From f990a51163275f22b77c91d10d1a9193fdaa40e6 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Jos=C3=A9=20Fonseca?= <jose.r.fonseca@gmail.com>
Date: Tue, 23 Apr 2013 09:42:48 +0100
Subject: [PATCH] Revert "Remove os::thread_specific_ptr"

This reverts commit 67ec200baea241d55bea33c43fd5194d90d9e401.
---
 common/os_thread.hpp | 81 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 80 insertions(+), 1 deletion(-)

diff --git a/common/os_thread.hpp b/common/os_thread.hpp
index 2c3f732..5ec7f5d 100644
--- a/common/os_thread.hpp
+++ b/common/os_thread.hpp
@@ -26,7 +26,7 @@
 /*
  * OS native thread abstraction.
  *
- * Mimics C++11 threads.
+ * Mimics C++11 / boost threads.
  */
 
 #ifndef _OS_THREAD_HPP_
@@ -283,6 +283,85 @@ namespace os {
     };
 
 
+    /**
+     * Same interface as boost::thread_specific_ptr.
+     */
+    template <typename T>
+    class thread_specific_ptr
+    {
+    private:
+#ifdef _WIN32
+        DWORD dwTlsIndex;
+#else
+        pthread_key_t key;
+
+        static void destructor(void *ptr) {
+            delete static_cast<T *>(ptr);
+        }
+#endif
+
+    public:
+        thread_specific_ptr(void) {
+#ifdef _WIN32
+            dwTlsIndex = TlsAlloc();
+#else
+            pthread_key_create(&key, &destructor);
+#endif
+        }
+
+        ~thread_specific_ptr() {
+#ifdef _WIN32
+            TlsFree(dwTlsIndex);
+#else
+            pthread_key_delete(key);
+#endif
+        }
+
+        T* get(void) const {
+            void *ptr;
+#ifdef _WIN32
+            ptr = TlsGetValue(dwTlsIndex);
+#else
+            ptr = pthread_getspecific(key);
+#endif
+            return static_cast<T*>(ptr);
+        }
+
+        T* operator -> (void) const
+        {
+            return get();
+        }
+
+        T& operator * (void) const
+        {
+            return *get();
+        }
+
+        void reset(T* new_value=0) {
+            T * old_value = get();
+            set(new_value);
+            if (old_value) {
+                delete old_value;
+            }
+        }
+
+        T* release (void) {
+            T * old_value = get();
+            set(0);
+            return old_value;
+        }
+
+private:
+        void set(T* new_value) {
+#ifdef _WIN32
+            TlsSetValue(dwTlsIndex, new_value);
+#else
+            pthread_setspecific(key, new_value);
+#endif
+        }
+    };
+
+
     /**
      * Same interface as std::thread
      */
-- 
2.43.0