thread.cpp revision 249998 
1//===------------------------- thread.cpp----------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "thread"
11#include "exception"
12#include "vector"
13#include "future"
14#include "limits"
15#include <sys/types.h>
16#if !defined(_WIN32)
17#if !defined(__sun__) && !defined(__linux__)
18#include <sys/sysctl.h>
19#else
20#include <unistd.h>
21#endif // !__sun__ && !__linux__
22#endif // !_WIN32
23
24_LIBCPP_BEGIN_NAMESPACE_STD
25
26thread::~thread()
27{
28    if (__t_ != 0)
29        terminate();
30}
31
32void
33thread::join()
34{
35    int ec = pthread_join(__t_, 0);
36#ifndef _LIBCPP_NO_EXCEPTIONS
37    if (ec)
38        throw system_error(error_code(ec, system_category()), "thread::join failed");
39#else
40    (void)ec;
41#endif  // _LIBCPP_NO_EXCEPTIONS
42    __t_ = 0;
43}
44
45void
46thread::detach()
47{
48    int ec = EINVAL;
49    if (__t_ != 0)
50    {
51        ec = pthread_detach(__t_);
52        if (ec == 0)
53            __t_ = 0;
54    }
55#ifndef _LIBCPP_NO_EXCEPTIONS
56    if (ec)
57        throw system_error(error_code(ec, system_category()), "thread::detach failed");
58#endif  // _LIBCPP_NO_EXCEPTIONS
59}
60
61unsigned
62thread::hardware_concurrency() _NOEXCEPT
63{
64#if defined(CTL_HW) && defined(HW_NCPU)
65    unsigned n;
66    int mib[2] = {CTL_HW, HW_NCPU};
67    std::size_t s = sizeof(n);
68    sysctl(mib, 2, &n, &s, 0, 0);
69    return n;
70#elif (defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE >= 200112L) && defined(_SC_NPROCESSORS_ONLN)) || defined(EMSCRIPTEN)
71    long result = sysconf(_SC_NPROCESSORS_ONLN);
72    // sysconf returns -1 if the name is invalid, the option does not exist or
73    // does not have a definite limit.
74    // if sysconf returns some other negative number, we have no idea
75    // what is going on. Default to something safe.
76    if (result < 0)
77        return 0;
78    return static_cast<unsigned>(result);
79#else  // defined(CTL_HW) && defined(HW_NCPU)
80    // TODO: grovel through /proc or check cpuid on x86 and similar
81    // instructions on other architectures.
82    return 0;  // Means not computable [thread.thread.static]
83#endif  // defined(CTL_HW) && defined(HW_NCPU)
84}
85
86namespace this_thread
87{
88
89void
90sleep_for(const chrono::nanoseconds& ns)
91{
92    using namespace chrono;
93    if (ns > nanoseconds::zero())
94    {
95        seconds s = duration_cast<seconds>(ns);
96        timespec ts;
97        typedef decltype(ts.tv_sec) ts_sec;
98        _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
99        if (s.count() < ts_sec_max)
100        {
101            ts.tv_sec = static_cast<ts_sec>(s.count());
102            ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((ns-s).count());
103        }
104        else
105        {
106            ts.tv_sec = ts_sec_max;
107            ts.tv_nsec = giga::num - 1;
108        }
109        nanosleep(&ts, 0);
110    }
111}
112
113}  // this_thread
114
115__thread_specific_ptr<__thread_struct>&
116__thread_local_data()
117{
118    static __thread_specific_ptr<__thread_struct> __p;
119    return __p;
120}
121
122// __thread_struct_imp
123
124template <class T>
125class _LIBCPP_HIDDEN __hidden_allocator
126{
127public:
128    typedef T  value_type;
129
130    T* allocate(size_t __n)
131        {return static_cast<T*>(::operator new(__n * sizeof(T)));}
132    void deallocate(T* __p, size_t) {::operator delete((void*)__p);}
133
134    size_t max_size() const {return size_t(~0) / sizeof(T);}
135};
136
137class _LIBCPP_HIDDEN __thread_struct_imp
138{
139    typedef vector<__assoc_sub_state*,
140                          __hidden_allocator<__assoc_sub_state*> > _AsyncStates;
141    typedef vector<pair<condition_variable*, mutex*>,
142               __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify;
143
144    _AsyncStates async_states_;
145    _Notify notify_;
146
147    __thread_struct_imp(const __thread_struct_imp&);
148    __thread_struct_imp& operator=(const __thread_struct_imp&);
149public:
150    __thread_struct_imp() {}
151    ~__thread_struct_imp();
152
153    void notify_all_at_thread_exit(condition_variable* cv, mutex* m);
154    void __make_ready_at_thread_exit(__assoc_sub_state* __s);
155};
156
157__thread_struct_imp::~__thread_struct_imp()
158{
159    for (_Notify::iterator i = notify_.begin(), e = notify_.end();
160            i != e; ++i)
161    {
162        i->second->unlock();
163        i->first->notify_all();
164    }
165    for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end();
166            i != e; ++i)
167    {
168        (*i)->__make_ready();
169        (*i)->__release_shared();
170    }
171}
172
173void
174__thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
175{
176    notify_.push_back(pair<condition_variable*, mutex*>(cv, m));
177}
178
179void
180__thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s)
181{
182    async_states_.push_back(__s);
183    __s->__add_shared();
184}
185
186// __thread_struct
187
188__thread_struct::__thread_struct()
189    : __p_(new __thread_struct_imp)
190{
191}
192
193__thread_struct::~__thread_struct()
194{
195    delete __p_;
196}
197
198void
199__thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
200{
201    __p_->notify_all_at_thread_exit(cv, m);
202}
203
204void
205__thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s)
206{
207    __p_->__make_ready_at_thread_exit(__s);
208}
209
210_LIBCPP_END_NAMESPACE_STD
211