notify: set lower bound for notify stack size

Some OSes have ridiculously low boundaries and we don't
want mysterious failures on them

1 files changed, 14 insertions, 4 deletions

diff --git a/ext/posix_mq/posix_mq.c b/ext/posix_mq/posix_mq.c
index df667e3..66f3f99 100644
--- a/ext/posix_mq/posix_mq.c
+++ b/ext/posix_mq/posix_mq.c
@@ -850,6 +850,19 @@ static void my_mq_notify(mqd_t des, struct sigevent *not)
         }
 }
 
+static void lower_stack_size(pthread_attr_t *attr)
+{
+/* some OSes have ridiculously small stack sizes */
+#ifdef PTHREAD_STACK_MIN
+        size_t stack_size = PTHREAD_STACK_MIN;
+        size_t min_size = 4096;
+
+        if (stack_size < min_size)
+                stack_size = min_size;
+        pthread_attr_setstacksize(attr, stack_size);
+#endif
+}
+
 /* :nodoc: */
 static VALUE setnotify_exec(VALUE self, VALUE io, VALUE thr)
 {
@@ -864,10 +877,7 @@ static VALUE setnotify_exec(VALUE self, VALUE io, VALUE thr)
         errno = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
         if (errno) rb_sys_fail("pthread_attr_setdetachstate");
 
-#ifdef PTHREAD_STACK_MIN
-        (void)pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN);
-#endif
-
+        lower_stack_size(&attr);
         not.sigev_notify = SIGEV_THREAD;
         not.sigev_notify_function = thread_notify_fd;
         not.sigev_notify_attributes = &attr;