Fix: Move rand-compat to private src dir

[userspace-rcu.git] / src / compat-rand.h

diff --git a/src/compat-rand.h b/src/compat-rand.h
new file mode 100644 (file)
index 0000000..7c6acde
--- /dev/null
+++ b/src/compat-rand.h
@@ -0,0 +1,63 @@
+#ifndef _COMPAT_RAND_H
+#define _COMPAT_RAND_H
+
+/*
+ * compat-rand.h
+ *
+ * Userspace RCU library - rand/rand_r Compatibility Header
+ *
+ * Copyright 1996 - Ulrich Drepper <drepper@cygnus.com >
+ * Copyright 2013 - Pierre-Luc St-Charles <pierre-luc.st-charles@polymtl.ca>
+ *
+ * Note: this file is only used to simplify the code required to
+ * use the 'rand_r(...)' system function across multiple platforms,
+ * which might not always be referenced the same way.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifdef __ANDROID__
+/*
+ * Reentrant random function from POSIX.1c.
+ * Copyright (C) 1996, 1999 Free Software Foundation, Inc.
+ * This file is part of the GNU C Library.
+ * Contributed by Ulrich Drepper <drepper@cygnus.com <mailto:drepper@cygnus.com>>, 1996.
+ */
+static inline int rand_r(unsigned int *seed)
+{
+       unsigned int next = *seed;
+       int result;
+
+       next *= 1103515245;
+       next += 12345;
+       result = (unsigned int) (next / 65536) % 2048;
+
+       next *= 1103515245;
+       next += 12345;
+       result <<= 10;
+       result ^= (unsigned int) (next / 65536) % 1024;
+
+       next *= 1103515245;
+       next += 12345;
+       result <<= 10;
+       result ^= (unsigned int) (next / 65536) % 1024;
+
+       *seed = next;
+
+       return result;
+}
+#endif /* __ANDROID__ */
+
+#endif /* _COMPAT_RAND_H */