[Boost-commit] svn:boost r84877 - in trunk/boost/asio/detail: . impl

Subject: [Boost-commit] svn:boost r84877 - in trunk/boost/asio/detail: . impl
From: chris_at_[hidden]
Date: 2013-06-22 08:47:44

Author: chris_kohlhoff
Date: 2013-06-22 08:47:44 EDT (Sat, 22 Jun 2013)
New Revision: 84877
URL: http://svn.boost.org/trac/boost/changeset/84877

Log:
Add mechanism for disabling automatic Winsock initialisation. Refs #3605

Text files modified: 
   trunk/boost/asio/detail/impl/winsock_init.ipp |    13 +++++++++++++                           
   trunk/boost/asio/detail/winsock_init.hpp      |    38 ++++++++++++++++++++++++++++++++++++++  
   2 files changed, 51 insertions(+), 0 deletions(-)

Modified: trunk/boost/asio/detail/impl/winsock_init.ipp
==============================================================================
--- trunk/boost/asio/detail/impl/winsock_init.ipp	Sat Jun 22 08:45:33 2013	(r84876)
+++ trunk/boost/asio/detail/impl/winsock_init.ipp	2013-06-22 08:47:44 EDT (Sat, 22 Jun 2013)	(r84877)
@@ -41,6 +41,14 @@
   }
 }
 
+void winsock_init_base::manual_startup(data& d)
+{
+  if (::InterlockedIncrement(&d.init_count_) == 1)
+  {
+    ::InterlockedExchange(&d.result_, 0);
+  }
+}
+
 void winsock_init_base::cleanup(data& d)
 {
   if (::InterlockedDecrement(&d.init_count_) == 0)
@@ -49,6 +57,11 @@
   }
 }
 
+void winsock_init_base::manual_cleanup(data& d)
+{
+  ::InterlockedDecrement(&d.init_count_);
+}
+
 void winsock_init_base::throw_on_error(data& d)
 {
   long result = ::InterlockedExchangeAdd(&d.result_, 0);

Modified: trunk/boost/asio/detail/winsock_init.hpp
==============================================================================
--- trunk/boost/asio/detail/winsock_init.hpp	Sat Jun 22 08:45:33 2013	(r84876)
+++ trunk/boost/asio/detail/winsock_init.hpp	2013-06-22 08:47:44 EDT (Sat, 22 Jun 2013)	(r84877)
@@ -39,8 +39,12 @@
   BOOST_ASIO_DECL static void startup(data& d,
       unsigned char major, unsigned char minor);
 
+  BOOST_ASIO_DECL static void manual_startup(data& d);
+
   BOOST_ASIO_DECL static void cleanup(data& d);
 
+  BOOST_ASIO_DECL static void manual_cleanup(data& d);
+
   BOOST_ASIO_DECL static void throw_on_error(data& d);
 };
 
@@ -66,7 +70,41 @@
     cleanup(data_);
   }
 
+  // This class may be used to indicate that user code will manage Winsock
+  // initialisation and cleanup. This may be required in the case of a DLL, for
+  // example, where it is not safe to initialise Winsock from global object
+  // constructors.
+  //
+  // To prevent asio from initialising Winsock, the object must be constructed
+  // before any Asio's own global objects. With MSVC, this may be accomplished
+  // by adding the following code to the DLL:
+  //
+  //   #pragma warning(push)
+  //   #pragma warning(disable:4073)
+  //   #pragma init_seg(lib)
+  //   boost::asio::detail::winsock_init<>::manual manual_winsock_init;
+  //   #pragma warning(pop)
+  class manual
+  {
+  public:
+    manual()
+    {
+      manual_startup(data_);
+    }
+
+    manual(const manual&)
+    {
+      manual_startup(data_);
+    }
+
+    ~manual()
+    {
+      manual_cleanup(data_);
+    }
+  };
+
 private:
+  friend class manual;
   static data data_;
 };