1 files changed, 56 insertions, 0 deletions
diff --git a/servers/slapd/back-bdb/trans.c b/servers/slapd/back-bdb/trans.c
new file mode 100644
index 0000000..92da8be
--- /dev/null
+++ b/servers/slapd/back-bdb/trans.c
@@ -0,0 +1,56 @@
+/* trans.c - bdb backend transaction routines */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2000-2021 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+#include <ac/string.h>
+
+#include "back-bdb.h"
+#include "lber_pvt.h"
+#include "lutil.h"
+
+
+/* Congestion avoidance code
+ * for Deadlock Rollback
+ */
+
+void
+bdb_trans_backoff( int num_retries )
+{
+	int i;
+	int delay = 0;
+	int pow_retries = 1;
+	unsigned long key = 0;
+	unsigned long max_key = -1;
+	struct timeval timeout;
+
+	lutil_entropy( (unsigned char *) &key, sizeof( unsigned long ));
+
+	for ( i = 0; i < num_retries; i++ ) {
+		if ( i >= 5 ) break;
+		pow_retries *= 4;
+	}
+
+	delay = 16384 * (key * (double) pow_retries / (double) max_key);
+	delay = delay ? delay : 1;
+
+	Debug( LDAP_DEBUG_TRACE,  "delay = %d, num_retries = %d\n", delay, num_retries, 0 );
+
+	timeout.tv_sec = delay / 1000000;
+	timeout.tv_usec = delay % 1000000;
+	select( 0, NULL, NULL, NULL, &timeout );
+}