1 files changed, 79 insertions, 0 deletions
diff --git a/stat_t.hh b/stat_t.hh
new file mode 100644
index 0000000..d318c98
--- /dev/null
+++ b/stat_t.hh
@@ -0,0 +1,79 @@
+/*
+ * This file is part of PowerDNS or dnsdist.
+ * Copyright -- PowerDNS.COM B.V. and its contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * In addition, for the avoidance of any doubt, permission is granted to
+ * link this program with OpenSSL and to (re)distribute the binaries
+ * produced as the result of such linking.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#pragma once
+
+#include <atomic>
+
+#define CPU_LEVEL1_DCACHE_LINESIZE 64 // Until we know better via configure/getconf
+
+namespace pdns {
+  template <typename T>
+  class stat_t_trait {
+  public:
+    typedef T base_t;
+    typedef std::atomic<base_t> atomic_t;
+
+    stat_t_trait() : stat_t_trait(base_t(0)) {
+    }
+    stat_t_trait(const base_t x) {
+      new(&counter) atomic_t(x);
+    }
+    ~stat_t_trait() {
+      reinterpret_cast<atomic_t *>(&counter)->~atomic_t();
+    }
+    stat_t_trait(const stat_t_trait&) = delete;
+    base_t operator++(int) {
+      return (*reinterpret_cast<atomic_t *>(&counter))++;
+    }
+    base_t operator++() {
+      return ++(*reinterpret_cast<atomic_t *>(&counter));
+    }
+    base_t operator--(int) {
+      return (*reinterpret_cast<atomic_t *>(&counter))--;
+    }
+    base_t operator--() {
+      return --(*reinterpret_cast<atomic_t *>(&counter));
+    }
+    base_t operator+=(const stat_t_trait& v) {
+      return *reinterpret_cast<atomic_t *>(&counter) += *reinterpret_cast<const atomic_t *>(&v.counter);
+    }
+    base_t operator-=(const stat_t_trait& v) {
+      return *reinterpret_cast<atomic_t *>(&counter) -= *reinterpret_cast<const atomic_t *>(&v.counter);
+    }
+    base_t load() const {
+      return reinterpret_cast<const atomic_t *>(&counter)->load();
+    }
+    void store(base_t v) {
+      reinterpret_cast<atomic_t *>(&counter)->store(v);
+    }
+    operator base_t() const {
+      return reinterpret_cast<const atomic_t *>(&counter)->load();
+    }
+
+  private:
+    typename std::aligned_storage<sizeof(base_t), CPU_LEVEL1_DCACHE_LINESIZE>::type counter;
+  };
+
+  typedef stat_t_trait<uint64_t> stat_t;
+  typedef stat_t_trait<uint32_t> stat32_t;
+  typedef stat_t_trait<uint16_t> stat16_t;
+}