c++config (_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE, [...]): Add.

2010-08-12  Kostya Serebryany <kcc@google.com>
	    Paolo Carlini  <paolo.carlini@oracle.com>

	* include/bits/c++config (_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE,
	_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER): Add.
	* src/ios_init.cc (ios_base::Init::~Init): Decorate with the
	latter.
	* include/tr1_impl/boost_sp_counted_base.h: Likewise.
	* include/ext/rc_string_base.h: Likewise.
	* include/bits/locale_classes.h: Likewise.
	* include/bits/basic_string.h: Likewise.
	* include/bits/ios_base.h: Likewise.
	* testsuite/27_io/ios_base/cons/assign_neg.cc: Adjust dg-error
	line number.
	* testsuite/27_io/ios_base/cons/copy_neg.cc: Likewise.
	* testsuite/ext/profile/mutex_extensions.cc: Likewise.

Co-Authored-By: Paolo Carlini <paolo.carlini@oracle.com>

From-SVN: r163210
This commit is contained in:
Kostya Serebryany 2010-08-12 22:56:59 +00:00 committed by Paolo Carlini
parent 644fa7acbd
commit be335b18a9
11 changed files with 101 additions and 13 deletions

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@ -1,3 +1,20 @@
2010-08-12 Kostya Serebryany <kcc@google.com>
Paolo Carlini <paolo.carlini@oracle.com>
* include/bits/c++config (_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE,
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER): Add.
* src/ios_init.cc (ios_base::Init::~Init): Decorate with the
latter.
* include/tr1_impl/boost_sp_counted_base.h: Likewise.
* include/ext/rc_string_base.h: Likewise.
* include/bits/locale_classes.h: Likewise.
* include/bits/basic_string.h: Likewise.
* include/bits/ios_base.h: Likewise.
* testsuite/27_io/ios_base/cons/assign_neg.cc: Adjust dg-error
line number.
* testsuite/27_io/ios_base/cons/copy_neg.cc: Likewise.
* testsuite/ext/profile/mutex_extensions.cc: Likewise.
2010-08-11 Paolo Carlini <paolo.carlini@oracle.com>
* include/bits/hashtable.h (_Hashtable<>::erase(const key_type&)):

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@ -232,9 +232,16 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
if (__builtin_expect(this != &_S_empty_rep(), false))
#endif
if (__gnu_cxx::__exchange_and_add_dispatch(&this->_M_refcount,
-1) <= 0)
_M_destroy(__a);
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&this->_M_refcount)
if (__gnu_cxx::__exchange_and_add_dispatch(&this->_M_refcount,
-1) <= 0)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&this->_M_refcount)
_M_destroy(__a);
}
}
} // XXX MT
void

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@ -60,6 +60,35 @@
# define _GLIBCXX_DEPRECATED_ATTR
#endif
// Macros for race detectors.
// _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(A) and
// _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(A) should be used to explain
// atomic (lock-free) synchronization to race detectors:
// the race detector will infer a happens-before arc from the former to the
// latter when they share the same argument pointer.
//
// The most frequent use case for these macros (and the only case in the
// current implementation of the library) is atomic reference counting:
// void _M_remove_reference()
// {
// _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&this->_M_refcount)
// if (__gnu_cxx::__exchange_and_add_dispatch(&this->_M_refcount, -1) <= 0)
// {
// _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&this->_M_refcount)
// _M_destroy(__a);
// }
// }
// The annotations in this example tell the race detector that all memory
// accesses occurred when the refcount was positive do not race with
// memory accesses which occurred after the refcount became zero.
#ifndef _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE
# define _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(A)
#endif
#ifndef _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER
# define _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(A)
#endif
// Macros for activating various namespace association modes.
// _GLIBCXX_NAMESPACE_ASSOCIATION_DEBUG
// _GLIBCXX_NAMESPACE_ASSOCIATION_PARALLEL

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@ -474,7 +474,16 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
// 0 => OK to delete.
int
_M_remove_reference()
{ return __gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1); }
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount)
int __res = __gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1);
if (__res == 0)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount)
}
return __res;
}
};
_Callback_list* _M_callbacks;
@ -962,4 +971,3 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
_GLIBCXX_END_NAMESPACE
#endif /* _IOS_BASE_H */

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@ -402,8 +402,11 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
void
_M_remove_reference() const throw()
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount)
if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount)
__try
{ delete this; }
__catch(...)
@ -508,8 +511,11 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
void
_M_remove_reference() throw()
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount)
if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount)
__try
{ delete this; }
__catch(...)

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@ -199,9 +199,16 @@ _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
void
_M_dispose()
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_rep()->_M_info.
_M_refcount)
if (__exchange_and_add_dispatch(&_M_rep()->_M_info._M_refcount,
-1) <= 0)
_M_rep()->_M_destroy(_M_get_allocator());
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_rep()->_M_info.
_M_refcount)
_M_rep()->_M_destroy(_M_get_allocator());
}
} // XXX MT
bool

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@ -1,6 +1,6 @@
// <tr1_impl/boost_sp_counted_base.h> -*- C++ -*-
// Copyright (C) 2007, 2009 Free Software Foundation, Inc.
// Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
@ -139,8 +139,11 @@ _GLIBCXX_BEGIN_NAMESPACE_TR1
void
_M_release() // nothrow
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_use_count)
if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, -1) == 1)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_use_count)
_M_dispose();
// There must be a memory barrier between dispose() and destroy()
// to ensure that the effects of dispose() are observed in the
@ -152,9 +155,14 @@ _GLIBCXX_BEGIN_NAMESPACE_TR1
_GLIBCXX_WRITE_MEM_BARRIER;
}
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count)
if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count,
-1) == 1)
_M_destroy();
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count)
_M_destroy();
}
}
}
@ -165,8 +173,11 @@ _GLIBCXX_BEGIN_NAMESPACE_TR1
void
_M_weak_release() // nothrow
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count)
if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, -1) == 1)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count)
if (_Mutex_base<_Lp>::_S_need_barriers)
{
// See _M_release(),

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@ -1,7 +1,7 @@
// Iostreams base classes -*- C++ -*-
// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
// 2006, 2007, 2008, 2009
// 2006, 2007, 2008, 2009, 2010
// Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
@ -122,8 +122,11 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
ios_base::Init::~Init()
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_S_refcount)
if (__gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, -1) == 2)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_S_refcount)
// Catch any exceptions thrown by basic_ostream::flush()
__try
{

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@ -34,5 +34,5 @@ void test01()
}
// { dg-error "synthesized" "" { target *-*-* } 33 }
// { dg-error "within this context" "" { target *-*-* } 26 }
// { dg-error "is private" "" { target *-*-* } 779 }
// { dg-error "is private" "" { target *-*-* } 788 }
// { dg-error "operator=" "" { target *-*-* } 0 }

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@ -34,5 +34,5 @@ void test02()
}
// { dg-error "within this context" "" { target *-*-* } 26 }
// { dg-error "synthesized" "" { target *-*-* } 33 }
// { dg-error "is private" "" { target *-*-* } 776 }
// { dg-error "is private" "" { target *-*-* } 785 }
// { dg-error "copy constructor" "" { target *-*-* } 0 }

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@ -3,7 +3,7 @@
// -*- C++ -*-
// Copyright (C) 2006, 2007, 2009 Free Software Foundation, Inc.
// Copyright (C) 2006, 2007, 2009, 2010 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
@ -22,4 +22,4 @@
#include <vector>
// { dg-error "Cannot use -D_GLIBCXX_PROFILE with " "" { target *-*-* } 167 }
// { dg-error "Cannot use -D_GLIBCXX_PROFILE with " "" { target *-*-* } 196 }