thread: Test for pending cancellation requests before select()ing on OS X

This fixes some vici test cases on OS X, where the test thread tries to cancel
the watcher thread during cleanup, but fails as select() does not honor the
pre-issued cancellation request.

diff --git a/src/libstrongswan/threading/thread.h b/src/libstrongswan/threading/thread.h
index 8d3c30e9ba695cb4a37851f9720da719cc2a5dee..6abb834110041e7287138c0484d2cf8da56eb126 100644 (file)
--- a/src/libstrongswan/threading/thread.h
+++ b/src/libstrongswan/threading/thread.h
@@ -189,4 +189,32 @@ void threads_init();
  */
 void threads_deinit();
 
+
+#ifdef __APPLE__
+
+/*
+ * While select() is a cancellation point, it seems that OS X does not honor
+ * pending cancellation points when entering the function. We manually test for
+ * and honor pending cancellation requests, but this obviously can't prevent
+ * some race conditions where the the cancellation happens after the check,
+ * but before the select.
+ */
+static inline int precancellable_select(int nfds, fd_set *restrict readfds,
+                                               fd_set *restrict writefds, fd_set *restrict errorfds,
+                                               struct timeval *restrict timeout)
+{
+       if (thread_cancelability(TRUE))
+       {
+               thread_cancellation_point();
+       }
+       else
+       {
+               thread_cancelability(FALSE);
+       }
+       return select(nfds, readfds, writefds, errorfds, timeout);
+}
+#define select precancellable_select
+
+#endif /* __APPLE__ */
+
 #endif /** THREADING_THREAD_H_ @} */