From eea1e607177e339e05daa1a2ec969a9dd12f2497 Mon Sep 17 00:00:00 2001
From: Kimball Thurston <kdt3rd@gmail.com>
Date: Wed, 4 Apr 2018 00:35:17 +1200
Subject: [PATCH] switch IlmThread to use c++11 threads when enabled

---
 IlmBase/IlmThread/IlmThread.cpp      | 48 ++++++++++++++++++++++++----
 IlmBase/IlmThread/IlmThread.h        | 42 ++++++++++++++----------
 IlmBase/IlmThread/IlmThreadPosix.cpp |  2 ++
 IlmBase/IlmThread/IlmThreadWin32.cpp |  6 ++++
 4 files changed, 76 insertions(+), 22 deletions(-)

diff --git a/IlmBase/IlmThread/IlmThread.cpp b/IlmBase/IlmThread/IlmThread.cpp
index 5e9c38375f..6ad573a3fb 100644
--- a/IlmBase/IlmThread/IlmThread.cpp
+++ b/IlmBase/IlmThread/IlmThread.cpp
@@ -34,21 +34,56 @@
 
 //-----------------------------------------------------------------------------
 //
-//	class Thread -- dummy implementation for
-//	platforms that do not support threading
+//	class Thread -- this file contains two implementations of thread:
+//	- dummy implementation for platforms that do not support threading
+//	  when FORCE_CXX03 is on
+//	- c++11 and newer version
 //
 //-----------------------------------------------------------------------------
 
 #include "IlmBaseConfig.h"
-
-#if !defined (_WIN32) &&!(_WIN64) && !(HAVE_PTHREAD)
-
 #include "IlmThread.h"
 #include "Iex.h"
 
 ILMTHREAD_INTERNAL_NAMESPACE_SOURCE_ENTER
 
+#ifndef ILMBASE_FORCE_CXX03
+//-----------------------------------------------------------------------------
+// C++11 and newer implementation
+//-----------------------------------------------------------------------------
+bool
+supportsThreads ()
+{
+    return true;
+}
+
+Thread::Thread ()
+{
+    // empty
+}
+
 
+Thread::~Thread ()
+{
+    // hopefully the thread has basically exited and we are just
+    // cleaning up, because run is a virtual function, so the v-table
+    // has already been partly destroyed...
+    if ( _thread.joinable () )
+        _thread.join ();
+}
+
+
+void
+Thread::start ()
+{
+    _thread = std::thread (&Thread::run, this);
+}
+
+#else
+#   if !defined (_WIN32) &&!(_WIN64) && !(HAVE_PTHREAD)
+//-----------------------------------------------------------------------------
+// FORCE_CXX03 with no windows / pthread support
+//-----------------------------------------------------------------------------
 bool
 supportsThreads ()
 {
@@ -73,8 +108,9 @@ Thread::start ()
 {
     throw IEX_NAMESPACE::NoImplExc ("Threads not supported on this platform.");
 }
+#   endif
+#endif
 
 
 ILMTHREAD_INTERNAL_NAMESPACE_SOURCE_EXIT
 
-#endif
diff --git a/IlmBase/IlmThread/IlmThread.h b/IlmBase/IlmThread/IlmThread.h
index 1f6d9e68cd..249258e786 100644
--- a/IlmBase/IlmThread/IlmThread.h
+++ b/IlmBase/IlmThread/IlmThread.h
@@ -94,15 +94,19 @@
 #include "IlmThreadExport.h"
 #include "IlmThreadNamespace.h"
 
-#if defined _WIN32 || defined _WIN64
-    #ifdef NOMINMAX
-        #undef NOMINMAX
-    #endif
-    #define NOMINMAX
-    #include <windows.h>
-    #include <process.h>
-#elif HAVE_PTHREAD
-    #include <pthread.h>
+#ifdef ILMBASE_FORCE_CXX03
+#   if defined _WIN32 || defined _WIN64
+#       ifdef NOMINMAX
+#          undef NOMINMAX
+#       endif
+#       define NOMINMAX
+#       include <windows.h>
+#       include <process.h>
+#   elif HAVE_PTHREAD
+#      include <pthread.h>
+#   endif
+#else
+#   include <thread>
 #endif
 
 ILMTHREAD_INTERNAL_NAMESPACE_HEADER_ENTER
@@ -122,19 +126,25 @@ class ILMTHREAD_EXPORT Thread
     Thread ();
     virtual ~Thread ();
 
-    void		start ();
-    virtual void	run () = 0;
-    
+    void         start ();
+    virtual void run () = 0;
+
   private:
 
-    #if defined _WIN32 || defined _WIN64
+#ifdef ILMBASE_FORCE_CXX03
+#   if defined _WIN32 || defined _WIN64
 	HANDLE _thread;
-    #elif HAVE_PTHREAD
+#   elif HAVE_PTHREAD
 	pthread_t _thread;
-    #endif
-
+#   endif
     void operator = (const Thread& t);	// not implemented
     Thread (const Thread& t);		// not implemented
+#else
+    std::thread _thread;
+
+    Thread &operator= (const Thread& t) = delete;
+    Thread (const Thread& t) = delete;
+#endif
 };
 
 
diff --git a/IlmBase/IlmThread/IlmThreadPosix.cpp b/IlmBase/IlmThread/IlmThreadPosix.cpp
index c487e39fa9..4aee3f3ca2 100644
--- a/IlmBase/IlmThread/IlmThreadPosix.cpp
+++ b/IlmBase/IlmThread/IlmThreadPosix.cpp
@@ -42,6 +42,7 @@
 #include "IlmBaseConfig.h"
 
 #if HAVE_PTHREAD
+#ifdef ILMBASE_FORCE_CXX03
 
 #include "IlmThread.h"
 #include "Iex.h"
@@ -96,3 +97,4 @@ Thread::start ()
 ILMTHREAD_INTERNAL_NAMESPACE_SOURCE_EXIT
 
 #endif
+#endif
diff --git a/IlmBase/IlmThread/IlmThreadWin32.cpp b/IlmBase/IlmThread/IlmThreadWin32.cpp
index c563091b71..43ec23f6e6 100644
--- a/IlmBase/IlmThread/IlmThreadWin32.cpp
+++ b/IlmBase/IlmThread/IlmThreadWin32.cpp
@@ -39,6 +39,10 @@
 //-----------------------------------------------------------------------------
 
 
+#include "IlmBaseConfig.h"
+
+#ifdef ILMBASE_FORCE_CXX03
+
 #include "IlmThread.h"
 #include "Iex.h"
 #include <iostream>
@@ -93,3 +97,5 @@ Thread::start ()
 
 
 ILMTHREAD_INTERNAL_NAMESPACE_SOURCE_EXIT
+
+#endif