+ except:
+ _tls.passaround_exception = sys.exc_info()
+ res = None
+ finally:
+ g._greenlet__tealet = None
+ _tls.passaround = (res,)
+ parent = g._greenlet__parent
+ while True:
+ if parent._greenlet__state_active():
+ return parent._greenlet__tealet
+ if parent._greenlet__state_started():
+ parent = parent._greenlet__parent # dead, try the parent
+ else:
+ # not started yet. Start it now.
+ self.greenlet = parent
+ break
_______________________________________________
pypy-commit mailing list
[email protected]
http://mail.python.org/mailman/listinfo/pypy-commit
