1 files changed, 79 insertions, 0 deletions
diff --git a/base/random.cc b/base/random.cc
new file mode 100644
index 000000000..42a169c06
--- /dev/null
+++ b/base/random.cc
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+/*
+ * Copyright (c) 2003 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * 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;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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.
+ */
+
+#include <cstdlib>
+#include <cmath>
+
+#include "param.hh"
+#include "random.hh"
+
+using namespace std;
+
+class RandomContext : public ParamContext
+{
+  public:
+    RandomContext(const string &_iniSection)
+        : ::ParamContext(_iniSection) {}
+    ~RandomContext();
+
+    void checkParams();
+};
+
+RandomContext paramContext("random");
+
+Param<unsigned>
+seed(&paramContext, "seed", "seed to random number generator", 1);
+
+void
+RandomContext::checkParams()
+{
+    ::srandom(seed);
+}
+
+long
+getLong()
+{
+    return random();
+}
+
+// idea for generating a double from erand48
+double
+getDouble()
+{
+    union {
+        uint32_t _long[2];
+        uint16_t _short[4];
+    };
+
+    _long[0] = random();
+    _long[1] = random();
+
+    return ldexp((double) _short[0], -48) +
+        ldexp((double) _short[1], -32) +
+        ldexp((double) _short[2], -16);
+}