> So I'd like to know: how do these other implementations handle concurrency
> matters for their primitive types, and prevent them from getting corrupted
> in multithreaded programs (if they do) ? I'm not only thinking about python
> types, but also primitive containers and types used in .Net and Java VMs,
> which aren't atomic elements either at an assembly-level point of view.
Well, they definitely have some shortcomings:
test.py:
from threading import Thread
class X(object):
pass
obj = X()
obj.x = 0
def f(*args):
for i in range(10000):
obj.x += 1
threads = []
for i in range(100):
t = Thread(target=f)
threads.append(t)
t.start()
for t in threads:
while t.isAlive():
t.join(1)
print(obj.x)
> python test.py
1000000
> pypy test.py
1000000
> jython-2.5 test.py
19217
> ipy test.py
59040
Not that this thing is reasonable to do in real code, but cpython and
other implementations with GIL at least give you some safety margin.
--
With best regards,
Daniel Kluev
--
http://mail.python.org/mailman/listinfo/python-list
