1 files changed, 45 insertions, 0 deletions
diff --git a/libc/stdio/__fsetlocking.c b/libc/stdio/__fsetlocking.c
new file mode 100644
index 000000000..f49503207
--- /dev/null
+++ b/libc/stdio/__fsetlocking.c
@@ -0,0 +1,45 @@
+/* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
+ *
+ * GNU Library General Public License (LGPL) version 2 or later.
+ *
+ * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
+ */
+
+#include "_stdio.h"
+#include <stdio_ext.h>
+
+/* Not threadsafe. */
+
+/* Notes:
+ *   When setting the locking mode, glibc returns the previous setting.
+ *   glibc treats invalid locking_mode args as FSETLOCKING_INTERNAL.
+ */
+
+int __fsetlocking(FILE *stream, int locking_mode)
+{
+#ifdef __UCLIBC_HAS_THREADS__
+	int current = 1 + (stream->__user_locking & 1);
+
+	/* Check constant assumptions.  We can't test at build time
+	 * since these are enums. */
+	assert((FSETLOCKING_QUERY == 0) && (FSETLOCKING_INTERNAL == 1)
+		   && (FSETLOCKING_BYCALLER == 2));
+
+	__STDIO_STREAM_VALIDATE(stream);
+	assert(((unsigned int) locking_mode) <= 2);
+
+	if (locking_mode != FSETLOCKING_QUERY) {
+		stream->__user_locking = ((locking_mode == FSETLOCKING_BYCALLER)
+								  ? 1
+								  : _stdio_user_locking); /* 0 or 2 */
+		__STDIO_STREAM_VALIDATE(stream);
+	}
+
+	return current;
+#else
+	__STDIO_STREAM_VALIDATE(stream);
+	assert(((unsigned int) locking_mode) <= 2);
+
+	return FSETLOCKING_INTERNAL;
+#endif
+}