Gecko [ v99win.today ]

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algorithmfwd.h	23.97 KB	-rw-r--r--
align.h	3.62 KB	-rw-r--r--
alloc_traits.h	26.98 KB	-rw-r--r--
allocated_ptr.h	3.25 KB	-rw-r--r--
allocator.h	9.51 KB	-rw-r--r--
atomic_base.h	56.07 KB	-rw-r--r--
atomic_futex.h	12.1 KB	-rw-r--r--
atomic_lockfree_defines.h	2.3 KB	-rw-r--r--
atomic_timed_wait.h	13.21 KB	-rw-r--r--
atomic_wait.h	12.26 KB	-rw-r--r--
basic_ios.h	15.7 KB	-rw-r--r--
basic_ios.tcc	5.94 KB	-rw-r--r--
basic_string.h	246.04 KB	-rw-r--r--
basic_string.tcc	52.92 KB	-rw-r--r--
boost_concept_check.h	26.54 KB	-rw-r--r--
c++0x_warning.h	1.44 KB	-rw-r--r--
char_traits.h	28.66 KB	-rw-r--r--
charconv.h	3.35 KB	-rw-r--r--
codecvt.h	24.9 KB	-rw-r--r--
concept_check.h	3.34 KB	-rw-r--r--
cpp_type_traits.h	13.67 KB	-rw-r--r--
cxxabi_forced.h	1.77 KB	-rw-r--r--
cxxabi_init_exception.h	2.17 KB	-rw-r--r--
deque.tcc	41.37 KB	-rw-r--r--
enable_special_members.h	12.16 KB	-rw-r--r--
erase_if.h	2.02 KB	-rw-r--r--
exception.h	2.45 KB	-rw-r--r--
exception_defines.h	1.61 KB	-rw-r--r--
exception_ptr.h	7.46 KB	-rw-r--r--
forward_list.h	49.21 KB	-rw-r--r--
forward_list.tcc	13.71 KB	-rw-r--r--
fs_dir.h	16.02 KB	-rw-r--r--
fs_fwd.h	10.52 KB	-rw-r--r--
fs_ops.h	10.49 KB	-rw-r--r--
fs_path.h	38.81 KB	-rw-r--r--
fstream.tcc	32.88 KB	-rw-r--r--
functexcept.h	3.43 KB	-rw-r--r--
functional_hash.h	8.39 KB	-rw-r--r--
gslice.h	5.39 KB	-rw-r--r--
gslice_array.h	7.71 KB	-rw-r--r--
hash_bytes.h	2.1 KB	-rw-r--r--
hashtable.h	82.96 KB	-rw-r--r--
hashtable_policy.h	60.7 KB	-rw-r--r--
indirect_array.h	7.72 KB	-rw-r--r--
invoke.h	5.92 KB	-rw-r--r--
ios_base.h	31.19 KB	-rw-r--r--
istream.tcc	30.85 KB	-rw-r--r--
iterator_concepts.h	32.55 KB	-rw-r--r--
list.tcc	16.8 KB	-rw-r--r--
locale_classes.h	24.46 KB	-rw-r--r--
locale_classes.tcc	8.18 KB	-rw-r--r--
locale_conv.h	18.38 KB	-rw-r--r--
locale_facets.h	91.46 KB	-rw-r--r--
locale_facets.tcc	39.51 KB	-rw-r--r--
locale_facets_nonio.h	68.07 KB	-rw-r--r--
locale_facets_nonio.tcc	46.42 KB	-rw-r--r--
localefwd.h	5.8 KB	-rw-r--r--
mask_array.h	7.54 KB	-rw-r--r--
max_size_type.h	22.18 KB	-rw-r--r--
memoryfwd.h	2.45 KB	-rw-r--r--
move.h	6.64 KB	-rw-r--r--
nested_exception.h	4.77 KB	-rw-r--r--
node_handle.h	10.66 KB	-rw-r--r--
ostream.tcc	12.03 KB	-rw-r--r--
ostream_insert.h	3.94 KB	-rw-r--r--
parse_numbers.h	7.79 KB	-rw-r--r--
postypes.h	8.27 KB	-rw-r--r--
predefined_ops.h	9.94 KB	-rw-r--r--
ptr_traits.h	6.55 KB	-rw-r--r--
quoted_string.h	4.93 KB	-rw-r--r--
random.h	174.18 KB	-rw-r--r--
random.tcc	103.21 KB	-rw-r--r--
range_access.h	10.46 KB	-rw-r--r--
ranges_algo.h	114.09 KB	-rw-r--r--
ranges_algobase.h	18.43 KB	-rw-r--r--
ranges_base.h	23.82 KB	-rw-r--r--
ranges_cmp.h	5.88 KB	-rw-r--r--
ranges_uninitialized.h	17.71 KB	-rw-r--r--
ranges_util.h	20.11 KB	-rw-r--r--
refwrap.h	12.9 KB	-rw-r--r--
regex.h	101.53 KB	-rw-r--r--
regex.tcc	16.11 KB	-rw-r--r--
regex_automaton.h	10.54 KB	-rw-r--r--
regex_automaton.tcc	7.54 KB	-rw-r--r--
regex_compiler.h	15.84 KB	-rw-r--r--
regex_compiler.tcc	18.71 KB	-rw-r--r--
regex_constants.h	15.18 KB	-rw-r--r--
regex_error.h	4.9 KB	-rw-r--r--
regex_executor.h	8.64 KB	-rw-r--r--
regex_executor.tcc	18.4 KB	-rw-r--r--
regex_scanner.h	6.88 KB	-rw-r--r--
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semaphore_base.h	7.75 KB	-rw-r--r--
shared_ptr.h	30.25 KB	-rw-r--r--
shared_ptr_atomic.h	9.64 KB	-rw-r--r--
shared_ptr_base.h	53.62 KB	-rw-r--r--
slice_array.h	9.39 KB	-rw-r--r--
specfun.h	46.13 KB	-rw-r--r--
sstream.tcc	9.91 KB	-rw-r--r--
std_abs.h	3.3 KB	-rw-r--r--
std_function.h	22.33 KB	-rw-r--r--
std_mutex.h	6.29 KB	-rw-r--r--
std_thread.h	8.39 KB	-rw-r--r--
stl_algo.h	209.67 KB	-rw-r--r--
stl_algobase.h	74.47 KB	-rw-r--r--
stl_bvector.h	34.74 KB	-rw-r--r--
stl_construct.h	8.59 KB	-rw-r--r--
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stl_function.h	42.87 KB	-rw-r--r--
stl_heap.h	20.27 KB	-rw-r--r--
stl_iterator.h	77 KB	-rw-r--r--
stl_iterator_base_funcs.h	7.99 KB	-rw-r--r--
stl_iterator_base_types.h	9.44 KB	-rw-r--r--
stl_list.h	68.14 KB	-rw-r--r--
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stl_numeric.h	14.26 KB	-rw-r--r--
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stl_queue.h	24.45 KB	-rw-r--r--
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stl_relops.h	4.49 KB	-rw-r--r--
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stl_stack.h	12.39 KB	-rw-r--r--
stl_tempbuf.h	8.45 KB	-rw-r--r--
stl_tree.h	72.19 KB	-rw-r--r--
stl_uninitialized.h	33.22 KB	-rw-r--r--
stl_vector.h	64.37 KB	-rw-r--r--
stream_iterator.h	7.52 KB	-rw-r--r--
streambuf.tcc	4.81 KB	-rw-r--r--
streambuf_iterator.h	15.17 KB	-rw-r--r--
string_view.tcc	7 KB	-rw-r--r--
stringfwd.h	2.63 KB	-rw-r--r--
this_thread_sleep.h	3.23 KB	-rw-r--r--
uniform_int_dist.h	12.75 KB	-rw-r--r--
unique_lock.h	6 KB	-rw-r--r--
unique_ptr.h	31.77 KB	-rw-r--r--
unordered_map.h	74.87 KB	-rw-r--r--
unordered_set.h	61.46 KB	-rw-r--r--
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vector.tcc	30.26 KB	-rw-r--r--

Code Editor : atomic_futex.h

// -*- C++ -*- header.

// Copyright (C) 2015-2021 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
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file bits/atomic_futex.h
 *  This is an internal header file, included by other library headers.
 *  Do not attempt to use it directly.
 */

#ifndef _GLIBCXX_ATOMIC_FUTEX_H
#define _GLIBCXX_ATOMIC_FUTEX_H 1

#pragma GCC system_header

#include <bits/c++config.h>
#include <atomic>
#include <chrono>
#if ! (defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1)
#include <mutex>
#include <condition_variable>
#endif

#ifndef _GLIBCXX_ALWAYS_INLINE
#define _GLIBCXX_ALWAYS_INLINE inline __attribute__((__always_inline__))
#endif

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

#ifdef _GLIBCXX_HAS_GTHREADS
#if defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1
  struct __atomic_futex_unsigned_base
  {
    // __s and __ns are measured against CLOCK_REALTIME. Returns false
    // iff a timeout occurred.
    bool
    _M_futex_wait_until(unsigned *__addr, unsigned __val, bool __has_timeout,
	chrono::seconds __s, chrono::nanoseconds __ns);

// __s and __ns are measured against CLOCK_MONOTONIC. Returns
    // false iff a timeout occurred.
    bool
    _M_futex_wait_until_steady(unsigned *__addr, unsigned __val,
	bool __has_timeout, chrono::seconds __s, chrono::nanoseconds __ns);

// This can be executed after the object has been destroyed.
    static void _M_futex_notify_all(unsigned* __addr);
  };

template <unsigned _Waiter_bit = 0x80000000>
  class __atomic_futex_unsigned : __atomic_futex_unsigned_base
  {
    typedef chrono::steady_clock __clock_t;

// This must be lock-free and at offset 0.
    atomic<unsigned> _M_data;

public:
    explicit
    __atomic_futex_unsigned(unsigned __data) : _M_data(__data)
    { }

_GLIBCXX_ALWAYS_INLINE unsigned
    _M_load(memory_order __mo)
    {
      return _M_data.load(__mo) & ~_Waiter_bit;
    }

private:
    // If a timeout occurs, returns a current value after the timeout;
    // otherwise, returns the operand's value if equal is true or a different
    // value if equal is false.
    // The assumed value is the caller's assumption about the current value
    // when making the call.
    // __s and __ns are measured against CLOCK_REALTIME.
    unsigned
    _M_load_and_test_until(unsigned __assumed, unsigned __operand,
	bool __equal, memory_order __mo, bool __has_timeout,
	chrono::seconds __s, chrono::nanoseconds __ns)
    {
      for (;;)
	{
	  // Don't bother checking the value again because we expect the caller
	  // to have done it recently.
	  // memory_order_relaxed is sufficient because we can rely on just the
	  // modification order (store_notify uses an atomic RMW operation too),
	  // and the futex syscalls synchronize between themselves.
	  _M_data.fetch_or(_Waiter_bit, memory_order_relaxed);
	  bool __ret = _M_futex_wait_until((unsigned*)(void*)&_M_data,
					   __assumed | _Waiter_bit,
					   __has_timeout, __s, __ns);
	  // Fetch the current value after waiting (clears _Waiter_bit).
	  __assumed = _M_load(__mo);
	  if (!__ret || ((__operand == __assumed) == __equal))
	    return __assumed;
	  // TODO adapt wait time
	}
    }

// If a timeout occurs, returns a current value after the timeout;
    // otherwise, returns the operand's value if equal is true or a different
    // value if equal is false.
    // The assumed value is the caller's assumption about the current value
    // when making the call.
    // __s and __ns are measured against CLOCK_MONOTONIC.
    unsigned
    _M_load_and_test_until_steady(unsigned __assumed, unsigned __operand,
	bool __equal, memory_order __mo, bool __has_timeout,
	chrono::seconds __s, chrono::nanoseconds __ns)
    {
      for (;;)
	{
	  // Don't bother checking the value again because we expect the caller
	  // to have done it recently.
	  // memory_order_relaxed is sufficient because we can rely on just the
	  // modification order (store_notify uses an atomic RMW operation too),
	  // and the futex syscalls synchronize between themselves.
	  _M_data.fetch_or(_Waiter_bit, memory_order_relaxed);
	  bool __ret = _M_futex_wait_until_steady((unsigned*)(void*)&_M_data,
					   __assumed | _Waiter_bit,
					   __has_timeout, __s, __ns);
	  // Fetch the current value after waiting (clears _Waiter_bit).
	  __assumed = _M_load(__mo);
	  if (!__ret || ((__operand == __assumed) == __equal))
	    return __assumed;
	  // TODO adapt wait time
	}
    }

// Returns the operand's value if equal is true or a different value if
    // equal is false.
    // The assumed value is the caller's assumption about the current value
    // when making the call.
    unsigned
    _M_load_and_test(unsigned __assumed, unsigned __operand,
	bool __equal, memory_order __mo)
    {
      return _M_load_and_test_until(__assumed, __operand, __equal, __mo,
				    false, {}, {});
    }

template<typename _Dur>
    unsigned
    _M_load_and_test_until_impl(unsigned __assumed, unsigned __operand,
	bool __equal, memory_order __mo,
	const chrono::time_point<std::chrono::steady_clock, _Dur>& __atime)
    {
      auto __s = chrono::time_point_cast<chrono::seconds>(__atime);
      auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
      // XXX correct?
      return _M_load_and_test_until_steady(__assumed, __operand, __equal, __mo,
	  true, __s.time_since_epoch(), __ns);
    }

public:

_GLIBCXX_ALWAYS_INLINE unsigned
    _M_load_when_not_equal(unsigned __val, memory_order __mo)
    {
      unsigned __i = _M_load(__mo);
      if ((__i & ~_Waiter_bit) != __val)
	return (__i & ~_Waiter_bit);
      // TODO Spin-wait first.
      return _M_load_and_test(__i, __val, false, __mo);
    }

_GLIBCXX_ALWAYS_INLINE void
    _M_load_when_equal(unsigned __val, memory_order __mo)
    {
      unsigned __i = _M_load(__mo);
      if ((__i & ~_Waiter_bit) == __val)
	return;
      // TODO Spin-wait first.
      _M_load_and_test(__i, __val, true, __mo);
    }

// Returns false iff a timeout occurred.
    template<typename _Rep, typename _Period>
      _GLIBCXX_ALWAYS_INLINE bool
      _M_load_when_equal_for(unsigned __val, memory_order __mo,
	  const chrono::duration<_Rep, _Period>& __rtime)
      {
	using __dur = typename __clock_t::duration;
	return _M_load_when_equal_until(__val, __mo,
		    __clock_t::now() + chrono::__detail::ceil<__dur>(__rtime));
      }

// Returns false iff a timeout occurred.
    template<typename _Clock, typename _Duration>
      _GLIBCXX_ALWAYS_INLINE bool
      _M_load_when_equal_until(unsigned __val, memory_order __mo,
	  const chrono::time_point<_Clock, _Duration>& __atime)
      {
	typename _Clock::time_point __c_entry = _Clock::now();
	do {
	  const __clock_t::time_point __s_entry = __clock_t::now();
	  const auto __delta = __atime - __c_entry;
	  const auto __s_atime = __s_entry +
	      chrono::__detail::ceil<__clock_t::duration>(__delta);
	  if (_M_load_when_equal_until(__val, __mo, __s_atime))
	    return true;
	  __c_entry = _Clock::now();
	} while (__c_entry < __atime);
	return false;
      }

// Returns false iff a timeout occurred.
    template<typename _Duration>
    _GLIBCXX_ALWAYS_INLINE bool
    _M_load_when_equal_until(unsigned __val, memory_order __mo,
	const chrono::time_point<std::chrono::system_clock, _Duration>& __atime)
    {
      unsigned __i = _M_load(__mo);
      if ((__i & ~_Waiter_bit) == __val)
	return true;
      // TODO Spin-wait first.  Ignore effect on timeout.
      __i = _M_load_and_test_until_impl(__i, __val, true, __mo, __atime);
      return (__i & ~_Waiter_bit) == __val;
    }

// Returns false iff a timeout occurred.
    template<typename _Duration>
    _GLIBCXX_ALWAYS_INLINE bool
    _M_load_when_equal_until(unsigned __val, memory_order __mo,
	const chrono::time_point<std::chrono::steady_clock, _Duration>& __atime)
    {
      unsigned __i = _M_load(__mo);
      if ((__i & ~_Waiter_bit) == __val)
	return true;
      // TODO Spin-wait first.  Ignore effect on timeout.
      __i = _M_load_and_test_until_impl(__i, __val, true, __mo, __atime);
      return (__i & ~_Waiter_bit) == __val;
    }

_GLIBCXX_ALWAYS_INLINE void
    _M_store_notify_all(unsigned __val, memory_order __mo)
    {
      unsigned* __futex = (unsigned *)(void *)&_M_data;
      if (_M_data.exchange(__val, __mo) & _Waiter_bit)
	_M_futex_notify_all(__futex);
    }
  };

#else // ! (_GLIBCXX_HAVE_LINUX_FUTEX && ATOMIC_INT_LOCK_FREE > 1)

// If futexes are not available, use a mutex and a condvar to wait.
  // Because we access the data only within critical sections, all accesses
  // are sequentially consistent; thus, we satisfy any provided memory_order.
  template <unsigned _Waiter_bit = 0x80000000>
  class __atomic_futex_unsigned
  {
    typedef chrono::system_clock __clock_t;

unsigned _M_data;
    mutex _M_mutex;
    condition_variable _M_condvar;

public:
    explicit
    __atomic_futex_unsigned(unsigned __data) : _M_data(__data)
    { }

_GLIBCXX_ALWAYS_INLINE unsigned
    _M_load(memory_order __mo)
    {
      unique_lock<mutex> __lock(_M_mutex);
      return _M_data;
    }

_GLIBCXX_ALWAYS_INLINE unsigned
    _M_load_when_not_equal(unsigned __val, memory_order __mo)
    {
      unique_lock<mutex> __lock(_M_mutex);
      while (_M_data == __val)
	_M_condvar.wait(__lock);
      return _M_data;
    }

_GLIBCXX_ALWAYS_INLINE void
    _M_load_when_equal(unsigned __val, memory_order __mo)
    {
      unique_lock<mutex> __lock(_M_mutex);
      while (_M_data != __val)
	_M_condvar.wait(__lock);
    }

template<typename _Rep, typename _Period>
      _GLIBCXX_ALWAYS_INLINE bool
      _M_load_when_equal_for(unsigned __val, memory_order __mo,
	  const chrono::duration<_Rep, _Period>& __rtime)
      {
	unique_lock<mutex> __lock(_M_mutex);
	return _M_condvar.wait_for(__lock, __rtime,
				   [&] { return _M_data == __val;});
      }

template<typename _Clock, typename _Duration>
      _GLIBCXX_ALWAYS_INLINE bool
      _M_load_when_equal_until(unsigned __val, memory_order __mo,
	  const chrono::time_point<_Clock, _Duration>& __atime)
      {
	unique_lock<mutex> __lock(_M_mutex);
	return _M_condvar.wait_until(__lock, __atime,
				     [&] { return _M_data == __val;});
      }

_GLIBCXX_ALWAYS_INLINE void
    _M_store_notify_all(unsigned __val, memory_order __mo)
    {
      unique_lock<mutex> __lock(_M_mutex);
      _M_data = __val;
      _M_condvar.notify_all();
    }
  };

#endif // _GLIBCXX_HAVE_LINUX_FUTEX && ATOMIC_INT_LOCK_FREE > 1
#endif // _GLIBCXX_HAS_GTHREADS

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std

#endif

${this.title}

Code Editor : atomic_futex.h