add pthread_cancel, obtained from OpenBSD.

eischen (Daniel Eischen) added wrappers to protect against cancled
threads orphaning internal resources.

the cancelability code is still a bit fuzzy but works for test
programs of my own, OpenBSD's and some examples from ORA's books.

add readdir_r to both libc and libc_r

add some 'const' attributes to function parameters

Reviewed by: eischen, jasone

1 files changed, 40 insertions, 0 deletions

diff --git a/lib/libpthread/thread/thr_msync.c b/lib/libpthread/thread/thr_msync.c
new file mode 100644
index 0000000..209286d
--- /dev/null
+++ b/lib/libpthread/thread/thr_msync.c
@@ -0,0 +1,40 @@
+/*
+ * David Leonard <d@openbsd.org>, 1999. Public Domain.
+ *
+ * $OpenBSD: uthread_msync.c,v 1.2 1999/06/09 07:16:17 d Exp $
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#ifdef _THREAD_SAFE
+#include <pthread.h>
+#include "pthread_private.h"
+
+int
+msync(addr, len, flags)
+	void *addr;
+	size_t len;
+	int flags;
+{
+	int ret;
+
+	/*
+	 * XXX This is quite pointless unless we know how to get the
+	 * file descriptor associated with the memory, and lock it for
+	 * write. The only real use of this wrapper is to guarantee
+	 * a cancellation point, as per the standard. sigh.
+	 */
+
+	/* This is a cancellation point: */
+	_thread_enter_cancellation_point();
+
+	ret = _thread_sys_msync(addr, len, flags);
+
+	/* No longer in a cancellation point: */
+	_thread_leave_cancellation_point();
+
+	return (ret);
+}
+#endif