Changed call_once to header-only template that takes arbitrary function objects; this changes parameter order

[SVN r39701]

src/once.cpp

@@ -6,6 +6,7 @@
 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
 #include <boost/thread/detail/config.hpp>
+#ifdef BOOST_HAS_MPTASKS
 
 #include <boost/detail/workaround.hpp>
 
@@ -13,59 +14,8 @@
 #include <cstdio>
 #include <cassert>
 
+#include <Multiprocessing.h>
 
-#if defined(BOOST_HAS_WINTHREADS)
-#   if BOOST_WORKAROUND(__BORLANDC__,<= 0x551)
-      using std::size_t;
-#   endif
-#   include <windows.h>
-#   if defined(BOOST_NO_STRINGSTREAM)
-#       include <strstream>
-
-class unfreezer
-{
-public:
-    unfreezer(std::ostrstream& s) : m_stream(s) {}
-    ~unfreezer() { m_stream.freeze(false); }
-private:
-    std::ostrstream& m_stream;
-};
-
-#   else
-#       include <sstream>
-#   endif
-#elif defined(BOOST_HAS_MPTASKS)
-#   include <Multiprocessing.h>
-#endif
-
-#ifdef BOOST_NO_STDC_NAMESPACE
-namespace std { using ::sprintf; }
-#endif
-
-#if defined(BOOST_HAS_PTHREADS)
-namespace {
-pthread_key_t key;
-pthread_once_t once = PTHREAD_ONCE_INIT;
-
-typedef void (*once_callback)();
-}
-
-extern "C" {
-
-    static void key_init()
-    {
-        pthread_key_create(&key, 0);
-    }
-
-    static void do_once()
-    {
-        once_callback* cb = reinterpret_cast<once_callback*>(
-            pthread_getspecific(key));
-        (**cb)();
-    }
-
-}
-#elif defined(BOOST_HAS_MPTASKS)
 namespace {
 void *remote_call_proxy(void *pData)
 {
@@ -82,125 +32,10 @@ void *remote_call_proxy(void *pData)
 }
 }
 
-#elif defined(BOOST_HAS_WINTHREADS)
-namespace {
-// The signature for InterlockedCompareExchange has changed with the
-// addition of Win64 support. I can't determine any (consistent and
-// portable) way of using conditional compilation to detect this, so
-// we use these type wrappers.  Unfortunately, the various vendors
-// use different calling conventions and other signature anamolies,
-// and thus have unique types as well.  This is known to work on VC6,
-// VC7, Borland 5.5.2 and gcc 3.2.  Are there other signatures for
-// other platforms?
-inline LONG ice_wrapper(LONG (__stdcall *ice)(LONG*, LONG, LONG),
-    volatile LONG* dest, LONG exch, LONG cmp)
-{
-    return (*ice)(const_cast<LONG*>(dest), exch, cmp);
-}
-
-inline LONG ice_wrapper(LONG (__stdcall *ice)(volatile LONG*, LONG, LONG),
-    volatile LONG* dest, LONG exch, LONG cmp)
-{
-    return (*ice)(dest, exch, cmp);
-}
-
-inline LONG ice_wrapper(LPVOID (__stdcall *ice)(LPVOID*, LPVOID, LPVOID),
-    volatile LONG* dest, LONG exch, LONG cmp)
-{
-    return (LONG)(*ice)((LPVOID*)dest, (LPVOID)exch, (LPVOID)cmp);
-}
-
-// The friendly form of InterlockedCompareExchange that defers
-// according to the above function type wrappers.
-inline LONG compare_exchange(volatile LPLONG dest, LONG exch, LONG cmp)
-{
-#ifdef _WIN64
-    // Original patch from Anthony Williams.
-    // I (Roland Schwarz) am trying this for RC_1_34_0, since x64 regressions are
-    // currently not run on x64 platforms for HEAD
-    return InterlockedCompareExchange(dest, exch,cmp);
-#else    
-    return ice_wrapper(&InterlockedCompareExchange, dest, exch, cmp);
-#endif
-}
-}
-#endif
-
 namespace boost {
 
-void call_once(void (*func)(), once_flag& flag)
+    void call_once(once_flag& flag, void (*func)())
 {
-#if defined(BOOST_HAS_WINTHREADS)
-    if (compare_exchange(&flag, 1, 1) == 0)
-    {
-#if defined(BOOST_NO_STRINGSTREAM)
-        std::ostrstream strm;
-        strm << "2AC1A572DB6944B0A65C38C4140AF2F4" 
-             << std::hex
-             << GetCurrentProcessId() 
-             << &flag 
-             << std::ends;
-        unfreezer unfreeze(strm);
-#   if defined (BOOST_NO_ANSI_APIS)
-        int const num_wide_chars = ::MultiByteToWideChar(CP_ACP, 0, strm.str(), -1, 0, 0);
-        LPWSTR const wide_name = (LPWSTR)_alloca( (num_wide_chars+1) * 2 );
-        int const res=::MultiByteToWideChar(CP_ACP, 0, name, -1, wide_name, num_wide_chars);
-        if(!res)
-            throw boost::thread_resource_error();
-        HANDLE mutex = CreateMutexW(NULL, FALSE, wide_name);
-#   else
-        HANDLE mutex = CreateMutexA(NULL, FALSE, strm.str());
-#   endif
-#else
-#   if defined (BOOST_NO_ANSI_APIS)
-        std::wostringstream strm;
-        strm << L"2AC1A572DB6944B0A65C38C4140AF2F4" 
-             << std::hex
-             << GetCurrentProcessId() 
-             << &flag;
-        HANDLE mutex = CreateMutexW(NULL, FALSE, strm.str().c_str());
-#   else
-        std::ostringstream strm;
-        strm << "2AC1A572DB6944B0A65C38C4140AF2F4" 
-             << std::hex
-             << GetCurrentProcessId() 
-             << &flag;
-        HANDLE mutex = CreateMutexA(NULL, FALSE, strm.str().c_str());
-#   endif
-#endif
-        assert(mutex != NULL);
-
-        int res = 0;
-        res = WaitForSingleObject(mutex, INFINITE);
-        assert(res == WAIT_OBJECT_0);
-
-        if (compare_exchange(&flag, 1, 1) == 0)
-        {
-            try
-            {
-                func();
-            }
-            catch (...)
-            {
-                res = ReleaseMutex(mutex);
-                assert(res);
-                res = CloseHandle(mutex);
-                assert(res);
-                throw;
-            }
-            InterlockedExchange(&flag, 1);
-        }
-
-        res = ReleaseMutex(mutex);
-        assert(res);
-        res = CloseHandle(mutex);
-        assert(res);
-    }
-#elif defined(BOOST_HAS_PTHREADS)
-    pthread_once(&once, &key_init);
-    pthread_setspecific(key, &func);
-    pthread_once(&flag, do_once);
-#elif defined(BOOST_HAS_MPTASKS)
     if(flag == false)
     {
         // all we do here is make a remote call to blue, as blue is not
@@ -209,10 +44,7 @@ void call_once(void (*func)(), once_flag& flag)
         MPRemoteCall(remote_call_proxy, &sData, kMPOwningProcessRemoteContext);
         assert(flag == true);
     }
+}
+
+}
 #endif
-}
-
-}
-
-// Change Log:
-//   1 Aug 01  WEKEMPF Initial version.