1 files changed, 71 insertions, 0 deletions
diff --git a/utils/threadlocal.h b/utils/threadlocal.h
new file mode 100755
index 00000000..d79f5d9d
--- /dev/null
+++ b/utils/threadlocal.h
@@ -0,0 +1,71 @@
+#ifndef THREADLOCAL_H
+#define THREADLOCAL_H
+
+#ifndef SETLOCAL_SWAP
+# define SETLOCAL_SWAP 0
+#endif
+
+#ifdef BOOST_NO_MT
+
+# define THREADLOCAL
+
+#else
+
+#ifdef _MSC_VER
+
+//FIXME: doesn't work with DLLs ... use TLS apis instead (http://www.boost.org/libs/thread/doc/tss.html)
+# define THREADLOCAL __declspec(thread)
+
+#else
+
+# define THREADLOCAL __thread
+
+#endif
+
+#endif
+
+#include <algorithm> //swap
+
+// naturally, the below are only thread-safe if value is THREADLOCAL
+template <class D>
+struct SaveLocal {
+    D &value;
+    D old_value;
+    SaveLocal(D& val) : value(val), old_value(val) {}
+    ~SaveLocal() {
+#if SETLOCAL_SWAP
+      swap(value,old_value);
+#else
+      value=old_value;
+#endif
+    }
+};
+
+template <class D>
+struct SetLocal {
+    D &value;
+    D old_value;
+    SetLocal(D& val,const D &new_value) : value(val), old_value(
+#if SETLOCAL_SWAP
+      new_value
+#else
+      val
+#endif
+      ) {
+#if SETLOCAL_SWAP
+      swap(value,old_value);
+#else
+      value=new_value;
+#endif
+    }
+    ~SetLocal() {
+#if SETLOCAL_SWAP
+      swap(value,old_value);
+#else
+      value=old_value;
+#endif
+    }
+};
+
+
+#endif