Implement readdir_r. Audit for proper thread safety and locking.

 -Erik

1 files changed, 63 insertions, 0 deletions

diff --git a/libc/misc/dirent/readdir_r.c b/libc/misc/dirent/readdir_r.c
new file mode 100644
index 000000000..9d9db0dee
--- /dev/null
+++ b/libc/misc/dirent/readdir_r.c
@@ -0,0 +1,63 @@
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <dirent.h>
+#include "dirstream.h"
+
+extern int getdents __P ((unsigned int fd, struct dirent *dirp, unsigned int count));
+
+
+int readdir_r(DIR *dir, struct dirent *entry, struct dirent **result)
+{
+	int ret;
+	ssize_t bytes;
+	struct dirent *de;
+
+	if (!dir) {
+	    __set_errno(EBADF);
+	    return(EBADF);
+	}
+	de = NULL;
+
+#ifdef _POSIX_THREADS
+	pthread_mutex_lock(dir->dd_lock);
+#endif
+
+	do {
+	    if (dir->dd_size <= dir->dd_nextloc) {
+		/* read dir->dd_max bytes of directory entries. */
+		bytes = getdents(dir->dd_fd, dir->dd_buf, dir->dd_max);
+		if (bytes <= 0) {
+		    *result = NULL;
+		    ret = errno;
+		    goto all_done;
+		}
+		dir->dd_size = bytes;
+		dir->dd_nextloc = 0;
+	    }
+
+	    de = (struct dirent *) (((char *) dir->dd_buf) + dir->dd_nextloc);
+
+	    /* Am I right? H.J. */
+	    dir->dd_nextloc += de->d_reclen;
+
+	    /* We have to save the next offset here. */
+	    dir->dd_nextoff = de->d_off;
+	    /* Skip deleted files.  */
+	} while (de->d_ino == 0);
+
+	if (de == NULL) {
+	    *result = NULL;
+	} else {
+	    *result = memcpy (entry, de, de->d_reclen);
+	}
+	ret = 0;
+
+all_done:
+
+#ifdef _POSIX_THREADS
+	pthread_mutex_unlock(dir->dd_lock);
+#endif
+        return((de != NULL)? 0 : ret);
+}