common/althreads.h

   1 #ifndef AL_THREADS_H
   2 #define AL_THREADS_H
   3
   4 #include <cstdint>
   5 #include <stdexcept>
   6 #include <type_traits>
   7
   8 #ifdef _WIN32
   9 #define WIN32_LEAN_AND_MEAN
  10 #include <windows.h>
  11
  12 #elif defined(__APPLE__)
  13
  14 #include <pthread.h>
  15
  16 #else
  17
  18 #include <threads.h>
  19 #endif
  20
  21 #include "albit.h"
  22
  23 namespace al {
  24
  25 template<typename T>
  26 class tss {
  27     static_assert(sizeof(T) <= sizeof(void*));
  28     static_assert(std::is_trivially_destructible_v<T> && std::is_trivially_copy_constructible_v<T>);
  29
  30     [[nodiscard]]
  31     static auto to_ptr(const T &value) noexcept -> void*
  32     {
  33         if constexpr(std::is_pointer_v<T>)
  34         {
  35             if constexpr(std::is_const_v<std::remove_pointer_t<T>>)
  36                 return const_cast<void*>(static_cast<const void*>(value)); /* NOLINT(*-const-cast) */
  37             else
  38                 return static_cast<void*>(value);
  39         }
  40         else if constexpr(sizeof(T) == sizeof(void*))
  41             return al::bit_cast<void*>(value);
  42         else if constexpr(std::is_integral_v<T>)
  43             return al::bit_cast<void*>(static_cast<std::uintptr_t>(value));
  44     }
  45
  46     [[nodiscard]]
  47     static auto from_ptr(void *ptr) noexcept -> T
  48     {
  49         if constexpr(std::is_pointer_v<T>)
  50             return static_cast<T>(ptr);
  51         else if constexpr(sizeof(T) == sizeof(void*))
  52             return al::bit_cast<T>(ptr);
  53         else if constexpr(std::is_integral_v<T>)
  54             return static_cast<T>(al::bit_cast<std::uintptr_t>(ptr));
  55     }
  56
  57 #ifdef _WIN32
  58     DWORD mTss{TLS_OUT_OF_INDEXES};
  59
  60 public:
  61     tss() : mTss{TlsAlloc()}
  62     {
  63         if(mTss == TLS_OUT_OF_INDEXES)
  64             throw std::runtime_error{"al::tss::tss()"};
  65     }
  66     explicit tss(const T &init) : tss{}
  67     {
  68         if(TlsSetValue(mTss, to_ptr(init)) == FALSE)
  69             throw std::runtime_error{"al::tss::tss(T)"};
  70     }
  71     ~tss() { TlsFree(mTss); }
  72
  73     void set(const T &value) const
  74     {
  75         if(TlsSetValue(mTss, to_ptr(value)) == FALSE)
  76             throw std::runtime_error{"al::tss::set(T)"};
  77     }
  78
  79     [[nodiscard]]
  80     auto get() const noexcept -> T { return from_ptr(TlsGetValue(mTss)); }
  81
  82 #elif defined(__APPLE__)
  83
  84     pthread_key_t mTss{};
  85
  86 public:
  87     tss()
  88     {
  89         if(int res{pthread_key_create(&mTss, nullptr)}; res != 0)
  90             throw std::runtime_error{"al::tss::tss()"};
  91     }
  92     explicit tss(const T &init) : tss{}
  93     {
  94         if(int res{pthread_setspecific(mTss, to_ptr(init))}; res != 0)
  95             throw std::runtime_error{"al::tss::tss(T)"};
  96     }
  97     ~tss() { pthread_key_delete(mTss); }
  98
  99     void set(const T &value) const
 100     {
 101         if(int res{pthread_setspecific(mTss, to_ptr(value))}; res != 0)
 102             throw std::runtime_error{"al::tss::set(T)"};
 103     }
 104
 105     [[nodiscard]]
 106     auto get() const noexcept -> T { return from_ptr(pthread_getspecific(mTss)); }
 107
 108 #else
 109
 110     tss_t mTss{};
 111
 112 public:
 113     tss()
 114     {
 115         if(int res{tss_create(&mTss, nullptr)}; res != thrd_success)
 116             throw std::runtime_error{"al::tss::tss()"};
 117     }
 118     explicit tss(const T &init) : tss{}
 119     {
 120         if(int res{tss_set(mTss, to_ptr(init))}; res != thrd_success)
 121             throw std::runtime_error{"al::tss::tss(T)"};
 122     }
 123     ~tss() { tss_delete(mTss); }
 124
 125     void set(const T &value) const
 126     {
 127         if(int res{tss_set(mTss, to_ptr(value))}; res != thrd_success)
 128             throw std::runtime_error{"al::tss::set(T)"};
 129     }
 130
 131     [[nodiscard]]
 132     auto get() const noexcept -> T { return from_ptr(tss_get(mTss)); }
 133 #endif /* _WIN32 */
 134
 135     tss(const tss&) = delete;
 136     tss(tss&&) = delete;
 137     void operator=(const tss&) = delete;
 138     void operator=(tss&&) = delete;
 139 };
 140
 141 } // namespace al
 142
 143 #endif /* AL_THREADS_H */