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, 44 insertions, 0 deletions

diff --git a/lib/libc/gen/readdir.c b/lib/libc/gen/readdir.c
index ab3a404..74246b9 100644
--- a/lib/libc/gen/readdir.c
+++ b/lib/libc/gen/readdir.c
@@ -29,6 +29,9 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ *
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
@@ -37,6 +40,11 @@ static char sccsid[] = "@(#)readdir.c	8.3 (Berkeley) 9/29/94";
 
 #include <sys/param.h>
 #include <dirent.h>
+#include <errno.h>
+#ifdef _THREAD_SAFE
+#include <pthread.h>
+#include "pthread_private.h"
+#endif _THREAD_SAFE
 
 /*
  * get next entry in a directory.
@@ -73,3 +81,39 @@ readdir(dirp)
 		return (dp);
 	}
 }
+
+int
+readdir_r(dirp, entry, result)
+	DIR *dirp;
+	struct dirent *entry;
+	struct dirent **result;
+{
+	struct dirent *dp;
+	int ret;
+
+	if (dirp->dd_fd < 0) {
+		return EBADF;
+	}
+#ifdef _THREAD_SAFE
+	if ((ret = _FD_LOCK(dirp->dd_fd, FD_READ, NULL)) != 0)
+		return ret;
+#endif
+	errno = 0;
+	dp = readdir(dirp);
+	if (dp == NULL && errno != 0) {
+#ifdef _THREAD_SAFE
+		_FD_UNLOCK(dirp->dd_fd, FD_READ);
+#endif
+		return errno;
+	}
+	if (dp != NULL) 
+		memcpy(entry, dp, sizeof *entry);
+#ifdef _THREAD_SAFE
+	_FD_UNLOCK(dirp->dd_fd, FD_READ);
+#endif
+	if (dp != NULL)
+	*result = entry;
+	else
+		*result = NULL;
+	return 0;
+}