thread.cpp revision 253159 
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#endif // !__sun__ && !__linux__
20#include <unistd.h>
21#endif // !_WIN32
22
23#if defined(__NetBSD__)
24#pragma weak pthread_create // Do not create libpthread dependency
25#endif
26#if defined(_WIN32)
27#include <windows.h>
28#endif
29
30_LIBCPP_BEGIN_NAMESPACE_STD
31
32thread::~thread()
33{
34    if (__t_ != 0)
35        terminate();
36}
37
38void
39thread::join()
40{
41    int ec = pthread_join(__t_, 0);
42#ifndef _LIBCPP_NO_EXCEPTIONS
43    if (ec)
44        throw system_error(error_code(ec, system_category()), "thread::join failed");
45#else
46    (void)ec;
47#endif  // _LIBCPP_NO_EXCEPTIONS
48    __t_ = 0;
49}
50
51void
52thread::detach()
53{
54    int ec = EINVAL;
55    if (__t_ != 0)
56    {
57        ec = pthread_detach(__t_);
58        if (ec == 0)
59            __t_ = 0;
60    }
61#ifndef _LIBCPP_NO_EXCEPTIONS
62    if (ec)
63        throw system_error(error_code(ec, system_category()), "thread::detach failed");
64#endif  // _LIBCPP_NO_EXCEPTIONS
65}
66
67unsigned
68thread::hardware_concurrency() _NOEXCEPT
69{
70#if defined(CTL_HW) && defined(HW_NCPU)
71    unsigned n;
72    int mib[2] = {CTL_HW, HW_NCPU};
73    std::size_t s = sizeof(n);
74    sysctl(mib, 2, &n, &s, 0, 0);
75    return n;
76#elif defined(_SC_NPROCESSORS_ONLN)
77    long result = sysconf(_SC_NPROCESSORS_ONLN);
78    // sysconf returns -1 if the name is invalid, the option does not exist or
79    // does not have a definite limit.
80    // if sysconf returns some other negative number, we have no idea
81    // what is going on. Default to something safe.
82    if (result < 0)
83        return 0;
84    return static_cast<unsigned>(result);
85#elif defined(_WIN32)
86    SYSTEM_INFO info;
87    GetSystemInfo(&info);
88    return info.dwNumberOfProcessors;
89#else  // defined(CTL_HW) && defined(HW_NCPU)
90    // TODO: grovel through /proc or check cpuid on x86 and similar
91    // instructions on other architectures.
92#warning hardware_concurrency not yet implemented
93    return 0;  // Means not computable [thread.thread.static]
94#endif  // defined(CTL_HW) && defined(HW_NCPU)
95}
96
97namespace this_thread
98{
99
100void
101sleep_for(const chrono::nanoseconds& ns)
102{
103    using namespace chrono;
104    if (ns > nanoseconds::zero())
105    {
106        seconds s = duration_cast<seconds>(ns);
107        timespec ts;
108        typedef decltype(ts.tv_sec) ts_sec;
109        _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
110        if (s.count() < ts_sec_max)
111        {
112            ts.tv_sec = static_cast<ts_sec>(s.count());
113            ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((ns-s).count());
114        }
115        else
116        {
117            ts.tv_sec = ts_sec_max;
118            ts.tv_nsec = giga::num - 1;
119        }
120        nanosleep(&ts, 0);
121    }
122}
123
124}  // this_thread
125
126__thread_specific_ptr<__thread_struct>&
127__thread_local_data()
128{
129    static __thread_specific_ptr<__thread_struct> __p;
130    return __p;
131}
132
133// __thread_struct_imp
134
135template <class T>
136class _LIBCPP_HIDDEN __hidden_allocator
137{
138public:
139    typedef T  value_type;
140
141    T* allocate(size_t __n)
142        {return static_cast<T*>(::operator new(__n * sizeof(T)));}
143    void deallocate(T* __p, size_t) {::operator delete((void*)__p);}
144
145    size_t max_size() const {return size_t(~0) / sizeof(T);}
146};
147
148class _LIBCPP_HIDDEN __thread_struct_imp
149{
150    typedef vector<__assoc_sub_state*,
151                          __hidden_allocator<__assoc_sub_state*> > _AsyncStates;
152    typedef vector<pair<condition_variable*, mutex*>,
153               __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify;
154
155    _AsyncStates async_states_;
156    _Notify notify_;
157
158    __thread_struct_imp(const __thread_struct_imp&);
159    __thread_struct_imp& operator=(const __thread_struct_imp&);
160public:
161    __thread_struct_imp() {}
162    ~__thread_struct_imp();
163
164    void notify_all_at_thread_exit(condition_variable* cv, mutex* m);
165    void __make_ready_at_thread_exit(__assoc_sub_state* __s);
166};
167
168__thread_struct_imp::~__thread_struct_imp()
169{
170    for (_Notify::iterator i = notify_.begin(), e = notify_.end();
171            i != e; ++i)
172    {
173        i->second->unlock();
174        i->first->notify_all();
175    }
176    for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end();
177            i != e; ++i)
178    {
179        (*i)->__make_ready();
180        (*i)->__release_shared();
181    }
182}
183
184void
185__thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
186{
187    notify_.push_back(pair<condition_variable*, mutex*>(cv, m));
188}
189
190void
191__thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s)
192{
193    async_states_.push_back(__s);
194    __s->__add_shared();
195}
196
197// __thread_struct
198
199__thread_struct::__thread_struct()
200    : __p_(new __thread_struct_imp)
201{
202}
203
204__thread_struct::~__thread_struct()
205{
206    delete __p_;
207}
208
209void
210__thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
211{
212    __p_->notify_all_at_thread_exit(cv, m);
213}
214
215void
216__thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s)
217{
218    __p_->__make_ready_at_thread_exit(__s);
219}
220
221_LIBCPP_END_NAMESPACE_STD
222