1 //===-------------------- condition_variable.cpp --------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "__config" 10 11 #ifndef _LIBCPP_HAS_NO_THREADS 12 13 #include "condition_variable" 14 #include "thread" 15 #include "system_error" 16 #include "__undef_macros" 17 18 #if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB) 19 #pragma comment(lib, "pthread") 20 #endif 21 22 _LIBCPP_BEGIN_NAMESPACE_STD 23 24 // ~condition_variable is defined elsewhere. 25 26 void 27 condition_variable::notify_one() _NOEXCEPT 28 { 29 __libcpp_condvar_signal(&__cv_); 30 } 31 32 void 33 condition_variable::notify_all() _NOEXCEPT 34 { 35 __libcpp_condvar_broadcast(&__cv_); 36 } 37 38 void 39 condition_variable::wait(unique_lock<mutex>& lk) _NOEXCEPT 40 { 41 if (!lk.owns_lock()) 42 __throw_system_error(EPERM, 43 "condition_variable::wait: mutex not locked"); 44 int ec = __libcpp_condvar_wait(&__cv_, lk.mutex()->native_handle()); 45 if (ec) 46 __throw_system_error(ec, "condition_variable wait failed"); 47 } 48 49 void 50 condition_variable::__do_timed_wait(unique_lock<mutex>& lk, 51 chrono::time_point<chrono::system_clock, chrono::nanoseconds> tp) _NOEXCEPT 52 { 53 using namespace chrono; 54 if (!lk.owns_lock()) 55 __throw_system_error(EPERM, 56 "condition_variable::timed wait: mutex not locked"); 57 nanoseconds d = tp.time_since_epoch(); 58 if (d > nanoseconds(0x59682F000000E941)) 59 d = nanoseconds(0x59682F000000E941); 60 __libcpp_timespec_t ts; 61 seconds s = duration_cast<seconds>(d); 62 typedef decltype(ts.tv_sec) ts_sec; 63 _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max(); 64 if (s.count() < ts_sec_max) 65 { 66 ts.tv_sec = static_cast<ts_sec>(s.count()); 67 ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((d - s).count()); 68 } 69 else 70 { 71 ts.tv_sec = ts_sec_max; 72 ts.tv_nsec = giga::num - 1; 73 } 74 int ec = __libcpp_condvar_timedwait(&__cv_, lk.mutex()->native_handle(), &ts); 75 if (ec != 0 && ec != ETIMEDOUT) 76 __throw_system_error(ec, "condition_variable timed_wait failed"); 77 } 78 79 void 80 notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk) 81 { 82 auto& tl_ptr = __thread_local_data(); 83 // If this thread was not created using std::thread then it will not have 84 // previously allocated. 85 if (tl_ptr.get() == nullptr) { 86 tl_ptr.set_pointer(new __thread_struct); 87 } 88 __thread_local_data()->notify_all_at_thread_exit(&cond, lk.release()); 89 } 90 91 _LIBCPP_END_NAMESPACE_STD 92 93 #endif // !_LIBCPP_HAS_NO_THREADS 94