Adding upstream version 0.6.0.upstream/0.6.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/include/ck_backoff.h b/include/ck_backoff.h
new file mode 100644
index 0000000..82a4f21
--- /dev/null
+++ b/include/ck_backoff.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2009-2015 Samy Al Bahra.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * 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.
+ */
+
+#ifndef CK_BACKOFF_H
+#define CK_BACKOFF_H
+
+#include <ck_cc.h>
+#include <ck_pr.h>
+
+#ifndef CK_BACKOFF_CEILING
+#define CK_BACKOFF_CEILING ((1 << 20) - 1)
+#endif
+
+#define CK_BACKOFF_INITIALIZER (1 << 9)
+
+typedef unsigned int ck_backoff_t;
+
+/*
+ * This is a exponential back-off implementation.
+ */
+CK_CC_INLINE static void
+ck_backoff_eb(unsigned int *c)
+{
+	unsigned int i, ceiling;
+
+	ceiling = *c;
+	for (i = 0; i < ceiling; i++)
+		ck_pr_barrier();
+
+	*c = ceiling <<= ceiling < CK_BACKOFF_CEILING;
+	return;
+}
+
+#endif /* CK_BACKOFF_H */