Ticket #7066: boost_1_50_0_current_thread_tls_key.patch

thread.cpp

@@ -31 +31 @@
 {
     namespace
     {
-#ifdef BOOST_THREAD_PROVIDES_ONCE_CXX11
-        boost::once_flag current_thread_tls_init_flag;
-#else
-        boost::once_flag current_thread_tls_init_flag=BOOST_ONCE_INIT;
+// Windows CE does not define the TLS_OUT_OF_INDEXES constant.
+#ifndef TLS_OUT_OF_INDEXES
+#  define BOOST_THREAD_TLS_OUT_OF_INDEXES_DEFINED
+#  define TLS_OUT_OF_INDEXES 0xFFFFFFFF
 #endif
-        #if defined(UNDER_CE)
-        // Windows CE does not define the TLS_OUT_OF_INDEXES constant.
-        DWORD tls_out_of_index=0xFFFFFFFF;
-        #else
-        DWORD tls_out_of_index=TLS_OUT_OF_INDEXES;
-        #endif
-        DWORD current_thread_tls_key=tls_out_of_index;
+        inline DWORD & get_current_thread_tls_key_ref()
+        {
+            // Static variables at global scope are initialized in a random
+            // order. Thus, we may not initialize current_thread_tls_key at a
+            // global scope or any statically allocated thread_specific_ptr
+            // call may fail. Consider:
+            //   a) A static (at global scope) thread_specific_ptr is
+            //      initialized by some compiler generated code.
+            //   b) create_current_thread_tls_key gets called. TlsAlloc()
+            //      result is stored to current_thread_tls_key. (Assuming no
+            //      errors happen.)
+            //   c) Now a static (at global scope) current_thread_tls_key gets
+            //      initialized (again, by compiler generated code) and thus
+            //      the value we just got from TlsAlloc gets overwritten.
+            //   d) Any following set_current_thread_data() calls will fail as
+            //      current_thread_tls_key is TLS_OUT_OF_INDEXES.
+            static DWORD current_thread_tls_key=TLS_OUT_OF_INDEXES;
+            return current_thread_tls_key;
+        }
 
         void create_current_thread_tls_key()
         {
             tss_cleanup_implemented(); // if anyone uses TSS, we need the cleanup linked in
-            current_thread_tls_key=TlsAlloc();
-            BOOST_ASSERT(current_thread_tls_key!=tls_out_of_index);
+            get_current_thread_tls_key_ref() = TlsAlloc();
+            BOOST_ASSERT(get_current_thread_tls_key_ref()!=TLS_OUT_OF_INDEXES);
         }
 
         void cleanup_tls_key()
         {
-            if(current_thread_tls_key!=tls_out_of_index)
+            if(get_current_thread_tls_key_ref()!=TLS_OUT_OF_INDEXES)
             {
-                TlsFree(current_thread_tls_key);
-                current_thread_tls_key=tls_out_of_index;
+                TlsFree(get_current_thread_tls_key_ref());
+                get_current_thread_tls_key_ref() = TLS_OUT_OF_INDEXES;
             }
         }
 
         detail::thread_data_base* get_current_thread_data()
         {
-            if(current_thread_tls_key==tls_out_of_index)
+            if(get_current_thread_tls_key_ref()==TLS_OUT_OF_INDEXES)
             {
                 return 0;
             }
-            return (detail::thread_data_base*)TlsGetValue(current_thread_tls_key);
+            return (detail::thread_data_base*)TlsGetValue(get_current_thread_tls_key_ref());
         }
 
         void set_current_thread_data(detail::thread_data_base* new_data)
         {
+#ifdef BOOST_THREAD_PROVIDES_ONCE_CXX11
+            static boost::once_flag current_thread_tls_init_flag;
+#else
+            static boost::once_flag current_thread_tls_init_flag=BOOST_ONCE_INIT;
+#endif
             boost::call_once(current_thread_tls_init_flag,create_current_thread_tls_key);
-            if(current_thread_tls_key!=tls_out_of_index)
-                BOOST_VERIFY(TlsSetValue(current_thread_tls_key,new_data));
+            if(get_current_thread_tls_key_ref()!=TLS_OUT_OF_INDEXES)
+                BOOST_VERIFY(TlsSetValue(get_current_thread_tls_key_ref(),new_data));
             else
                 boost::throw_exception(thread_resource_error());
         }
 
+#ifdef BOOST_THREAD_TLS_OUT_OF_INDEXES_DEFINED
+#  undef TLS_OUT_OF_INDEXES
+#  undef BOOST_THREAD_TLS_OUT_OF_INDEXES_DEFINED
+#endif
+
 #ifndef BOOST_HAS_THREADEX
 // Windows CE doesn't define _beginthreadex