vendor/libc++/libc++-trunk-r375505vendor/libc++

1 files changed, 134 insertions, 22 deletions

diff --git a/include/__mutex_base b/include/__mutex_base
index f828beaf780d..ed75c82380a6 100644
--- a/include/__mutex_base
+++ b/include/__mutex_base
@@ -15,6 +15,7 @@
 #include <system_error>
 #include <__threading_support>
 
+#include <time.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
@@ -65,9 +66,9 @@ public:
 static_assert(is_nothrow_default_constructible<mutex>::value,
               "the default constructor for std::mutex must be nothrow");
 
-struct _LIBCPP_TYPE_VIS defer_lock_t {};
-struct _LIBCPP_TYPE_VIS try_to_lock_t {};
-struct _LIBCPP_TYPE_VIS adopt_lock_t {};
+struct _LIBCPP_TYPE_VIS defer_lock_t { explicit defer_lock_t() = default; };
+struct _LIBCPP_TYPE_VIS try_to_lock_t { explicit try_to_lock_t() = default; };
+struct _LIBCPP_TYPE_VIS adopt_lock_t { explicit adopt_lock_t() = default; };
 
 #if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
 
@@ -94,10 +95,11 @@ private:
     mutex_type& __m_;
 public:
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY
     explicit lock_guard(mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
         : __m_(__m) {__m_.lock();}
-    _LIBCPP_INLINE_VISIBILITY
+
+    _LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY
     lock_guard(mutex_type& __m, adopt_lock_t) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
         : __m_(__m) {}
     _LIBCPP_INLINE_VISIBILITY
@@ -336,23 +338,75 @@ public:
 private:
     void __do_timed_wait(unique_lock<mutex>& __lk,
        chrono::time_point<chrono::system_clock, chrono::nanoseconds>) _NOEXCEPT;
+#if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
+    void __do_timed_wait(unique_lock<mutex>& __lk,
+       chrono::time_point<chrono::steady_clock, chrono::nanoseconds>) _NOEXCEPT;
+#endif
+    template <class _Clock>
+    void __do_timed_wait(unique_lock<mutex>& __lk,
+       chrono::time_point<_Clock, chrono::nanoseconds>) _NOEXCEPT;
 };
 #endif // !_LIBCPP_HAS_NO_THREADS
 
-template <class _To, class _Rep, class _Period>
+template <class _Rep, class _Period>
 inline _LIBCPP_INLINE_VISIBILITY
 typename enable_if
 <
-    chrono::__is_duration<_To>::value,
-    _To
+    is_floating_point<_Rep>::value,
+    chrono::nanoseconds
 >::type
-__ceil(chrono::duration<_Rep, _Period> __d)
+__safe_nanosecond_cast(chrono::duration<_Rep, _Period> __d)
 {
     using namespace chrono;
-    _To __r = duration_cast<_To>(__d);
-    if (__r < __d)
-        ++__r;
-    return __r;
+    using __ratio = ratio_divide<_Period, nano>;
+    using __ns_rep = nanoseconds::rep;
+    _Rep __result_float = __d.count() * __ratio::num / __ratio::den;
+
+    _Rep __result_max = numeric_limits<__ns_rep>::max();
+    if (__result_float >= __result_max) {
+        return nanoseconds::max();
+    }
+
+    _Rep __result_min = numeric_limits<__ns_rep>::min();
+    if (__result_float <= __result_min) {
+        return nanoseconds::min();
+    }
+
+    return nanoseconds(static_cast<__ns_rep>(__result_float));
+}
+
+template <class _Rep, class _Period>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_floating_point<_Rep>::value,
+    chrono::nanoseconds
+>::type
+__safe_nanosecond_cast(chrono::duration<_Rep, _Period> __d)
+{
+    using namespace chrono;
+    if (__d.count() == 0) {
+        return nanoseconds(0);
+    }
+
+    using __ratio = ratio_divide<_Period, nano>;
+    using __ns_rep = nanoseconds::rep;
+    __ns_rep __result_max = std::numeric_limits<__ns_rep>::max();
+    if (__d.count() > 0 && __d.count() > __result_max / __ratio::num) {
+        return nanoseconds::max();
+    }
+
+    __ns_rep __result_min = std::numeric_limits<__ns_rep>::min();
+    if (__d.count() < 0 && __d.count() < __result_min / __ratio::num) {
+        return nanoseconds::min();
+    }
+
+    __ns_rep __result = __d.count() * __ratio::num / __ratio::den;
+    if (__result == 0) {
+        return nanoseconds(1);
+    }
+
+    return nanoseconds(__result);
 }
 
 #ifndef _LIBCPP_HAS_NO_THREADS
@@ -370,7 +424,15 @@ condition_variable::wait_until(unique_lock<mutex>& __lk,
                                const chrono::time_point<_Clock, _Duration>& __t)
 {
     using namespace chrono;
-    wait_for(__lk, __t - _Clock::now());
+    using __clock_tp_ns = time_point<_Clock, nanoseconds>;
+
+    typename _Clock::time_point __now = _Clock::now();
+    if (__t <= __now)
+        return cv_status::timeout;
+
+    __clock_tp_ns __t_ns = __clock_tp_ns(__safe_nanosecond_cast(__t.time_since_epoch()));
+
+    __do_timed_wait(__lk, __t_ns);
     return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
 }
 
@@ -396,15 +458,25 @@ condition_variable::wait_for(unique_lock<mutex>& __lk,
     using namespace chrono;
     if (__d <= __d.zero())
         return cv_status::timeout;
-    typedef time_point<system_clock, duration<long double, nano> > __sys_tpf;
-    typedef time_point<system_clock, nanoseconds> __sys_tpi;
-    __sys_tpf _Max = __sys_tpi::max();
+    using __ns_rep = nanoseconds::rep;
     steady_clock::time_point __c_now = steady_clock::now();
-    system_clock::time_point __s_now = system_clock::now();
-    if (_Max - __d > __s_now)
-        __do_timed_wait(__lk, __s_now + __ceil<nanoseconds>(__d));
-    else
-        __do_timed_wait(__lk, __sys_tpi::max());
+
+#if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
+    using __clock_tp_ns = time_point<steady_clock, nanoseconds>;
+    __ns_rep __now_count_ns = __safe_nanosecond_cast(__c_now.time_since_epoch()).count();
+#else
+    using __clock_tp_ns = time_point<system_clock, nanoseconds>;
+    __ns_rep __now_count_ns = __safe_nanosecond_cast(system_clock::now().time_since_epoch()).count();
+#endif
+
+    __ns_rep __d_ns_count = __safe_nanosecond_cast(__d).count();
+
+    if (__now_count_ns > numeric_limits<__ns_rep>::max() - __d_ns_count) {
+        __do_timed_wait(__lk, __clock_tp_ns::max());
+    } else {
+        __do_timed_wait(__lk, __clock_tp_ns(nanoseconds(__now_count_ns + __d_ns_count)));
+    }
+
     return steady_clock::now() - __c_now < __d ? cv_status::no_timeout :
                                                  cv_status::timeout;
 }
@@ -420,6 +492,46 @@ condition_variable::wait_for(unique_lock<mutex>& __lk,
                       _VSTD::move(__pred));
 }
 
+#if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
+inline
+void
+condition_variable::__do_timed_wait(unique_lock<mutex>& __lk,
+     chrono::time_point<chrono::steady_clock, chrono::nanoseconds> __tp) _NOEXCEPT
+{
+    using namespace chrono;
+    if (!__lk.owns_lock())
+        __throw_system_error(EPERM,
+                            "condition_variable::timed wait: mutex not locked");
+    nanoseconds __d = __tp.time_since_epoch();
+    timespec __ts;
+    seconds __s = duration_cast<seconds>(__d);
+    using __ts_sec = decltype(__ts.tv_sec);
+    const __ts_sec __ts_sec_max = numeric_limits<__ts_sec>::max();
+    if (__s.count() < __ts_sec_max)
+    {
+        __ts.tv_sec = static_cast<__ts_sec>(__s.count());
+        __ts.tv_nsec = (__d - __s).count();
+    }
+    else
+    {
+        __ts.tv_sec = __ts_sec_max;
+        __ts.tv_nsec = giga::num - 1;
+    }
+    int __ec = pthread_cond_clockwait(&__cv_, __lk.mutex()->native_handle(), CLOCK_MONOTONIC, &__ts);
+    if (__ec != 0 && __ec != ETIMEDOUT)
+        __throw_system_error(__ec, "condition_variable timed_wait failed");
+}
+#endif // _LIBCPP_HAS_COND_CLOCKWAIT
+
+template <class _Clock>
+inline
+void
+condition_variable::__do_timed_wait(unique_lock<mutex>& __lk,
+     chrono::time_point<_Clock, chrono::nanoseconds> __tp) _NOEXCEPT
+{
+    wait_for(__lk, __tp - _Clock::now());
+}
+
 #endif // !_LIBCPP_HAS_NO_THREADS
 
 _LIBCPP_END_NAMESPACE_STD