diff mbox

PR 53889: Add __gthread_recursive_mutex_destroy

Message ID CAH6eHdSXn1saDGoYTPw4PaqGhHv31fPm2TuoV1vNw6c=mcrZRg@mail.gmail.com
State New
Headers show

Commit Message

Jonathan Wakely Oct. 2, 2012, 12:46 a.m. UTC 
On 1 October 2012 20:22, Ian Lance Taylor wrote:
> On Sun, Sep 30, 2012 at 11:41 AM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>> There is no __gthread_recursive_mutex_destroy function in the gthreads API.
>>
>> Trying to use __gthread_mutex_destroy fails to compile on platforms
>> where the mutex
>> types are different. To avoid resource leaks libstdc++ needs to hack
>> around the missing function with overloaded functions and SFINAE
>> tricks to detect how a recursive mutex can be destroyed.
>>
>> This patch extends the gthreads API to include
>> __gthread_recursive_mutex_destroy, defining it for each gthread model,
>> and removing the hacks from libstdc++.
>
>> +    return rtems_gxx_mutex_destroy( __mutex );
>
> Space before '(', not space after.

Oops, yes.

> Doing anything else here is going to be painful, but this assumes that
> RTEMS uses the same representation for non-recursive and recursive
> mutexes.  That is currently true, but it deserves a comment.

Good point ... I have a vague recollection that I looked into it and
decided they were the same, but I wrote this patch back in July and
don't remember the details. If anyone knows better please let me know.
The attached revised patch adds a comment.

>> --- a/libgcc/config/i386/gthr-win32.h
>> +++ b/libgcc/config/i386/gthr-win32.h
>> +static inline void
>> +__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *mutex)
>> +{
>> +  __gthread_mutex_t __mutex2;
>> +  __mutex2.sema = mutex->sema;
>> +  __gthr_win32_mutex_destroy (&__mutex2);
>> +}
>
> I think it would be better to put this in
> libgcc/config/i386/gthr-win32.c, like the other functions.  Then you
> can just call CloseHandle.

Done. I've also made __gthread_recursive_mutex_destroy return int,
unlike the Win32 __ghtread_mutex_destroy (see PR 53888 for that)


>> --- a/libgcc/config/mips/gthr-mipssde.h
>> +++ b/libgcc/config/mips/gthr-mipssde.h
>>
>> +static inline int
>> +__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex)
>> +{
>> +  return __gthread_mutex_destroy(__mutex);
>> +}
>
> Will this even compile?  It doesn't look like it.

Nope, you're right.

I've replaced it with this, which is all __ghtread_mutex_destroy does anyway:

static inline int
__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t
                                   * UNUSED(__mutex))
{
  return 0;
}

Is that indentation right?  (the asterisk is in the same column as the
parameter type in a fixed-width font.)

Thanks for the careful review.

The ChangeLog entry is the same, I haven't rested this because the
changes since the first patch are only to targets I don't have access
to.

libgcc:

        PR other/53889
        * gthr.h (__gthread_recursive_mutex_destroy): Document new required
        function.
        * gthr-posix.h (__gthread_recursive_mutex_destroy): Define.
        * gthr-single.h (__gthread_recursive_mutex_destroy): Likewise.
        * config/gthr-rtems.h (__gthread_recursive_mutex_destroy): Likewise.
        * config/gthr-vxworks.h (__gthread_recursive_mutex_destroy): Likewise.
        * config/i386/gthr-win32.h (__gthread_recursive_mutex_destroy):
        Likewise.
        * config/mips/gthr-mipssde.h (__gthread_recursive_mutex_destroy):
        Likewise.
        * config/pa/gthr-dce.h (__gthread_recursive_mutex_destroy): Likewise.
        * config/s390/gthr-tpf.h (__gthread_recursive_mutex_destroy): Likewise.

libstdc++-v3:

        PR other/53889
        * include/std/mutex (__recursive_mutex_base::~__recursive_mutex_base):
        Use __gthread_recursive_mutex_destroy.
        (__recursive_mutex_base::_S_destroy): Remove.
        (__recursive_mutex_base::_S_destroy_win32): Likewise.
        * include/ext/concurrence.h (__recursive_mutex::~__recursive_mutex):
        Use __gthread_recursive_mutex_destroy.
        (__recursive_mutex::_S_destroy): Remove.
        (__recursive_mutex::_S_destroy_win32): Likewise.
commit 7877201b61694279811c0276c92d85aaec2b30a2
Author: Jonathan Wakely <jwakely.gcc@gmail.com>
Date:   Tue Oct 2 01:40:46 2012 +0100

    libgcc:
    
    	PR other/53889
    	* gthr.h (__gthread_recursive_mutex_destroy): Document new required
    	function.
    	* gthr-posix.h (__gthread_recursive_mutex_destroy): Define.
    	* gthr-single.h (__gthread_recursive_mutex_destroy): Likewise.
    	* config/gthr-rtems.h (__gthread_recursive_mutex_destroy): Likewise.
    	* config/gthr-vxworks.h (__gthread_recursive_mutex_destroy): Likewise.
    	* config/i386/gthr-win32.h (__gthread_recursive_mutex_destroy):
    	Likewise.
    	* config/mips/gthr-mipssde.h (__gthread_recursive_mutex_destroy):
    	Likewise.
    	* config/pa/gthr-dce.h (__gthread_recursive_mutex_destroy): Likewise.
    	* config/s390/gthr-tpf.h (__gthread_recursive_mutex_destroy): Likewise.
    
    libstdc++-v3:
    
    	PR other/53889
    	* include/std/mutex (__recursive_mutex_base::~__recursive_mutex_base):
    	Use __gthread_recursive_mutex_destroy.
    	(__recursive_mutex_base::_S_destroy): Remove.
    	(__recursive_mutex_base::_S_destroy_win32): Likewise.
    	* include/ext/concurrence.h (__recursive_mutex::~__recursive_mutex):
    	Use __gthread_recursive_mutex_destroy.
    	(__recursive_mutex::_S_destroy): Remove.
    	(__recursive_mutex::_S_destroy_win32): Likewise.

Comments

Ian Lance Taylor Oct. 2, 2012, 6:02 a.m. UTC | #1 
On Mon, Oct 1, 2012 at 5:46 PM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>
> static inline int
> __gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t
>                                    * UNUSED(__mutex))
> {
>   return 0;
> }
>
> Is that indentation right?  (the asterisk is in the same column as the
> parameter type in a fixed-width font.)

When I see a single parameter that pushes past 80 columns, I normally
start a new line after the left parenthesis and indent the next line 4
spaces.  E.g.:

static inline int
__gthread_recursive_mutex_destroy (
    __gthread_recursive_mutex_t * UNUSED(__mutex))

But I don't think there is any solid standard for this.

>         PR other/53889
>         * gthr.h (__gthread_recursive_mutex_destroy): Document new required
>         function.
>         * gthr-posix.h (__gthread_recursive_mutex_destroy): Define.
>         * gthr-single.h (__gthread_recursive_mutex_destroy): Likewise.
>         * config/gthr-rtems.h (__gthread_recursive_mutex_destroy): Likewise.
>         * config/gthr-vxworks.h (__gthread_recursive_mutex_destroy): Likewise.
>         * config/i386/gthr-win32.h (__gthread_recursive_mutex_destroy):
>         Likewise.
>         * config/mips/gthr-mipssde.h (__gthread_recursive_mutex_destroy):
>         Likewise.
>         * config/pa/gthr-dce.h (__gthread_recursive_mutex_destroy): Likewise.
>         * config/s390/gthr-tpf.h (__gthread_recursive_mutex_destroy): Likewise.

The libgcc part of this is OK.

Thanks.

Ian
Jakub Jelinek Oct. 2, 2012, 8:05 a.m. UTC | #2 
On Mon, Oct 01, 2012 at 11:02:27PM -0700, Ian Lance Taylor wrote:
> On Mon, Oct 1, 2012 at 5:46 PM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> >
> > static inline int
> > __gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t
> >                                    * UNUSED(__mutex))
> > {
> >   return 0;
> > }
> >
> > Is that indentation right?  (the asterisk is in the same column as the
> > parameter type in a fixed-width font.)
> 
> When I see a single parameter that pushes past 80 columns, I normally
> start a new line after the left parenthesis and indent the next line 4
> spaces.  E.g.:
> 
> static inline int
> __gthread_recursive_mutex_destroy (
>     __gthread_recursive_mutex_t * UNUSED(__mutex))
> 
> But I don't think there is any solid standard for this.

I believe the GNU coding standard way (as shown e.g. by what indent does by
default) is to split the single argument onto multiple lines if that still
fits (i.e.
static inline int
__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t
				   * UNUSED(__mutex))
{
  return 0;
}
should be fine), and if even that wouldn't fit, then place ( on the
following line indented by two spaces:
int
foo123456789012345678901234567890123456789012345678901234567890123456789012
  (int x, int y)
{
  return x + y;
}

I have never seen ( at the end of a line in GNU code and find it ugly, but
sure that is a bikeshed thing.

	Jakub
Jonathan Wakely Oct. 2, 2012, 8:24 p.m. UTC | #3 
On 2 October 2012 07:02, Ian Lance Taylor wrote:
>
> The libgcc part of this is OK.

Thanks, I've committed it and closed the PR.
diff mbox

Patch

diff --git a/libgcc/config/gthr-rtems.h b/libgcc/config/gthr-rtems.h
index c5bd522..3bfa67b 100644
--- a/libgcc/config/gthr-rtems.h
+++ b/libgcc/config/gthr-rtems.h
@@ -1,8 +1,7 @@ 
 /* RTEMS threads compatibility routines for libgcc2 and libobjc.
    by: Rosimildo da Silva( rdasilva@connecttel.com ) */
 /* Compile this one with gcc.  */
-/* Copyright (C) 1997, 1999, 2000, 2002, 2003, 2005, 2008, 2009
-   Free Software Foundation, Inc.
+/* Copyright (C) 1997-2012 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -150,6 +149,14 @@  __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex)
     return rtems_gxx_recursive_mutex_unlock( __mutex );
 }
 
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex)
+{
+  /* This requires that recursive and non-recursive mutexes have the same
+     representation.  */
+    return rtems_gxx_mutex_destroy (__mutex );
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libgcc/config/gthr-vxworks.h b/libgcc/config/gthr-vxworks.h
index 63116c4..b48c5ac 100644
--- a/libgcc/config/gthr-vxworks.h
+++ b/libgcc/config/gthr-vxworks.h
@@ -1,7 +1,6 @@ 
 /* Threads compatibility routines for libgcc2 and libobjc for VxWorks.  */
 /* Compile this one with gcc.  */
-/* Copyright (C) 1997, 1999, 2000, 2008, 2009, 2011
-   Free Software Foundation, Inc.
+/* Copyright (C) 1997-2012 Free Software Foundation, Inc.
    Contributed by Mike Stump <mrs@wrs.com>.
 
 This file is part of GCC.
@@ -111,6 +110,12 @@  __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)
   return __gthread_mutex_unlock (mutex);
 }
 
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex)
+{
+  return __gthread_mutex_destroy (__mutex);
+}
+
 /* pthread_once is complicated enough that it's implemented
    out-of-line.  See config/vxlib.c.  */
 
diff --git a/libgcc/config/i386/gthr-win32.c b/libgcc/config/i386/gthr-win32.c
index ab1b69f..fcb15df 100644
--- a/libgcc/config/i386/gthr-win32.c
+++ b/libgcc/config/i386/gthr-win32.c
@@ -1,8 +1,7 @@ 
 /* Implementation of W32-specific threads compatibility routines for
    libgcc2.  */
 
-/* Copyright (C) 1999, 2000, 2002, 2004, 2008, 2009, 2011
-   Free Software Foundation, Inc.
+/* Copyright (C) 1999-2012 Free Software Foundation, Inc.
    Contributed by Mumit Khan <khan@xraylith.wisc.edu>.
    Modified and moved to separate file by Danny Smith
    <dannysmith@users.sourceforge.net>.
@@ -259,3 +258,10 @@  __gthr_win32_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)
 
   return 0;
 }
+
+int
+__gthr_win32_recursive_mutex_destroy (__gthread_recursive_mutex_t *mutex)
+{
+  CloseHandle ((HANDLE) mutex->sema);
+  return 0;
+}
diff --git a/libgcc/config/i386/gthr-win32.h b/libgcc/config/i386/gthr-win32.h
index 53f8396..9656148 100644
--- a/libgcc/config/i386/gthr-win32.h
+++ b/libgcc/config/i386/gthr-win32.h
@@ -1,8 +1,7 @@ 
 /* Threads compatibility routines for libgcc2 and libobjc.  */
 /* Compile this one with gcc.  */
 
-/* Copyright (C) 1999, 2000, 2002, 2003, 2004, 2005, 2008, 2009
-   Free Software Foundation, Inc.
+/* Copyright (C) 1999-2012 Free Software Foundation, Inc.
    Contributed by Mumit Khan <khan@xraylith.wisc.edu>.
 
 This file is part of GCC.
@@ -430,6 +429,8 @@  extern int
   __gthr_win32_recursive_mutex_trylock (__gthread_recursive_mutex_t *);
 extern int __gthr_win32_recursive_mutex_unlock (__gthread_recursive_mutex_t *);
 extern void __gthr_win32_mutex_destroy (__gthread_mutex_t *);
+extern int
+  __gthr_win32_recursive_mutex_destroy (__gthread_recursive_mutex_t *);
 
 static inline int
 __gthread_once (__gthread_once_t *__once, void (*__func) (void))
@@ -536,6 +537,12 @@  __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex)
     return 0;
 }
 
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *mutex)
+{
+  return __gthr_win32_recursive_mutex_destroy (__mutex);
+}
+
 #else /* ! __GTHREAD_HIDE_WIN32API */
 
 #include <windows.h>
@@ -761,6 +768,13 @@  __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex)
   return 0;
 }
 
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *mutex)
+{
+  CloseHandle ((HANDLE) mutex->sema);
+  return 0;
+}
+
 #endif /*  __GTHREAD_HIDE_WIN32API */
 
 #ifdef __cplusplus
diff --git a/libgcc/config/mips/gthr-mipssde.h b/libgcc/config/mips/gthr-mipssde.h
index 34f9b6c..2ce2258 100644
--- a/libgcc/config/mips/gthr-mipssde.h
+++ b/libgcc/config/mips/gthr-mipssde.h
@@ -1,6 +1,6 @@ 
 /* MIPS SDE threads compatibility routines for libgcc2 and libobjc.  */
 /* Compile this one with gcc.  */
-/* Copyright (C) 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+/* Copyright (C) 2006-2012 Free Software Foundation, Inc.
    Contributed by Nigel Stephens <nigel@mips.com>
 
 This file is part of GCC.
@@ -223,6 +223,13 @@  __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex)
   return 0;
 }
 
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t
+                                   * UNUSED(__mutex))
+{
+  return 0;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libgcc/config/pa/gthr-dce.h b/libgcc/config/pa/gthr-dce.h
index d32155a..3ba43a1 100644
--- a/libgcc/config/pa/gthr-dce.h
+++ b/libgcc/config/pa/gthr-dce.h
@@ -1,7 +1,6 @@ 
 /* Threads compatibility routines for libgcc2 and libobjc.  */
 /* Compile this one with gcc.  */
-/* Copyright (C) 1997, 1999, 2000, 2001, 2004, 2005, 2008, 2009
-   Free Software Foundation, Inc.
+/* Copyright (C) 1997-2012 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -557,6 +556,12 @@  __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex)
   return __gthread_mutex_unlock (__mutex);
 }
 
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex)
+{
+  return __gthread_mutex_destroy (__mutex);
+}
+
 #endif /* _LIBOBJC */
 
 #endif
diff --git a/libgcc/config/s390/gthr-tpf.h b/libgcc/config/s390/gthr-tpf.h
index fb23e91..49bce4c 100644
--- a/libgcc/config/s390/gthr-tpf.h
+++ b/libgcc/config/s390/gthr-tpf.h
@@ -1,6 +1,6 @@ 
 /* Threads compatibility routines for libgcc2 and libobjc.
    Compile this one with gcc.
-   Copyright (C) 2004, 2005, 2008, 2009 Free Software Foundation, Inc.
+   Copyright (C) 2004-2012 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -225,5 +225,10 @@  __gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *__mutex)
   return 0;
 }
 
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex)
+{
+  return __gthread_mutex_destroy (__mutex);
+}
 
 #endif /* ! GCC_GTHR_TPF_H */
diff --git a/libgcc/gthr-posix.h b/libgcc/gthr-posix.h
index cc4e518..1e7ddfe 100644
--- a/libgcc/gthr-posix.h
+++ b/libgcc/gthr-posix.h
@@ -832,6 +832,12 @@  __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex)
   return __gthread_mutex_unlock (__mutex);
 }
 
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex)
+{
+  return __gthread_mutex_destroy (__mutex);
+}
+
 #ifdef _GTHREAD_USE_COND_INIT_FUNC
 static inline void
 __gthread_cond_init_function (__gthread_cond_t *__cond)
diff --git a/libgcc/gthr-single.h b/libgcc/gthr-single.h
index 4e39679..717e6cb 100644
--- a/libgcc/gthr-single.h
+++ b/libgcc/gthr-single.h
@@ -1,7 +1,6 @@ 
 /* Threads compatibility routines for libgcc2 and libobjc.  */
 /* Compile this one with gcc.  */
-/* Copyright (C) 1997, 1999, 2000, 2004, 2008, 2009
-   Free Software Foundation, Inc.
+/* Copyright (C) 1997-2012 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -286,6 +285,12 @@  __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex)
   return __gthread_mutex_unlock (__mutex);
 }
 
+static inline int
+__gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex)
+{
+  return __gthread_mutex_destroy (__mutex);
+}
+
 #endif /* _LIBOBJC */
 
 #undef UNUSED
diff --git a/libgcc/gthr.h b/libgcc/gthr.h
index 813abe1..9f2b53d 100644
--- a/libgcc/gthr.h
+++ b/libgcc/gthr.h
@@ -1,7 +1,6 @@ 
 /* Threads compatibility routines for libgcc2.  */
 /* Compile this one with gcc.  */
-/* Copyright (C) 1997, 1998, 2004, 2008, 2009, 2011
-   Free Software Foundation, Inc.
+/* Copyright (C) 1997-2012 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -73,6 +72,7 @@  see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      int __gthread_setspecific (__gthread_key_t key, const void *ptr)
 
      int __gthread_mutex_destroy (__gthread_mutex_t *mutex);
+     int __gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *mutex);
 
      int __gthread_mutex_lock (__gthread_mutex_t *mutex);
      int __gthread_mutex_trylock (__gthread_mutex_t *mutex);
diff --git a/libstdc++-v3/include/ext/concurrence.h b/libstdc++-v3/include/ext/concurrence.h
index ad02839..68c679c 100644
--- a/libstdc++-v3/include/ext/concurrence.h
+++ b/libstdc++-v3/include/ext/concurrence.h
@@ -219,7 +219,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     ~__recursive_mutex()
     {
       if (__gthread_active_p())
-	_S_destroy(&_M_mutex);
+	__gthread_recursive_mutex_destroy(&_M_mutex);
     }
 #endif
 
@@ -247,43 +247,6 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
     __gthread_recursive_mutex_t* gthread_recursive_mutex(void)
     { return &_M_mutex; }
-
-#if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
-    // FIXME: gthreads doesn't define __gthread_recursive_mutex_destroy
-    // so we need to obtain a __gthread_mutex_t to destroy
-  private:
-    template<typename _Mx, typename _Rm>
-      static void
-      _S_destroy_win32(_Mx* __mx, _Rm const* __rmx)
-      {
-        __mx->counter = __rmx->counter;
-        __mx->sema = __rmx->sema;
-        __gthread_mutex_destroy(__mx);
-      }
-
-    // matches a gthr-win32.h recursive mutex
-    template<typename _Rm>
-      static typename __enable_if<(bool)sizeof(&_Rm::sema), void>::__type
-      _S_destroy(_Rm* __mx)
-      {
-        __gthread_mutex_t __tmp;
-        _S_destroy_win32(&__tmp, __mx);
-      }
-
-    // matches a recursive mutex with a member 'actual'
-    template<typename _Rm>
-      static typename __enable_if<(bool)sizeof(&_Rm::actual), void>::__type
-      _S_destroy(_Rm* __mx)
-      { __gthread_mutex_destroy(&__mx->actual); }
-
-    // matches when there's only one mutex type
-    template<typename _Rm>
-      static typename
-      __enable_if<std::__are_same<_Rm, __gthread_mutex_t>::__value,
-        void>::__type
-      _S_destroy(_Rm* __mx)
-      { __gthread_mutex_destroy(__mx); }
-#endif
   };
 
   /// Scoped lock idiom.
diff --git a/libstdc++-v3/include/std/mutex b/libstdc++-v3/include/std/mutex
index 34d64c5..b28a53e 100644
--- a/libstdc++-v3/include/std/mutex
+++ b/libstdc++-v3/include/std/mutex
@@ -101,42 +101,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
     ~__recursive_mutex_base()
-    { _S_destroy(&_M_mutex); }
-
-  private:
-    // FIXME: gthreads doesn't define __gthread_recursive_mutex_destroy
-    // so we need to obtain a __gthread_mutex_t to destroy
-
-    // matches when there's only one mutex type
-    template<typename _Rm>
-      static
-      typename enable_if<is_same<_Rm, __gthread_mutex_t>::value, void>::type
-      _S_destroy(_Rm* __mx)
-      { __gthread_mutex_destroy(__mx); }
-
-    // matches a recursive mutex with a member 'actual'
-    template<typename _Rm>
-      static typename enable_if<(bool)sizeof(&_Rm::actual), void>::type
-      _S_destroy(_Rm* __mx)
-      { __gthread_mutex_destroy(&__mx->actual); }
-
-    // matches a gthr-win32.h recursive mutex
-    template<typename _Rm>
-      static typename enable_if<(bool)sizeof(&_Rm::sema), void>::type
-      _S_destroy(_Rm* __mx)
-      {
-        __gthread_mutex_t __tmp;
-        _S_destroy_win32(&__tmp, __mx);
-      }
-
-    template<typename _Mx, typename _Rm>
-      static void
-      _S_destroy_win32(_Mx* __mx, _Rm const* __rmx)
-      {
-        __mx->counter = __rmx->counter;
-        __mx->sema = __rmx->sema;
-        __gthread_mutex_destroy(__mx);
-      }
+    { __gthread_recursive_mutex_destroy(&_M_mutex); }
 #endif
   };