test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: libcpp-has-no-threads, c++98, c++03, c++11, c++14

// <atomic>

// static constexpr bool is_always_lock_free;

#include <atomic>
#include <cassert>

#if !defined(__cpp_lib_atomic_is_always_lock_free)
# error Feature test macro missing.
#endif

template <typename T> void checkAlwaysLockFree() {
  if (std::atomic<T>::is_always_lock_free)
    assert(std::atomic<T>().is_lock_free());
}

int main()
{
// structs and unions can't be defined in the template invocation.
// Work around this with a typedef.
#define CHECK_ALWAYS_LOCK_FREE(T)                                              \
  do {                                                                         \
    typedef T type;                                                            \
    checkAlwaysLockFree<type>();                                               \
  } while (0)

    CHECK_ALWAYS_LOCK_FREE(bool);
    CHECK_ALWAYS_LOCK_FREE(char);
    CHECK_ALWAYS_LOCK_FREE(signed char);
    CHECK_ALWAYS_LOCK_FREE(unsigned char);
    CHECK_ALWAYS_LOCK_FREE(char16_t);
    CHECK_ALWAYS_LOCK_FREE(char32_t);
    CHECK_ALWAYS_LOCK_FREE(wchar_t);
    CHECK_ALWAYS_LOCK_FREE(short);
    CHECK_ALWAYS_LOCK_FREE(unsigned short);
    CHECK_ALWAYS_LOCK_FREE(int);
    CHECK_ALWAYS_LOCK_FREE(unsigned int);
    CHECK_ALWAYS_LOCK_FREE(long);
    CHECK_ALWAYS_LOCK_FREE(unsigned long);
    CHECK_ALWAYS_LOCK_FREE(long long);
    CHECK_ALWAYS_LOCK_FREE(unsigned long long);
    CHECK_ALWAYS_LOCK_FREE(std::nullptr_t);
    CHECK_ALWAYS_LOCK_FREE(void*);
    CHECK_ALWAYS_LOCK_FREE(float);
    CHECK_ALWAYS_LOCK_FREE(double);
    CHECK_ALWAYS_LOCK_FREE(long double);
    CHECK_ALWAYS_LOCK_FREE(int __attribute__((vector_size(1 * sizeof(int)))));
    CHECK_ALWAYS_LOCK_FREE(int __attribute__((vector_size(2 * sizeof(int)))));
    CHECK_ALWAYS_LOCK_FREE(int __attribute__((vector_size(4 * sizeof(int)))));
    CHECK_ALWAYS_LOCK_FREE(int __attribute__((vector_size(16 * sizeof(int)))));
    CHECK_ALWAYS_LOCK_FREE(int __attribute__((vector_size(32 * sizeof(int)))));
    CHECK_ALWAYS_LOCK_FREE(float __attribute__((vector_size(1 * sizeof(float)))));
    CHECK_ALWAYS_LOCK_FREE(float __attribute__((vector_size(2 * sizeof(float)))));
    CHECK_ALWAYS_LOCK_FREE(float __attribute__((vector_size(4 * sizeof(float)))));
    CHECK_ALWAYS_LOCK_FREE(float __attribute__((vector_size(16 * sizeof(float)))));
    CHECK_ALWAYS_LOCK_FREE(float __attribute__((vector_size(32 * sizeof(float)))));
    CHECK_ALWAYS_LOCK_FREE(double __attribute__((vector_size(1 * sizeof(double)))));
    CHECK_ALWAYS_LOCK_FREE(double __attribute__((vector_size(2 * sizeof(double)))));
    CHECK_ALWAYS_LOCK_FREE(double __attribute__((vector_size(4 * sizeof(double)))));
    CHECK_ALWAYS_LOCK_FREE(double __attribute__((vector_size(16 * sizeof(double)))));
    CHECK_ALWAYS_LOCK_FREE(double __attribute__((vector_size(32 * sizeof(double)))));
    CHECK_ALWAYS_LOCK_FREE(struct{});
    CHECK_ALWAYS_LOCK_FREE(struct{ int i; });
    CHECK_ALWAYS_LOCK_FREE(struct{ int i[2]; });
    CHECK_ALWAYS_LOCK_FREE(struct{ long long int i[2]; });
    CHECK_ALWAYS_LOCK_FREE(struct{ long long int i[4]; });
    CHECK_ALWAYS_LOCK_FREE(struct{ long long int i[8]; });
    CHECK_ALWAYS_LOCK_FREE(struct{ long long int i[16]; });
    CHECK_ALWAYS_LOCK_FREE(struct{ char c; /* padding */ long long int i; });
    CHECK_ALWAYS_LOCK_FREE(union{ int i; float f; });

    // C macro and static constexpr must be consistent.
    static_assert(std::atomic<bool>::is_always_lock_free == (2 == ATOMIC_BOOL_LOCK_FREE));
    static_assert(std::atomic<char>::is_always_lock_free == (2 == ATOMIC_CHAR_LOCK_FREE));
    static_assert(std::atomic<signed char>::is_always_lock_free == (2 == ATOMIC_CHAR_LOCK_FREE));
    static_assert(std::atomic<unsigned char>::is_always_lock_free == (2 == ATOMIC_CHAR_LOCK_FREE));
    static_assert(std::atomic<char16_t>::is_always_lock_free == (2 == ATOMIC_CHAR16_T_LOCK_FREE));
    static_assert(std::atomic<char32_t>::is_always_lock_free == (2 == ATOMIC_CHAR32_T_LOCK_FREE));
    static_assert(std::atomic<wchar_t>::is_always_lock_free == (2 == ATOMIC_WCHAR_T_LOCK_FREE));
    static_assert(std::atomic<short>::is_always_lock_free == (2 == ATOMIC_SHORT_LOCK_FREE));
    static_assert(std::atomic<unsigned short>::is_always_lock_free == (2 == ATOMIC_SHORT_LOCK_FREE));
    static_assert(std::atomic<int>::is_always_lock_free == (2 == ATOMIC_INT_LOCK_FREE));
    static_assert(std::atomic<unsigned int>::is_always_lock_free == (2 == ATOMIC_INT_LOCK_FREE));
    static_assert(std::atomic<long>::is_always_lock_free == (2 == ATOMIC_LONG_LOCK_FREE));
    static_assert(std::atomic<unsigned long>::is_always_lock_free == (2 == ATOMIC_LONG_LOCK_FREE));
    static_assert(std::atomic<long long>::is_always_lock_free == (2 == ATOMIC_LLONG_LOCK_FREE));
    static_assert(std::atomic<unsigned long long>::is_always_lock_free == (2 == ATOMIC_LLONG_LOCK_FREE));
    static_assert(std::atomic<void*>::is_always_lock_free == (2 == ATOMIC_POINTER_LOCK_FREE));
    static_assert(std::atomic<std::nullptr_t>::is_always_lock_free == (2 == ATOMIC_POINTER_LOCK_FREE));
}