[Python-Dev] Issue #10348: concurrent.futures doesn't work on BSD (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Thu Dec 30 10:16:43 CET 2010

Am 30.12.2010 04:45, schrieb Brian Quinlan:

On Dec 29, 2010, at 2:55 PM, Victor Stinner wrote:

Le mercredi 29 décembre 2010 à 21:49 +0100, "Martin v. Löwis" a écrit : Of course, one may wonder why testfirstcompleted manages to create 41 SemLock objects, when all it tries to do is two future calls.

More numbers (on Linux): - Queue: 3 SemLock - Condition: 4 SemLock - Event: 5 SemLock - Call (testconcurrentfutures): 10 SemLock (2 Event) - ProcessPoolExecutor: 11 SemLock (2 Queue, 1 Condition) FreeBSD 7.2 is limited to 30 semaphores, so with ProcessPoolExecutor, you can only create one Call object, whereas some tests use 4 Call objects or more. Great detective work! This would suggest that ProcessPoolExecutors are useable on FreeBSD 7.2 so long as the user doesn't create more than two at once (which probably isn't a big deal for most apps).

IIUC, this is a system-wide limit. So if you run any non-trivial app a number of times will quickly cause failure. This is just not practical.

So skipping the test is probably the way to go.

I'm still -1 on that proposal.

Regards, Martin

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