From 8334f4e68a992dce2ea076bb55d3758d02b37bc1 Mon Sep 17 00:00:00 2001
From: "Vicente J. Botet Escriba" <vicente.botet@wanadoo.fr>
Date: Sun, 12 Aug 2012 18:31:09 +0000
Subject: [PATCH] Thread: name type for pthread/once epoch so that we can
 choose better an /atomic/ type for it

[SVN r79984]
---
 include/boost/thread/pthread/once.hpp | 22 ++++++++++++++--------
 src/pthread/once.cpp                  | 10 +++++-----
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/include/boost/thread/pthread/once.hpp b/include/boost/thread/pthread/once.hpp
index 80aa09ee..bc3b5b7c 100644
--- a/include/boost/thread/pthread/once.hpp
+++ b/include/boost/thread/pthread/once.hpp
@@ -25,6 +25,12 @@ namespace boost
 
 #define BOOST_ONCE_INITIAL_FLAG_VALUE 0
 
+  namespace thread_detail
+  {
+    typedef unsigned long  uintmax_atomic_t;
+#define BOOST_THREAD_DETAIL_UINTMAX_ATOMIC_C(value) value##ul
+  }
+
 #ifdef BOOST_THREAD_PROVIDES_ONCE_CXX11
 
   struct once_flag
@@ -34,7 +40,7 @@ namespace boost
         : epoch(BOOST_ONCE_INITIAL_FLAG_VALUE)
       {}
   private:
-      boost::uintmax_t epoch;
+      volatile thread_detail::uintmax_atomic_t epoch;
       template<typename Function>
       friend
       void call_once(once_flag& flag,Function f);
@@ -44,7 +50,7 @@ namespace boost
 
     struct once_flag
     {
-        boost::uintmax_t epoch;
+      volatile thread_detail::uintmax_atomic_t epoch;
     };
 
 #define BOOST_ONCE_INIT {BOOST_ONCE_INITIAL_FLAG_VALUE}
@@ -52,8 +58,8 @@ namespace boost
 
     namespace detail
     {
-        BOOST_THREAD_DECL boost::uintmax_t& get_once_per_thread_epoch();
-        BOOST_THREAD_DECL extern boost::uintmax_t once_global_epoch;
+        BOOST_THREAD_DECL thread_detail::uintmax_atomic_t& get_once_per_thread_epoch();
+        BOOST_THREAD_DECL extern thread_detail::uintmax_atomic_t once_global_epoch;
         BOOST_THREAD_DECL extern pthread_mutex_t once_epoch_mutex;
         BOOST_THREAD_DECL extern pthread_cond_t once_epoch_cv;
     }
@@ -63,10 +69,10 @@ namespace boost
     template<typename Function>
     void call_once(once_flag& flag,Function f)
     {
-        static boost::uintmax_t const uninitialized_flag=BOOST_ONCE_INITIAL_FLAG_VALUE;
-        static boost::uintmax_t const being_initialized=uninitialized_flag+1;
-        boost::uintmax_t const epoch=flag.epoch;
-        boost::uintmax_t& this_thread_epoch=detail::get_once_per_thread_epoch();
+        static thread_detail::uintmax_atomic_t const uninitialized_flag=BOOST_ONCE_INITIAL_FLAG_VALUE;
+        static thread_detail::uintmax_atomic_t const being_initialized=uninitialized_flag+1;
+        thread_detail::uintmax_atomic_t const epoch=flag.epoch;
+        thread_detail::uintmax_atomic_t& this_thread_epoch=detail::get_once_per_thread_epoch();
 
         if(epoch<this_thread_epoch)
         {
diff --git a/src/pthread/once.cpp b/src/pthread/once.cpp
index a1d8a82d..54bf4c2d 100644
--- a/src/pthread/once.cpp
+++ b/src/pthread/once.cpp
@@ -14,7 +14,7 @@ namespace boost
 {
     namespace detail
     {
-        BOOST_THREAD_DECL boost::uintmax_t once_global_epoch=UINTMAX_C(~0);
+        BOOST_THREAD_DECL thread_detail::uintmax_atomic_t once_global_epoch=BOOST_THREAD_DETAIL_UINTMAX_ATOMIC_C(~0);
         BOOST_THREAD_DECL pthread_mutex_t once_epoch_mutex=PTHREAD_MUTEX_INITIALIZER;
         BOOST_THREAD_DECL pthread_cond_t once_epoch_cv = PTHREAD_COND_INITIALIZER;
 
@@ -55,17 +55,17 @@ namespace boost
 #endif
         }
 
-        boost::uintmax_t& get_once_per_thread_epoch()
+        thread_detail::uintmax_atomic_t& get_once_per_thread_epoch()
         {
             BOOST_VERIFY(!pthread_once(&epoch_tss_key_flag,create_epoch_tss_key));
             void* data=pthread_getspecific(epoch_tss_key);
             if(!data)
             {
-                data=malloc(sizeof(boost::uintmax_t));
+                data=malloc(sizeof(thread_detail::uintmax_atomic_t));
                 BOOST_VERIFY(!pthread_setspecific(epoch_tss_key,data));
-                *static_cast<boost::uintmax_t*>(data)=UINTMAX_C(~0);
+                *static_cast<thread_detail::uintmax_atomic_t*>(data)=BOOST_THREAD_DETAIL_UINTMAX_ATOMIC_C(~0);
             }
-            return *static_cast<boost::uintmax_t*>(data);
+            return *static_cast<thread_detail::uintmax_atomic_t*>(data);
         }
     }