[Python-Dev] tests failing in 2.2.2 (original) (raw)

Tim Peters tim@zope.com
Tue, 8 Oct 2002 16:15:16 -0400

[Guido, on the list(xrange(maxint // 4)) test]

That's strange -- that test is specifically designed to fail before it ever gets to allocating memory. Can you track this down with a debugger?

[Martin]

Notice that this test does not strictly achieve that:

This is true, although I'd say it plain doesn't achieve that, and leave "strictly" out of it.

with a four-byte pointer, you attempt to allocate 0x20000000L items (due to roundupsize), which is small enough to try a realloc. In turn, it tries to allocate 0x80000000L bytes, i.e. 2GB. On a 32-bit machine, it is possible to allocate that much memory.

Depending on platform, of course. Under MSVC6, it does call the platform realloc(), and it's the latter that returns a NULL pointer (the max you can alloc under Win32 is 0x7ffdefff).

If we changed the test to use maxint // 2 instead, it would (just barely) trigger the

_new_size <= ((~(size_t)0) / sizeof(type))

test in NRESIZE instead, and keep the platform realloc() out of it.

Good enough?