| //===------------------------- thread.cpp----------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include <__thread/poll_with_backoff.h> |
| #include <__thread/timed_backoff_policy.h> |
| #include <exception> |
| #include <future> |
| #include <limits> |
| #include <thread> |
| #include <vector> |
| |
| #if __has_include(<unistd.h>) |
| # include <unistd.h> // for sysconf |
| #endif |
| |
| #if defined(__NetBSD__) |
| # pragma weak pthread_create // Do not create libpthread dependency |
| #endif |
| |
| #if defined(_LIBCPP_WIN32API) |
| # include <windows.h> |
| #endif |
| |
| #if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB) |
| # pragma comment(lib, "pthread") |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| thread::~thread() { |
| if (!__libcpp_thread_isnull(&__t_)) |
| terminate(); |
| } |
| |
| void thread::join() { |
| int ec = EINVAL; |
| if (!__libcpp_thread_isnull(&__t_)) { |
| ec = __libcpp_thread_join(&__t_); |
| if (ec == 0) |
| __t_ = _LIBCPP_NULL_THREAD; |
| } |
| |
| if (ec) |
| __throw_system_error(ec, "thread::join failed"); |
| } |
| |
| void thread::detach() { |
| int ec = EINVAL; |
| if (!__libcpp_thread_isnull(&__t_)) { |
| ec = __libcpp_thread_detach(&__t_); |
| if (ec == 0) |
| __t_ = _LIBCPP_NULL_THREAD; |
| } |
| |
| if (ec) |
| __throw_system_error(ec, "thread::detach failed"); |
| } |
| |
| unsigned thread::hardware_concurrency() noexcept { |
| #if defined(_SC_NPROCESSORS_ONLN) |
| long result = sysconf(_SC_NPROCESSORS_ONLN); |
| // sysconf returns -1 if the name is invalid, the option does not exist or |
| // does not have a definite limit. |
| // if sysconf returns some other negative number, we have no idea |
| // what is going on. Default to something safe. |
| if (result < 0) |
| return 0; |
| return static_cast<unsigned>(result); |
| #elif defined(_LIBCPP_WIN32API) |
| SYSTEM_INFO info; |
| GetSystemInfo(&info); |
| return info.dwNumberOfProcessors; |
| #else // defined(CTL_HW) && defined(HW_NCPU) |
| // TODO: grovel through /proc or check cpuid on x86 and similar |
| // instructions on other architectures. |
| # if defined(_LIBCPP_WARNING) |
| _LIBCPP_WARNING("hardware_concurrency not yet implemented") |
| # else |
| # warning hardware_concurrency not yet implemented |
| # endif |
| return 0; // Means not computable [thread.thread.static] |
| #endif // defined(CTL_HW) && defined(HW_NCPU) |
| } |
| |
| namespace this_thread { |
| |
| void sleep_for(const chrono::nanoseconds& ns) { |
| if (ns > chrono::nanoseconds::zero()) { |
| __libcpp_thread_sleep_for(ns); |
| } |
| } |
| |
| } // namespace this_thread |
| |
| __thread_specific_ptr<__thread_struct>& __thread_local_data() { |
| // Even though __thread_specific_ptr's destructor doesn't actually destroy |
| // anything (see comments there), we can't call it at all because threads may |
| // outlive the static variable and calling its destructor means accessing an |
| // object outside of its lifetime, which is UB. |
| alignas(__thread_specific_ptr<__thread_struct>) static char __b[sizeof(__thread_specific_ptr<__thread_struct>)]; |
| static __thread_specific_ptr<__thread_struct>* __p = new (__b) __thread_specific_ptr<__thread_struct>(); |
| return *__p; |
| } |
| |
| // __thread_struct_imp |
| |
| template <class T> |
| class _LIBCPP_HIDDEN __hidden_allocator { |
| public: |
| typedef T value_type; |
| |
| T* allocate(size_t __n) { return static_cast<T*>(::operator new(__n * sizeof(T))); } |
| void deallocate(T* __p, size_t) { ::operator delete(static_cast<void*>(__p)); } |
| |
| size_t max_size() const { return size_t(~0) / sizeof(T); } |
| }; |
| |
| class _LIBCPP_HIDDEN __thread_struct_imp { |
| typedef vector<__assoc_sub_state*, __hidden_allocator<__assoc_sub_state*> > _AsyncStates; |
| typedef vector<pair<condition_variable*, mutex*>, __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify; |
| |
| _AsyncStates async_states_; |
| _Notify notify_; |
| |
| __thread_struct_imp(const __thread_struct_imp&); |
| __thread_struct_imp& operator=(const __thread_struct_imp&); |
| |
| public: |
| __thread_struct_imp() {} |
| ~__thread_struct_imp(); |
| |
| void notify_all_at_thread_exit(condition_variable* cv, mutex* m); |
| void __make_ready_at_thread_exit(__assoc_sub_state* __s); |
| }; |
| |
| __thread_struct_imp::~__thread_struct_imp() { |
| for (_Notify::iterator i = notify_.begin(), e = notify_.end(); i != e; ++i) { |
| i->first->notify_all(); |
| i->second->unlock(); |
| } |
| for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end(); i != e; ++i) { |
| (*i)->__make_ready(); |
| (*i)->__release_shared(); |
| } |
| } |
| |
| void __thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m) { |
| notify_.push_back(pair<condition_variable*, mutex*>(cv, m)); |
| } |
| |
| void __thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s) { |
| async_states_.push_back(__s); |
| __s->__add_shared(); |
| } |
| |
| // __thread_struct |
| |
| __thread_struct::__thread_struct() : __p_(new __thread_struct_imp) {} |
| |
| __thread_struct::~__thread_struct() { delete __p_; } |
| |
| void __thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m) { |
| __p_->notify_all_at_thread_exit(cv, m); |
| } |
| |
| void __thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s) { __p_->__make_ready_at_thread_exit(__s); } |
| |
| _LIBCPP_END_NAMESPACE_STD |