Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/greenlet/tests/fail_switch_three_greenlets.py

@@ -0,0 +1,44 @@
+"""
+Uses a trace function to switch greenlets at unexpected times.
+
+In the trace function, we switch from the current greenlet to another
+greenlet, which switches
+"""
+import greenlet
+
+g1 = None
+g2 = None
+
+switch_to_g2 = False
+
+def tracefunc(*args):
+    print('TRACE', *args)
+    global switch_to_g2
+    if switch_to_g2:
+        switch_to_g2 = False
+        g2.switch()
+    print('\tLEAVE TRACE', *args)
+
+def g1_run():
+    print('In g1_run')
+    global switch_to_g2
+    switch_to_g2 = True
+    from_parent = greenlet.getcurrent().parent.switch()
+    print('Return to g1_run')
+    print('From parent', from_parent)
+
+def g2_run():
+    #g1.switch()
+    greenlet.getcurrent().parent.switch()
+
+greenlet.settrace(tracefunc)
+
+g1 = greenlet.greenlet(g1_run)
+g2 = greenlet.greenlet(g2_run)
+
+# This switch didn't actually finish!
+# And if it did, it would raise TypeError
+# because g1_run() doesn't take any arguments.
+g1.switch(1)
+print('Back in main')
+g1.switch(2)