1349cc55cSDimitry Andric //===----------------------------------------------------------------------===// 20b57cec5SDimitry Andric // 30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 60b57cec5SDimitry Andric // 70b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 80b57cec5SDimitry Andric 90b57cec5SDimitry Andric #include "mutex" 100b57cec5SDimitry Andric #include "limits" 110b57cec5SDimitry Andric #include "system_error" 120b57cec5SDimitry Andric #include "include/atomic_support.h" 130b57cec5SDimitry Andric #include "__undef_macros" 140b57cec5SDimitry Andric 150b57cec5SDimitry Andric #ifndef _LIBCPP_HAS_NO_THREADS 16480093f4SDimitry Andric #if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB) 170b57cec5SDimitry Andric #pragma comment(lib, "pthread") 180b57cec5SDimitry Andric #endif 190b57cec5SDimitry Andric #endif 200b57cec5SDimitry Andric 210b57cec5SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 220b57cec5SDimitry Andric #ifndef _LIBCPP_HAS_NO_THREADS 230b57cec5SDimitry Andric 24e40139ffSDimitry Andric const defer_lock_t defer_lock{}; 25e40139ffSDimitry Andric const try_to_lock_t try_to_lock{}; 26e40139ffSDimitry Andric const adopt_lock_t adopt_lock{}; 270b57cec5SDimitry Andric 280b57cec5SDimitry Andric // ~mutex is defined elsewhere 290b57cec5SDimitry Andric 300b57cec5SDimitry Andric void 310b57cec5SDimitry Andric mutex::lock() 320b57cec5SDimitry Andric { 330b57cec5SDimitry Andric int ec = __libcpp_mutex_lock(&__m_); 340b57cec5SDimitry Andric if (ec) 350b57cec5SDimitry Andric __throw_system_error(ec, "mutex lock failed"); 360b57cec5SDimitry Andric } 370b57cec5SDimitry Andric 380b57cec5SDimitry Andric bool 39fe6060f1SDimitry Andric mutex::try_lock() noexcept 400b57cec5SDimitry Andric { 410b57cec5SDimitry Andric return __libcpp_mutex_trylock(&__m_); 420b57cec5SDimitry Andric } 430b57cec5SDimitry Andric 440b57cec5SDimitry Andric void 45fe6060f1SDimitry Andric mutex::unlock() noexcept 460b57cec5SDimitry Andric { 470b57cec5SDimitry Andric int ec = __libcpp_mutex_unlock(&__m_); 480b57cec5SDimitry Andric (void)ec; 490b57cec5SDimitry Andric _LIBCPP_ASSERT(ec == 0, "call to mutex::unlock failed"); 500b57cec5SDimitry Andric } 510b57cec5SDimitry Andric 520b57cec5SDimitry Andric // recursive_mutex 530b57cec5SDimitry Andric 540b57cec5SDimitry Andric recursive_mutex::recursive_mutex() 550b57cec5SDimitry Andric { 560b57cec5SDimitry Andric int ec = __libcpp_recursive_mutex_init(&__m_); 570b57cec5SDimitry Andric if (ec) 580b57cec5SDimitry Andric __throw_system_error(ec, "recursive_mutex constructor failed"); 590b57cec5SDimitry Andric } 600b57cec5SDimitry Andric 610b57cec5SDimitry Andric recursive_mutex::~recursive_mutex() 620b57cec5SDimitry Andric { 630b57cec5SDimitry Andric int e = __libcpp_recursive_mutex_destroy(&__m_); 640b57cec5SDimitry Andric (void)e; 650b57cec5SDimitry Andric _LIBCPP_ASSERT(e == 0, "call to ~recursive_mutex() failed"); 660b57cec5SDimitry Andric } 670b57cec5SDimitry Andric 680b57cec5SDimitry Andric void 690b57cec5SDimitry Andric recursive_mutex::lock() 700b57cec5SDimitry Andric { 710b57cec5SDimitry Andric int ec = __libcpp_recursive_mutex_lock(&__m_); 720b57cec5SDimitry Andric if (ec) 730b57cec5SDimitry Andric __throw_system_error(ec, "recursive_mutex lock failed"); 740b57cec5SDimitry Andric } 750b57cec5SDimitry Andric 760b57cec5SDimitry Andric void 77fe6060f1SDimitry Andric recursive_mutex::unlock() noexcept 780b57cec5SDimitry Andric { 790b57cec5SDimitry Andric int e = __libcpp_recursive_mutex_unlock(&__m_); 800b57cec5SDimitry Andric (void)e; 810b57cec5SDimitry Andric _LIBCPP_ASSERT(e == 0, "call to recursive_mutex::unlock() failed"); 820b57cec5SDimitry Andric } 830b57cec5SDimitry Andric 840b57cec5SDimitry Andric bool 85fe6060f1SDimitry Andric recursive_mutex::try_lock() noexcept 860b57cec5SDimitry Andric { 870b57cec5SDimitry Andric return __libcpp_recursive_mutex_trylock(&__m_); 880b57cec5SDimitry Andric } 890b57cec5SDimitry Andric 900b57cec5SDimitry Andric // timed_mutex 910b57cec5SDimitry Andric 920b57cec5SDimitry Andric timed_mutex::timed_mutex() 930b57cec5SDimitry Andric : __locked_(false) 940b57cec5SDimitry Andric { 950b57cec5SDimitry Andric } 960b57cec5SDimitry Andric 970b57cec5SDimitry Andric timed_mutex::~timed_mutex() 980b57cec5SDimitry Andric { 990b57cec5SDimitry Andric lock_guard<mutex> _(__m_); 1000b57cec5SDimitry Andric } 1010b57cec5SDimitry Andric 1020b57cec5SDimitry Andric void 1030b57cec5SDimitry Andric timed_mutex::lock() 1040b57cec5SDimitry Andric { 1050b57cec5SDimitry Andric unique_lock<mutex> lk(__m_); 1060b57cec5SDimitry Andric while (__locked_) 1070b57cec5SDimitry Andric __cv_.wait(lk); 1080b57cec5SDimitry Andric __locked_ = true; 1090b57cec5SDimitry Andric } 1100b57cec5SDimitry Andric 1110b57cec5SDimitry Andric bool 112fe6060f1SDimitry Andric timed_mutex::try_lock() noexcept 1130b57cec5SDimitry Andric { 1140b57cec5SDimitry Andric unique_lock<mutex> lk(__m_, try_to_lock); 1150b57cec5SDimitry Andric if (lk.owns_lock() && !__locked_) 1160b57cec5SDimitry Andric { 1170b57cec5SDimitry Andric __locked_ = true; 1180b57cec5SDimitry Andric return true; 1190b57cec5SDimitry Andric } 1200b57cec5SDimitry Andric return false; 1210b57cec5SDimitry Andric } 1220b57cec5SDimitry Andric 1230b57cec5SDimitry Andric void 124fe6060f1SDimitry Andric timed_mutex::unlock() noexcept 1250b57cec5SDimitry Andric { 1260b57cec5SDimitry Andric lock_guard<mutex> _(__m_); 1270b57cec5SDimitry Andric __locked_ = false; 1280b57cec5SDimitry Andric __cv_.notify_one(); 1290b57cec5SDimitry Andric } 1300b57cec5SDimitry Andric 1310b57cec5SDimitry Andric // recursive_timed_mutex 1320b57cec5SDimitry Andric 1330b57cec5SDimitry Andric recursive_timed_mutex::recursive_timed_mutex() 1340b57cec5SDimitry Andric : __count_(0), 1350b57cec5SDimitry Andric __id_{} 1360b57cec5SDimitry Andric { 1370b57cec5SDimitry Andric } 1380b57cec5SDimitry Andric 1390b57cec5SDimitry Andric recursive_timed_mutex::~recursive_timed_mutex() 1400b57cec5SDimitry Andric { 1410b57cec5SDimitry Andric lock_guard<mutex> _(__m_); 1420b57cec5SDimitry Andric } 1430b57cec5SDimitry Andric 1440b57cec5SDimitry Andric void 1450b57cec5SDimitry Andric recursive_timed_mutex::lock() 1460b57cec5SDimitry Andric { 1470b57cec5SDimitry Andric __thread_id id = this_thread::get_id(); 1480b57cec5SDimitry Andric unique_lock<mutex> lk(__m_); 1490b57cec5SDimitry Andric if (id ==__id_) 1500b57cec5SDimitry Andric { 1510b57cec5SDimitry Andric if (__count_ == numeric_limits<size_t>::max()) 1520b57cec5SDimitry Andric __throw_system_error(EAGAIN, "recursive_timed_mutex lock limit reached"); 1530b57cec5SDimitry Andric ++__count_; 1540b57cec5SDimitry Andric return; 1550b57cec5SDimitry Andric } 1560b57cec5SDimitry Andric while (__count_ != 0) 1570b57cec5SDimitry Andric __cv_.wait(lk); 1580b57cec5SDimitry Andric __count_ = 1; 1590b57cec5SDimitry Andric __id_ = id; 1600b57cec5SDimitry Andric } 1610b57cec5SDimitry Andric 1620b57cec5SDimitry Andric bool 163fe6060f1SDimitry Andric recursive_timed_mutex::try_lock() noexcept 1640b57cec5SDimitry Andric { 1650b57cec5SDimitry Andric __thread_id id = this_thread::get_id(); 1660b57cec5SDimitry Andric unique_lock<mutex> lk(__m_, try_to_lock); 1670b57cec5SDimitry Andric if (lk.owns_lock() && (__count_ == 0 || id == __id_)) 1680b57cec5SDimitry Andric { 1690b57cec5SDimitry Andric if (__count_ == numeric_limits<size_t>::max()) 1700b57cec5SDimitry Andric return false; 1710b57cec5SDimitry Andric ++__count_; 1720b57cec5SDimitry Andric __id_ = id; 1730b57cec5SDimitry Andric return true; 1740b57cec5SDimitry Andric } 1750b57cec5SDimitry Andric return false; 1760b57cec5SDimitry Andric } 1770b57cec5SDimitry Andric 1780b57cec5SDimitry Andric void 179fe6060f1SDimitry Andric recursive_timed_mutex::unlock() noexcept 1800b57cec5SDimitry Andric { 1810b57cec5SDimitry Andric unique_lock<mutex> lk(__m_); 1820b57cec5SDimitry Andric if (--__count_ == 0) 1830b57cec5SDimitry Andric { 1840b57cec5SDimitry Andric __id_.__reset(); 1850b57cec5SDimitry Andric lk.unlock(); 1860b57cec5SDimitry Andric __cv_.notify_one(); 1870b57cec5SDimitry Andric } 1880b57cec5SDimitry Andric } 1890b57cec5SDimitry Andric 1900b57cec5SDimitry Andric #endif // !_LIBCPP_HAS_NO_THREADS 1910b57cec5SDimitry Andric 1920b57cec5SDimitry Andric // If dispatch_once_f ever handles C++ exceptions, and if one can get to it 1930b57cec5SDimitry Andric // without illegal macros (unexpected macros not beginning with _UpperCase or 1940b57cec5SDimitry Andric // __lowercase), and if it stops spinning waiting threads, then call_once should 1950b57cec5SDimitry Andric // call into dispatch_once_f instead of here. Relevant radar this code needs to 1960b57cec5SDimitry Andric // keep in sync with: 7741191. 1970b57cec5SDimitry Andric 1980b57cec5SDimitry Andric #ifndef _LIBCPP_HAS_NO_THREADS 1990b57cec5SDimitry Andric _LIBCPP_SAFE_STATIC static __libcpp_mutex_t mut = _LIBCPP_MUTEX_INITIALIZER; 2000b57cec5SDimitry Andric _LIBCPP_SAFE_STATIC static __libcpp_condvar_t cv = _LIBCPP_CONDVAR_INITIALIZER; 2010b57cec5SDimitry Andric #endif 2020b57cec5SDimitry Andric 2030b57cec5SDimitry Andric void __call_once(volatile once_flag::_State_type& flag, void* arg, 2040b57cec5SDimitry Andric void (*func)(void*)) 2050b57cec5SDimitry Andric { 2060b57cec5SDimitry Andric #if defined(_LIBCPP_HAS_NO_THREADS) 2070b57cec5SDimitry Andric if (flag == 0) 2080b57cec5SDimitry Andric { 2090b57cec5SDimitry Andric #ifndef _LIBCPP_NO_EXCEPTIONS 2100b57cec5SDimitry Andric try 2110b57cec5SDimitry Andric { 2120b57cec5SDimitry Andric #endif // _LIBCPP_NO_EXCEPTIONS 2130b57cec5SDimitry Andric flag = 1; 2140b57cec5SDimitry Andric func(arg); 2150b57cec5SDimitry Andric flag = ~once_flag::_State_type(0); 2160b57cec5SDimitry Andric #ifndef _LIBCPP_NO_EXCEPTIONS 2170b57cec5SDimitry Andric } 2180b57cec5SDimitry Andric catch (...) 2190b57cec5SDimitry Andric { 2200b57cec5SDimitry Andric flag = 0; 2210b57cec5SDimitry Andric throw; 2220b57cec5SDimitry Andric } 2230b57cec5SDimitry Andric #endif // _LIBCPP_NO_EXCEPTIONS 2240b57cec5SDimitry Andric } 2250b57cec5SDimitry Andric #else // !_LIBCPP_HAS_NO_THREADS 2260b57cec5SDimitry Andric __libcpp_mutex_lock(&mut); 2270b57cec5SDimitry Andric while (flag == 1) 2280b57cec5SDimitry Andric __libcpp_condvar_wait(&cv, &mut); 2290b57cec5SDimitry Andric if (flag == 0) 2300b57cec5SDimitry Andric { 2310b57cec5SDimitry Andric #ifndef _LIBCPP_NO_EXCEPTIONS 2320b57cec5SDimitry Andric try 2330b57cec5SDimitry Andric { 2340b57cec5SDimitry Andric #endif // _LIBCPP_NO_EXCEPTIONS 2350b57cec5SDimitry Andric __libcpp_relaxed_store(&flag, once_flag::_State_type(1)); 2360b57cec5SDimitry Andric __libcpp_mutex_unlock(&mut); 2370b57cec5SDimitry Andric func(arg); 2380b57cec5SDimitry Andric __libcpp_mutex_lock(&mut); 2390b57cec5SDimitry Andric __libcpp_atomic_store(&flag, ~once_flag::_State_type(0), 2400b57cec5SDimitry Andric _AO_Release); 2410b57cec5SDimitry Andric __libcpp_mutex_unlock(&mut); 2420b57cec5SDimitry Andric __libcpp_condvar_broadcast(&cv); 2430b57cec5SDimitry Andric #ifndef _LIBCPP_NO_EXCEPTIONS 2440b57cec5SDimitry Andric } 2450b57cec5SDimitry Andric catch (...) 2460b57cec5SDimitry Andric { 2470b57cec5SDimitry Andric __libcpp_mutex_lock(&mut); 2480b57cec5SDimitry Andric __libcpp_relaxed_store(&flag, once_flag::_State_type(0)); 2490b57cec5SDimitry Andric __libcpp_mutex_unlock(&mut); 2500b57cec5SDimitry Andric __libcpp_condvar_broadcast(&cv); 2510b57cec5SDimitry Andric throw; 2520b57cec5SDimitry Andric } 2530b57cec5SDimitry Andric #endif // _LIBCPP_NO_EXCEPTIONS 2540b57cec5SDimitry Andric } 2550b57cec5SDimitry Andric else 2560b57cec5SDimitry Andric __libcpp_mutex_unlock(&mut); 2570b57cec5SDimitry Andric #endif // !_LIBCPP_HAS_NO_THREADS 2580b57cec5SDimitry Andric } 2590b57cec5SDimitry Andric 2600b57cec5SDimitry Andric _LIBCPP_END_NAMESPACE_STD 261