From e4710cfcedbecbd3bfa154c2586415ab5b6e28bc Mon Sep 17 00:00:00 2001 From: Brett Cannon Date: Thu, 15 Nov 2012 21:39:36 -0500 Subject: Issue #15894: Document why we don't worry about re-acquiring the global import lock after forking. --- Python/import.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/Python/import.c b/Python/import.c index 2f71b97..6882b57 100644 --- a/Python/import.c +++ b/Python/import.c @@ -202,8 +202,11 @@ _PyImport_ReInitLock(void) if (import_lock_level > 1) { /* Forked as a side effect of import */ long me = PyThread_get_thread_ident(); - PyThread_acquire_lock(import_lock, 0); - /* XXX: can the previous line fail? */ + /* The following could fail if the lock is already held, but forking as + a side-effect of an import is a) rare, b) nuts, and c) difficult to + do thanks to the lock only being held when doing individual module + locks per import. */ + PyThread_acquire_lock(import_lock, NOWAIT_LOCK); import_lock_thread = me; import_lock_level--; } else { -- cgit v0.12