OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
181,652 Commits 63 Branches 184 Tags 3.1 GiB
e8f83fa4fc
Commit Graph

23 Commits

Author SHA1 Message Date
Jonathan Wakely
e6923541fa libstdc++: Use __libc_single_threaded to optimise atomics [PR 96817] 
Glibc 2.32 adds a global variable that says whether the process is
single-threaded. We can use this to decide whether to elide atomic
operations, as a more precise and reliable indicator than
__gthread_active_p.

This means that guard variables for statics and reference counting in
shared_ptr can use less expensive, non-atomic ops even in processes that
are linked to libpthread, as long as no threads have been created yet.
It also means that we switch to using atomics if libpthread gets loaded
later via dlopen (this still isn't supported in general, for other
reasons).

We can't use __libc_single_threaded to replace __gthread_active_p
everywhere. If we replaced the uses of __gthread_active_p in std::mutex
then we would elide the pthread_mutex_lock in the code below, but not
the pthread_mutex_unlock:

  std::mutex m;
  m.lock();            // pthread_mutex_lock
  std::thread t([]{}); // __libc_single_threaded = false
  t.join();
  m.unlock();          // pthread_mutex_unlock

We need the lock and unlock to use the same "is threading enabled"
predicate, and similarly for init/destroy pairs for mutexes and
condition variables, so that we don't try to release resources that were
never acquired.

There are other places that could use __libc_single_threaded, such as
_Sp_locker in src/c++11/shared_ptr.cc and locale init functions, but
they can be changed later.

libstdc++-v3/ChangeLog:

	PR libstdc++/96817
	* include/ext/atomicity.h (__gnu_cxx::__is_single_threaded()):
	New function wrapping __libc_single_threaded if available.
	(__exchange_and_add_dispatch, __atomic_add_dispatch): Use it.
	* libsupc++/guard.cc (__cxa_guard_acquire, __cxa_guard_abort)
	(__cxa_guard_release): Likewise.
	* testsuite/18_support/96817.cc: New test.
 2020-09-26 20:32:36 +01:00
Jakub Jelinek
8d9254fc8a Update copyright years. 
From-SVN: r279813
 2020-01-01 12:51:42 +01:00
Jonathan Wakely
a10b664eb7 Fix recent regression in __atomic_add_dispatch 
* include/ext/atomicity.h (__exchange_and_add, __atomic_add): Replace
	throw() with _GLIBCXX_NOTHROW.
	(__atomic_add_dispatch): Return after performing atomic increment.

From-SVN: r273167
 2019-07-06 22:16:38 +01:00
Jonathan Wakely
0dc7adb037 Fix ODR violations in code using <ext/atomicity.h> 
Because the inline versions of __exchange_and_add and __atomic_add are
also marked static, they cannot be used from templates or other inline
functions without ODR violations. This change gives them external
linkage, but adds the always_inline attribute.

    	* include/ext/atomicity.h [_GLIBCXX_ATOMIC_BUILTINS] (__atomic_add)
    	(__exchange_and_add): Replace static specifier with always_inline
    	attribute.
    	(__exchange_and_add_single, __atomic_add_single): Likewise.
    	(__exchange_and_add_dispatch, __atomic_add_dispatch): Likewise. Also
    	combine !__gthread_active_p() and !__GTHREADS branches.

From-SVN: r273144
 2019-07-05 17:10:47 +01:00
Jakub Jelinek
a554497024 Update copyright years. 
From-SVN: r267494
 2019-01-01 13:31:55 +01:00
Jakub Jelinek
85ec4feb11 Update copyright years. 
From-SVN: r256169
 2018-01-03 11:03:58 +01:00
Jakub Jelinek
cbe34bb5ed Update copyright years. 
From-SVN: r243994
 2017-01-01 13:07:43 +01:00
Jakub Jelinek
818ab71a41 Update copyright years. 
From-SVN: r232055
 2016-01-04 15:30:50 +01:00
Ramana Radhakrishnan
57e6d9be77 Use atomics in guard.cc. 
This provides proper definitions for _GLIBCXX_READ_MEM_BARRIER and
_GLIBCXX_WRITE_MEM_BARRIER, rewrites the guards in terms of proper
atomic extensions and removes internal uses of
_GLIBCXX_READ_MEM_BARRIER and _GLIBCXX_WRITE_MEM_BARRIER and replaces
them with equivalent atomics.

2015-06-12  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>

	PR target/66200
	PR c++/66192
	* * config/cpu/generic/atomic_word.h (_GLIBCXX_READ_MEM_BARRIER): Define
        (_GLIBCXX_WRITE_MEM_BARRIER): Likewise
        * include/bits/shared_ptr_base.h: Use ACQ_REL barrier.
        * include/ext/atomicity.h: Likewise.
        * include/tr1/shared_ptr.h: Likewise.
        * libsupc++/guard.cc (__test_and_acquire): Rewrite with atomics.
        Update comment.
        (__set_and_release): Likewise.
        * testsuite/20_util/shared_ptr/cons/43820_neg.cc (test01): Adjust for
	line numbers.
        * testsuite/20_util/shared_ptr/cons/void_neg.cc: Likewise.
        * testsuite/tr1/2_general_utilities/shared_ptr/cons/43820_neg.cc:
	Likewise.

From-SVN: r224411
 2015-06-12 09:49:41 +00:00
Jakub Jelinek
5624e564d2 Update copyright years. 
From-SVN: r219188
 2015-01-05 13:33:28 +01:00
Richard Sandiford
aa118a03c4 Update copyright years in libstdc++-v3/ 
From-SVN: r206301
 2014-01-02 22:30:10 +00:00
Paolo Carlini
aeb1f2be12 atomicity.h: Add #pragma GCC system_header. 
2013-08-07  Paolo Carlini  <paolo.carlini@oracle.com>

	* include/ext/atomicity.h: Add #pragma GCC system_header.

From-SVN: r201567
 2013-08-07 14:26:15 +00:00
Richard Sandiford
405feeb871 Update copyright in libstdc++-v3. 
From-SVN: r195701
 2013-02-03 17:54:05 +00:00
Jakub Jelinek
7dcbaaa984 re PR libstdc++/51798 (libstdc++ atomicity performance regression due to __sync_fetch_and_add) 
PR libstdc++/51798
	* config/cpu/generic/atomicity_builtins/atomicity.h
	(__exchange_and_add, __atomic_add): Use __atomic_fetch_add
	with __ATOMIC_ACQ_REL semantics instead of __sync_fetch_and_add.
	* include/ext/atomicity.h (__exchange_and_add, __atomic_add):
	Likewise.

From-SVN: r183644
 2012-01-27 21:26:03 +01:00
Benjamin Kosnik
a152e96f01 acinclude.m4 (GLIBCXX_ENABLE_ATOMIC_BUILTINS): Remove size-specific macros. 
2011-11-30  Benjamin Kosnik  <bkoz@redhat.com>

        * acinclude.m4 (GLIBCXX_ENABLE_ATOMIC_BUILTINS): Remove
        size-specific macros. _GLIBCXX_ATOMIC_BUILTINS_1,
        _GLIBCXX_ATOMIC_BUILTINS_2, _GLIBCXX_ATOMIC_BUILTINS_4,
        _GLIBCXX_ATOMIC_BUILTINS_8. Use _GLIBCXX_ATOMIC_BUILTINS to
        indicate use of C++11 atomic builtins.
        * config.h.in: Regenerate.
        * configure: Regenerate.
        * include/Makefile.am (bits_sup_headers): Add atomic_lockfree_defines.h.
        * include/Makefile.in: Regenerate.
        * libsupc++/Makefile.am: Compile C++11 support with -std=gnu++0x.
        * libsupc++/Makefile.in: Regenerate.

        * include/bits/atomic_base.h: Move lock-free property macros...
        * libsupc++/atomic_lockfree_defines.h: ...here.
        * include/std/future: Use C++11 macros.
        * libsupc++/eh_ptr.cc: Same.
        * libsupc++/eh_throw.cc: Same.
        * libsupc++/exception: Same.
        * libsupc++/exception_ptr.h: Same.
        * libsupc++/guard.cc: Same.
        * libsupc++/nested_exception.cc: Same.
        * libsupc++/nested_exception.h: Same.
        * src/future.cc: Same.

        * include/ext/atomicity.h: Use _GLIBCXX_ATOMIC_BUILTINS.

        * doc/doxygen/user.cfg.in
        * doc/xml/manual/concurrency_extensions.xml

        * testsuite/18_support/exception_ptr/lifespan.cc
        * testsuite/lib/libstdc++.exp

From-SVN: r181869
 2011-12-01 02:20:32 +00:00
Benjamin Kosnik
12ffa22844 PR libstdc++/36104 part four 
2011-01-30  Benjamin Kosnik  <bkoz@redhat.com>

	PR libstdc++/36104 part four
	* include/bits/c++config (_GLIBCXX_STD): Remove.
	(_GLIBCXX_STD_D, _GLIBCXX_PR): Now _GLIBCXX_STD_C.
	(_GLIBCXX_P): Now _GLIBCXX_STD_A.
	(_GLIBCXX_NAMESPACE_DEBUG, _GLIBCXX_NAMESPACE_PARALLEL,
	 _GLIBCXX_NAMESPACE_PROFILE, _GLIBCXX_NAMESPACE_VERSION): Remove.
	(_GLIBCXX_INLINE_DEBUG, _GLIBCXX_INLINE_PARALLEL,
	 _GLIBCXX_INLINE_PROFILE): Remove.
	(_GLIBCXX_BEGIN_NAMESPACE(X)): Remove.
	(_GLIBCXX_END_NAMESPACE): Remove.
	(_GLIBCXX_BEGIN_NESTED_NAMESPACE(X, Y)): Remove.
	(_GLIBCXX_END_NESTED_NAMESPACE): Remove.
	(_GLIBCXX_BEGIN_NAMESPACE_ALGO): Add.
	(_GLIBCXX_END_NAMESPACE_ALGO): Add.
	(_GLIBCXX_BEGIN_NAMESPACE_CONTAINER): Add.
	(_GLIBCXX_END_NAMESPACE_CONTAINER): Add.
	(_GLIBCXX_BEGIN_NAMESPACE_VERSION): Add.
	(_GLIBCXX_END_NAMESPACE_VERSION): Add.
	(_GLIBCXX_BEGIN_LDBL_NAMESPACE): To _GLIBCXX_BEGIN_NAMESPACE_LDBL.
	(_GLIBCXX_END_LDBL_NAMESPACE): To _GLIBCXX_END_NAMESPACE_LDBL.
	(_GLIBCXX_VISIBILITY_ATTR): Revert to _GLIBCXX_VISIBILITY.
	* include/*: Use new macros for namespace scope.
	* config/*: Same.
	* src/*: Same.

	* src/Makefile.am (sources): Remove debug_list.cc, add
	compatibility-debug_list-2.cc.
	(parallel_sources): Remove parallel_list.cc, add
	compatibility-parallel_list-2.cc.
	(compatibility-parallel_list-2.[o,lo]): New rule.
	* src/Makefile.in: Regenerate.
	* src/debug_list.cc: Remove.
	* src/parallel_list.cc: Remove.
	* src/compatibility-list-2.cc: New.
	* src/compatibility-debug_list-2.cc: New.
	* src/compatibility-parallel_list-2.cc: New.

	* doc/doxygen/user.cfg.in: Adjust macros.

	* testsuite/20_util/auto_ptr/assign_neg.cc: Adjust line numbers, macros.
	* testsuite/20_util/declval/requirements/1_neg.cc: Same.
	* testsuite/20_util/duration/requirements/typedefs_neg1.cc: Same.
	* testsuite/20_util/duration/requirements/typedefs_neg2.cc: Same.
	* testsuite/20_util/duration/requirements/typedefs_neg3.cc: Same.
	* testsuite/20_util/forward/c_neg.cc: Same.
	* testsuite/20_util/forward/f_neg.cc: Same.
	* testsuite/20_util/make_signed/requirements/typedefs_neg.cc: Same.
	* testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc: Same.
	* testsuite/20_util/ratio/cons/cons_overflow_neg.cc: Same.
	* testsuite/20_util/ratio/operations/ops_overflow_neg.cc: Same.
	* testsuite/20_util/shared_ptr/cons/43820_neg.cc: Same.
	* testsuite/20_util/weak_ptr/comparison/cmp_neg.cc: Same.
	* testsuite/23_containers/deque/requirements/dr438/assign_neg.cc: Same.
	* testsuite/23_containers/deque/requirements/dr438/
	constructor_1_neg.cc: Same.
	* testsuite/23_containers/deque/requirements/dr438/
	constructor_2_neg.cc: Same.
	* testsuite/23_containers/deque/requirements/dr438/insert_neg.cc: Same.
	* testsuite/23_containers/forward_list/capacity/1.cc: Same.
	* testsuite/23_containers/forward_list/requirements/dr438/
	assign_neg.cc: Same.
	* testsuite/23_containers/forward_list/requirements/dr438/
	constructor_1_neg.cc: Same.
	* testsuite/23_containers/forward_list/requirements/dr438/
	constructor_2_neg.cc: Same.
	* testsuite/23_containers/forward_list/requirements/dr438/
	insert_neg.cc: Same.
	* testsuite/23_containers/list/capacity/29134.cc: Same.
	* testsuite/23_containers/list/requirements/dr438/assign_neg.cc: Same.
	* testsuite/23_containers/list/requirements/dr438/
	constructor_1_neg.cc: Same.
	* testsuite/23_containers/list/requirements/dr438/
	constructor_2_neg.cc: Same.
	* testsuite/23_containers/list/requirements/dr438/insert_neg.cc: Same.
	* testsuite/23_containers/vector/bool/capacity/29134.cc: Same.
	* testsuite/23_containers/vector/bool/modifiers/insert/31370.cc: Same.
	* testsuite/23_containers/vector/requirements/dr438/assign_neg.cc: Same.
	* testsuite/23_containers/vector/requirements/dr438/
	constructor_1_neg.cc: Same.
	* testsuite/23_containers/vector/requirements/dr438/
	constructor_2_neg.cc: Same.
	* testsuite/23_containers/vector/requirements/dr438/insert_neg.cc: Same.
	* testsuite/25_algorithms/sort/35588.cc: Same.
	* testsuite/27_io/ios_base/cons/assign_neg.cc: Same.
	* testsuite/27_io/ios_base/cons/copy_neg.cc: Same.
	* testsuite/ext/profile/mutex_extensions_neg.cc: Same.
	* testsuite/ext/profile/profiler_algos.cc: Same.
	* testsuite/ext/type_traits/add_unsigned_floating_neg.cc: Same.
	* testsuite/ext/type_traits/add_unsigned_integer_neg.cc: Same.
	* testsuite/ext/type_traits/remove_unsigned_floating_neg.cc: Same.
	* testsuite/ext/type_traits/remove_unsigned_integer_neg.cc: Same.
	* testsuite/tr1/2_general_utilities/shared_ptr/cons/43820_neg.cc: Same.

From-SVN: r169421
 2011-01-30 22:39:36 +00:00
Jakub Jelinek
d652f226fc Update Copyright years for files modified in 2010. 
From-SVN: r168438
 2011-01-03 21:52:22 +01:00
Benjamin Kosnik
f910786b98 *: Use headername alias to associate private includes to public includes. 
2010-11-18  Benjamin Kosnik  <bkoz@redhat.com>

	* config/*/*: Use headername alias to associate private includes
	to public includes.
	* include/*/*: Same.

	* scripts/run_doxygen: Update for doxygen 1.7.2.
	* doc/doxygen/user.cfg.in: Same.
	* doc/doxygen/TODO: Remove.

	* testsuite/*/std_c++0x_neg.cc: Adjust line number.

From-SVN: r168046
 2010-12-19 09:21:16 +00:00
Jan Hubicka
09f2a1e440 * include/ext/atomicity.h 
(__exchange_and_add, __atomic_add): Mark throw ().
	* config/os/aix/atomicity.h
	* config/os/aix/atomicity.h
	* config/os/irix/atomicity.h
	* config/cpu/cris/atomicity.h
	* config/cpu/m68k/atomicity.h
	* config/cpu/hppa/atomicity.h
	* config/cpu/sparc/atomicity.h
	* config/cpu/i386/atomicity.h
	* config/cpu/i486/atomicity.h
	* config/cpu/sh/atomicity.h
	* config/cpu/generic/atomicity_mutex/atomicity.h
	* config/cpu/generic/atomicity_builtins/atomicity.h
	(__exchange_and_add, __atomic_add): Mark throw ().

From-SVN: r146576
 2009-04-22 13:13:55 +00:00
Jakub Jelinek
748086b7b2 Licensing changes to GPLv3 resp. GPLv3 with GCC Runtime Exception. 
From-SVN: r145841
 2009-04-09 17:00:19 +02:00
Benjamin Kosnik
35648b4572 acinclude.m4 (GLIBCXX_ENABLE_ATOMIC_BUILTINS): Check for set of all used __sync builtins, in two sizes. 
2008-04-24  Benjamin Kosnik  <bkoz@redhat.com>

	* acinclude.m4 (GLIBCXX_ENABLE_ATOMIC_BUILTINS): Check for set of
	all used __sync builtins, in two sizes.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* src/atomic.cc: Use  _GLIBCXX_ATOMIC_BUILTINS_1.
	* include/ext/atomicity.h: Use  _GLIBCXX_ATOMIC_BUILTINS_4.
	* libsupc++/guard.cc: Use  _GLIBCXX_ATOMIC_BUILTINS_4.
	* doc/xml/manual/concurrency.xm: Update docs.

From-SVN: r134629
 2008-04-24 14:40:29 +00:00
Jonathan Wakely
ee5ca78921 valarray-inst.cc, [...]: Fix comment typos. 
* src/valarray-inst.cc, include/ext/atomicity.h,
	include/ext/concurrence.h, include/bits/basic_string.h,
	include/bits/fstream.tcc, include/ext/vstring.h: Fix comment typos.

From-SVN: r128915
 2007-10-01 21:49:39 +01:00
Benjamin Kosnik
2e362c7474 atomicity.h: Move to... 
2006-09-13  Benjamin Kosnik  <bkoz@redhat.com>

	* include/bits/atomicity.h: Move to...
	* include/ext/atomicity.h: ...here.	
	* include/bits/concurrence.h: Move to...
	* include/ext/concurrence.h: ...here.
	* include/Makefile.am (ext_headers): Additions.
	(bits_headers): Subtractions.
	* include/Makefile.in: Regenerate.

	* include/ext/bitmap_allocator.h (_Mutex), __threads_enabled,
	_Lock, _Auto_Lock): Subsume into...
	* include/bits/concurrence.h (__mutex): ..this. Error check
	locking and unlocking.	
	(lock): Uglify to...
	(__scoped_lock): Use __mutex. 
	(__glibcxx_mutex_define_initialized): Remove.
	(__glibcxx_mutex_type): Remove.

	* include/tr1/boost_shared_ptr.h: Formating tweaks, adjustments.
	(_Lock_policy): Move from here...
	* include/ext/concurrence.h: ... to here.
	(__shared_ptr_default_lock_mode): To __default_lock_policy.
	(_S_lockfree): To _S_atomic.
	Document.

	* libsupc++/guard.cc (static_mutex): Subsume into and fixup for...
	* include/ext/concurrence.h (__recursive_mutex): ...this. Error
	check locking and unlocking.
	* libsupc++/eh_alloc.cc: Use __scoped_lock.

	* config/os/aix/atomicity.h: Fixups for include paths, mutex to
	__scoped_mutex change, removal of locking defines.
	* config/os/irix/atomicity.h: Same.
	* config/cpu/cris/atomicity.h: Same.
	* config/cpu/m68k/atomicity.h: Same.
	* config/cpu/hppa/atomicity.h: Same.
	* config/cpu/mips/atomicity.h: Same.
	* config/cpu/sparc/atomicity.h: Same.
	* config/cpu/i386/atomicity.h: Same.
	* config/cpu/i486/atomicity.h: Same.
	* config/cpu/sh/atomicity.h: Same.
	* config/cpu/generic/atomicity_mutex/atomicity.h: Same.
	* include/ext/pool_allocator.h: Same.
	* include/ext/bitmap_allocator.h: Same.
	* include/ext/rc_string_base.h: Same.
	* include/ext/mt_allocator.h: Same.
	* include/bits/locale_classes.h: Same.
	* include/bits/basic_string.h: Same.
	* include/bits/ios_base.h: Same.
	* include/tr1/memory: Same.
	* src/pool_allocator.cc: Same.
	* src/mt_allocator.cc: Same.
	* src/locale_init.cc: Same.
	* src/ios.cc: Same.
	* src/locale.cc: Same.
	* src/bitmap_allocator.cc: Same.
	* src/ios_init.cc: Same.
	* src/debug.cc: Same.

From-SVN: r116942
 2006-09-14 09:48:15 +00:00