[pypy-svn] r34655 - pypy/dist/demo

[arigo at codespeak.net]

Author: arigo
Date: Thu Nov 16 11:36:56 2006
New Revision: 34655

Added:
   pypy/dist/demo/pickle_coroutine.py
Log:
A stackless coroutine pickling demo.


Added: pypy/dist/demo/pickle_coroutine.py
==============================================================================
--- (empty file)
+++ pypy/dist/demo/pickle_coroutine.py	Thu Nov 16 11:36:56 2006
@@ -0,0 +1,84 @@
+"""
+Stackless demo.
+
+This example only works on top of a pypy-c compiled with stackless features
+and the signal module:
+
+    translate.py --stackless targetpypystandalone --withmod-signal
+
+Usage:
+
+    pypy-c pickle_coroutine.py --start demo.pickle
+
+        Start the computation.  You can interrupt it at any time by
+        pressing Ctrl-C; at this point, the state of the computing
+        coroutine is saved in demo.pickle.
+
+    pypy-c pickle_coroutine.py --resume demo.pickle
+
+        Reload the coroutine from demo.pickle and continue running it.
+        (It can be interrupted again with Ctrl-C.)
+"""
+
+try:
+    import sys, pickle, signal
+    from stackless import coroutine
+except ImportError:
+    print __doc__
+    sys.exit(2)
+
+
+def ackermann(x, y):
+    check()
+    if x == 0:
+        return y + 1
+    if y == 0:
+        return ackermann(x - 1, 1)
+    return ackermann(x - 1, ackermann(x, y - 1))
+
+# ____________________________________________________________
+
+main = coroutine.getcurrent()
+sys.setrecursionlimit(100000)
+
+interrupt_flag = False
+
+def interrupt_handler(*args):
+    global interrupt_flag
+    interrupt_flag = True
+
+def check():
+    if interrupt_flag:
+        main.switch()
+
+
+def execute(coro):
+    signal.signal(signal.SIGINT, interrupt_handler)
+    res = coro.switch()
+    if res is None and coro.is_alive:    # interrupted!
+        print "interrupted! writing %s..." % (filename,)
+        f = open(filename, 'w')
+        pickle.dump(coro, f)
+        f.close()
+        print "done"
+    else:
+        print "result:", res
+
+try:
+    operation, filename = sys.argv[1:]
+except ValueError:
+    print __doc__
+    sys.exit(2)
+
+if operation == '--start':
+    coro = coroutine()
+    coro.bind(ackermann, 3, 7)
+    print "running from the start..."
+    execute(coro)
+elif operation == '--resume':
+    print "reloading %s..." % (filename,)
+    f = open(filename)
+    coro = pickle.load(f)
+    f.close()
+    print "done, running now..."
+    execute(coro)