[2.7] bpo-31334: Fix timeout in select.poll.poll() (GH-3277) (#4034)
Always pass -1, or INFTIM where defined, to the poll() system call when
a negative timeout is passed to the poll.poll([timeout]) method in the
select module. Various OSes throw an error with arbitrary negative
values..
(cherry picked from commit 6cfa927ceb931ad968b5b03e4a2bffb64a8a0604)
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index a38aa08..ce4c15b 100644
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -530,6 +530,17 @@
return NULL;
}
+ /* On some OSes, typically BSD-based ones, the timeout parameter of the
+ poll() syscall, when negative, must be exactly INFTIM, where defined,
+ or -1. See issue 31334. */
+ if (timeout < 0) {
+#ifdef INFTIM
+ timeout = INFTIM;
+#else
+ timeout = -1;
+#endif
+ }
+
/* Avoid concurrent poll() invocation, issue 8865 */
if (self->poll_running) {
PyErr_SetString(PyExc_RuntimeError,