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ruby--ruby/include/ruby/atomic.h
卜部昌平 63ab2fedc8 include/ruby/atomic.h: add doxygen
Must not be a bad idea to improve documents. [ci skip]
2021-09-15 09:25:23 +09:00

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#ifndef RUBY_ATOMIC_H /*-*-C++-*-vi:se ft=cpp:*/
#define RUBY_ATOMIC_H
/**
* @file
* @author Ruby developers <ruby-core@ruby-lang.org>
* @copyright This file is a part of the programming language Ruby.
* Permission is hereby granted, to either redistribute and/or
* modify this file, provided that the conditions mentioned in the
* file COPYING are met. Consult the file for details.
* @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are
* implementation details. Don't take them as canon. They could
* rapidly appear then vanish. The name (path) of this header file
* is also an implementation detail. Do not expect it to persist
* at the place it is now. Developers are free to move it anywhere
* anytime at will.
* @note To ruby-core: remember that this header can be possibly
* recursively included from extension libraries written in C++.
* Do not expect for instance `__VA_ARGS__` is always available.
* We assume C99 for ruby itself but we don't assume languages of
* extension libraries. They could be written in C++98.
* @brief Atomic operations
*
* Basically, if we could assume either C11 or C++11, these macros are just
* redundant. Sadly we cannot. We have to do them ourselves.
*/
/*
* - RUBY_ATOMIC_CAS, RUBY_ATOMIC_EXCHANGE, RUBY_ATOMIC_FETCH_*:
* return the old value.
* - RUBY_ATOMIC_ADD, RUBY_ATOMIC_SUB, RUBY_ATOMIC_INC, RUBY_ATOMIC_DEC, RUBY_ATOMIC_OR, RUBY_ATOMIC_SET:
* may be void.
*/
#if 0
#elif defined HAVE_GCC_ATOMIC_BUILTINS
typedef unsigned int rb_atomic_t;
# define RUBY_ATOMIC_FETCH_ADD(var, val) __atomic_fetch_add(&(var), (val), __ATOMIC_SEQ_CST)
# define RUBY_ATOMIC_FETCH_SUB(var, val) __atomic_fetch_sub(&(var), (val), __ATOMIC_SEQ_CST)
# define RUBY_ATOMIC_OR(var, val) __atomic_fetch_or(&(var), (val), __ATOMIC_SEQ_CST)
# define RUBY_ATOMIC_EXCHANGE(var, val) __atomic_exchange_n(&(var), (val), __ATOMIC_SEQ_CST)
# define RUBY_ATOMIC_CAS(var, oldval, newval) RB_GNUC_EXTENSION_BLOCK( \
__typeof__(var) oldvaldup = (oldval); /* oldval should not be modified */ \
__atomic_compare_exchange_n(&(var), &oldvaldup, (newval), 0, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST); \
oldvaldup )
# define RUBY_ATOMIC_GENERIC_MACRO 1
#elif defined HAVE_GCC_SYNC_BUILTINS
/* @shyouhei hack to support atomic operations in case of gcc. Gcc
* has its own pseudo-insns to support them. See info, or
* http://gcc.gnu.org/onlinedocs/gcc/Atomic-Builtins.html */
typedef unsigned int rb_atomic_t; /* Anything OK */
# define RUBY_ATOMIC_FETCH_ADD(var, val) __sync_fetch_and_add(&(var), (val))
# define RUBY_ATOMIC_FETCH_SUB(var, val) __sync_fetch_and_sub(&(var), (val))
# define RUBY_ATOMIC_OR(var, val) __sync_fetch_and_or(&(var), (val))
# define RUBY_ATOMIC_EXCHANGE(var, val) __sync_lock_test_and_set(&(var), (val))
# define RUBY_ATOMIC_CAS(var, oldval, newval) __sync_val_compare_and_swap(&(var), (oldval), (newval))
# define RUBY_ATOMIC_GENERIC_MACRO 1
#elif defined _WIN32
#if RBIMPL_COMPILER_SINCE(MSVC, 13, 0, 0)
#pragma intrinsic(_InterlockedOr)
#endif
typedef LONG rb_atomic_t;
# define RUBY_ATOMIC_SET(var, val) InterlockedExchange(&(var), (val))
# define RUBY_ATOMIC_INC(var) InterlockedIncrement(&(var))
# define RUBY_ATOMIC_DEC(var) InterlockedDecrement(&(var))
# define RUBY_ATOMIC_FETCH_ADD(var, val) InterlockedExchangeAdd(&(var), (val))
# define RUBY_ATOMIC_FETCH_SUB(var, val) InterlockedExchangeAdd(&(var), -(LONG)(val))
#if defined __GNUC__
# define RUBY_ATOMIC_OR(var, val) __asm__("lock\n\t" "orl\t%1, %0" : "=m"(var) : "Ir"(val))
#elif RBIMPL_COMPILER_BEFORE(MSVC, 13, 0, 0)
# define RUBY_ATOMIC_OR(var, val) rb_w32_atomic_or(&(var), (val))
static inline void
rb_w32_atomic_or(volatile rb_atomic_t *var, rb_atomic_t val)
{
#ifdef _M_IX86
__asm mov eax, var;
__asm mov ecx, val;
__asm lock or [eax], ecx;
#else
#error unsupported architecture
#endif
}
#else
# define RUBY_ATOMIC_OR(var, val) _InterlockedOr(&(var), (val))
#endif
# define RUBY_ATOMIC_EXCHANGE(var, val) InterlockedExchange(&(var), (val))
# define RUBY_ATOMIC_CAS(var, oldval, newval) InterlockedCompareExchange(&(var), (newval), (oldval))
# if RBIMPL_COMPILER_BEFORE(MSVC, 13, 0, 0)
static inline rb_atomic_t
rb_w32_atomic_cas(volatile rb_atomic_t *var, rb_atomic_t oldval, rb_atomic_t newval)
{
return (rb_atomic_t)InterlockedCompareExchange((PVOID *)var, (PVOID)newval, (PVOID)oldval);
}
# undef RUBY_ATOMIC_CAS
# define RUBY_ATOMIC_CAS(var, oldval, newval) rb_w32_atomic_cas(&(var), (oldval), (newval))
# endif
# ifdef _M_AMD64
# define RUBY_ATOMIC_SIZE_ADD(var, val) InterlockedExchangeAdd64((LONG_LONG *)&(var), (val))
# define RUBY_ATOMIC_SIZE_SUB(var, val) InterlockedExchangeAdd64((LONG_LONG *)&(var), -(LONG)(val))
# define RUBY_ATOMIC_SIZE_INC(var) InterlockedIncrement64(&(var))
# define RUBY_ATOMIC_SIZE_DEC(var) InterlockedDecrement64(&(var))
# define RUBY_ATOMIC_SIZE_EXCHANGE(var, val) InterlockedExchange64(&(var), (val))
# define RUBY_ATOMIC_SIZE_CAS(var, oldval, newval) InterlockedCompareExchange64(&(var), (newval), (oldval))
# else
# define RUBY_ATOMIC_SIZE_ADD(var, val) InterlockedExchangeAdd((LONG *)&(var), (val))
# define RUBY_ATOMIC_SIZE_SUB(var, val) InterlockedExchangeAdd((LONG *)&(var), -(LONG)(val))
# define RUBY_ATOMIC_SIZE_INC(var) InterlockedIncrement((LONG *)&(var))
# define RUBY_ATOMIC_SIZE_DEC(var) InterlockedDecrement((LONG *)&(var))
# define RUBY_ATOMIC_SIZE_EXCHANGE(var, val) InterlockedExchange((LONG *)&(var), (val))
# endif
# ifdef InterlockedExchangePointer
# define RUBY_ATOMIC_PTR_EXCHANGE(var, val) InterlockedExchangePointer((PVOID volatile *)&(var), (PVOID)(val))
# endif /* See below for definitions of other situations */
#elif defined(__sun) && defined(HAVE_ATOMIC_H)
#include <atomic.h>
typedef unsigned int rb_atomic_t;
# define RUBY_ATOMIC_INC(var) atomic_inc_uint(&(var))
# define RUBY_ATOMIC_DEC(var) atomic_dec_uint(&(var))
# define RUBY_ATOMIC_FETCH_ADD(var, val) rb_atomic_fetch_add(&(var), (val))
# define RUBY_ATOMIC_FETCH_SUB(var, val) rb_atomic_fetch_sub(&(var), (val))
# define RUBY_ATOMIC_ADD(var, val) atomic_add_uint(&(var), (val))
# define RUBY_ATOMIC_SUB(var, val) atomic_sub_uint(&(var), (val))
# define RUBY_ATOMIC_OR(var, val) atomic_or_uint(&(var), (val))
# define RUBY_ATOMIC_EXCHANGE(var, val) atomic_swap_uint(&(var), (val))
# define RUBY_ATOMIC_CAS(var, oldval, newval) atomic_cas_uint(&(var), (oldval), (newval))
static inline rb_atomic_t
rb_atomic_fetch_add(volatile rb_atomic_t *var, rb_atomic_t val)
{
return atomic_add_int_nv(var, val) - val;
}
static inline rb_atomic_t
rb_atomic_fetch_sub(volatile rb_atomic_t *var, rb_atomic_t val)
{
return atomic_add_int_nv(var, (rb_atomic_t)(-(int)val)) + val;
}
# if defined(_LP64) || defined(_I32LPx)
# define RUBY_ATOMIC_SIZE_ADD(var, val) atomic_add_long(&(var), (val))
# define RUBY_ATOMIC_SIZE_SUB(var, val) atomic_add_long(&(var), -(val))
# define RUBY_ATOMIC_SIZE_INC(var) atomic_inc_ulong(&(var))
# define RUBY_ATOMIC_SIZE_DEC(var) atomic_dec_ulong(&(var))
# define RUBY_ATOMIC_SIZE_EXCHANGE(var, val) atomic_swap_ulong(&(var), (val))
# define RUBY_ATOMIC_SIZE_CAS(var, oldval, val) atomic_cas_ulong(&(var), (oldval), (val))
# else
# define RUBY_ATOMIC_SIZE_ADD(var, val) atomic_add_int(&(var), (val))
# define RUBY_ATOMIC_SIZE_SUB(var, val) atomic_add_int(&(var), -(val))
# define RUBY_ATOMIC_SIZE_INC(var) atomic_inc_uint(&(var))
# define RUBY_ATOMIC_SIZE_DEC(var) atomic_dec_uint(&(var))
# define RUBY_ATOMIC_SIZE_EXCHANGE(var, val) atomic_swap_uint(&(var), (val))
# endif
#elif defined(__DOXYGEN__)
/**
* Asserts that your environment supports more than one atomic types. These
* days systems tend to have such property (C11 was a standard of decades ago,
* right?) but we still support older ones.
*/
# define RUBY_ATOMIC_GENERIC_MACRO 1
/**
* Type that is eligible for atomic operations. Depending on your host
* platform you might have more than one such type, but we choose one of them
* anyways.
*/
using rb_atomic_t = std::atomic<std::uintptr_t>;
/**
* Atomically replaces the value pointed by `var` with the result of addition
* of `val` to the old value of `var`. In case #RUBY_ATOMIC_GENERIC_MACRO is
* set, this operation could be applied to a signed integer type. However
* there is no portabe way to know what happens on integer overflow on such
* situations. You might better stick to unsigned types.
*
* @param var A variable of ::rb_atomic_t.
* @param val Value to add.
* @return What was stored in `var` before the addition.
* @post `var` holds `var + val`.
*/
# define RUBY_ATOMIC_FETCH_ADD(var, val) std::atomic_fetch_add(&(var), val)
/**
* Atomically replaces the value pointed by `var` with the result of addition
* of `val` to the old value of `var`. In case #RUBY_ATOMIC_GENERIC_MACRO is
* set, this operation could be applied to a signed integer type. However
* there is no portabe way to know what happens on integer overflow on such
* situations. You might better stick to unsigned types.
*
* @param var A variable of ::rb_atomic_t.
* @param val Value to subtract.
* @return What was stored in `var` before the suntraction.
* @post `var` holds `var - val`.
*/
# define RUBY_ATOMIC_FETCH_SUB(var, val) std::atomic_fetch_sub(&(var), val)
/**
* Atomically replaces the value pointed by `var` with the result of
* bitwise OR between `val` and the old value of `var`.
*
* @param var A variable of ::rb_atomic_t.
* @param val Value to mix.
* @return void
* @post `var` holds `var | val`.
* @note For portability, this macro can return void.
*/
# define RUBY_ATOMIC_OR(var, val) (void)std::atomic_fetch_or(&(var), val)
/**
* Atomically replaces the value pointed by `var` with `val`. This is just an
* assignment, but you can additionally know the previous value.
*
* @param var A variable of ::rb_atomic_t.
* @param val Value to set.
* @return What was stored in `var` before the assignment.
* @post `var` holds `val`.
*/
# define RUBY_ATOMIC_EXCHANGE(var, val) std::atomic_exchange(&(var), (val))
/**
* Atomic compare-and-swap. This stores `val` to `var` if and only if the
* assignment changes the value of `var` from `oldval` to `newval`. You can
* detect whether the assignment happened or not using the return value.
*
* @param var A variable of ::rb_atomic_t.
* @param oldval Expected value of `var` before the assignment.
* @param newval What you want to store at `var`.
* @retval 1 Successful assignment.
* @retval 0 Something different from `oldval` resides at `var`.
*/
# define RUBY_ATOMIC_CAS(var, oldval, newval) \
std::atomic_compare_exchange_strong(&(var), (newval), (oldval))
#else
# error No atomic operation found
#endif
/**
* Identical to #RUBY_ATOMIC_EXCHANGE, except for the return type.
*
* @param var A variable of ::rb_atomic_t.
* @param val Value to set.
* @return void
* @post `var` holds `val`.
*/
#ifndef RUBY_ATOMIC_SET
# define RUBY_ATOMIC_SET(var, val) (void)RUBY_ATOMIC_EXCHANGE(var, val)
#endif
/**
* Identical to #RUBY_ATOMIC_FETCH_ADD, except for the return type.
*
* @param var A variable of ::rb_atomic_t.
* @param val Value to add.
* @return void
* @post `var` holds `var + val`.
*/
#ifndef RUBY_ATOMIC_ADD
# define RUBY_ATOMIC_ADD(var, val) (void)RUBY_ATOMIC_FETCH_ADD(var, val)
#endif
/**
* Identical to #RUBY_ATOMIC_FETCH_ADD, except for the return type.
*
* @param var A variable of ::rb_atomic_t.
* @param val Value to subtract.
* @return void
* @post `var` holds `var - val`.
*/
#ifndef RUBY_ATOMIC_SUB
# define RUBY_ATOMIC_SUB(var, val) (void)RUBY_ATOMIC_FETCH_SUB(var, val)
#endif
/**
* Atomically increments the value pointed by `var`.
*
* @param var A variable of ::rb_atomic_t.
* @return void
* @post `var` holds `var + 1`.
*/
#ifndef RUBY_ATOMIC_INC
# define RUBY_ATOMIC_INC(var) RUBY_ATOMIC_ADD(var, 1)
#endif
/**
* Atomically decrements the value pointed by `var`.
*
* @param var A variable of ::rb_atomic_t.
* @return void
* @post `var` holds `var - 1`.
*/
#ifndef RUBY_ATOMIC_DEC
# define RUBY_ATOMIC_DEC(var) RUBY_ATOMIC_SUB(var, 1)
#endif
/**
* Identical to #RUBY_ATOMIC_INC, except it expects its argument is an
* (possibly `_Atomic` qualified) unsigned integer of the same width of
* `size_t`. There are cases where ::rb_atomic_t is 32bit while `size_t` is
* 64bit. This should be used for size related operations to support such
* platforms.
*
* @param var A variable of (possibly _Atomic qualified) `size_t`.
* @return void
* @post `var` holds `var + 1`.
*/
#ifndef RUBY_ATOMIC_SIZE_INC
# define RUBY_ATOMIC_SIZE_INC(var) RUBY_ATOMIC_INC(var)
#endif
/**
* Identical to #RUBY_ATOMIC_DEC, except it expects its argument is an
* (possibly `_Atomic` qualified) unsigned integer of the same width of
* `size_t`. There are cases where ::rb_atomic_t is 32bit while `size_t` is
* 64bit. This should be used for size related operations to support such
* platforms.
*
* @param var A variable of (possibly _Atomic qualified) `size_t`.
* @return void
* @post `var` holds `var - 1`.
*/
#ifndef RUBY_ATOMIC_SIZE_DEC
# define RUBY_ATOMIC_SIZE_DEC(var) RUBY_ATOMIC_DEC(var)
#endif
/**
* Identical to #RUBY_ATOMIC_EXCHANGE, except it expects its arguments are
* (possibly `_Atomic` qualified) unsigned integers of the same width of
* `size_t`. There are cases where ::rb_atomic_t is 32bit while `size_t` is
* 64bit. This should be used for size related operations to support such
* platforms.
*
* @param var A variable of (possibly _Atomic qualified) `size_t`.
* @param val Value to set.
* @return What was stored in `var` before the assignment.
* @post `var` holds `val`.
*/
#ifndef RUBY_ATOMIC_SIZE_EXCHANGE
# define RUBY_ATOMIC_SIZE_EXCHANGE(var, val) RUBY_ATOMIC_EXCHANGE(var, val)
#endif
/**
* Identical to #RUBY_ATOMIC_CAS, except it expects its arguments are (possibly
* `_Atomic` qualified) unsigned integers of the same width of `size_t`. There
* are cases where ::rb_atomic_t is 32bit while `size_t` is 64bit. This should
* be used for size related operations to support such platforms.
*
* @param var A variable of (possibly _Atomic qualified) `size_t`.
* @param oldval Expected value of `var` before the assignment.
* @param val What you want to store at `var`.
* @retval 1 Successful assignment.
* @retval 0 Something different from `oldval` resides at `var`.
*/
#ifndef RUBY_ATOMIC_SIZE_CAS
# define RUBY_ATOMIC_SIZE_CAS(var, oldval, val) RUBY_ATOMIC_CAS(var, oldval, val)
#endif
/**
* Identical to #RUBY_ATOMIC_ADD, except it expects its arguments are (possibly
* `_Atomic` qualified) unsigned integers of the same width of `size_t`. There
* are cases where ::rb_atomic_t is 32bit while `size_t` is 64bit. This should
* be used for size related operations to support such platforms.
*
* @param var A variable of (possibly _Atomic qualified) `size_t`.
* @param val Value to add.
* @return void
* @post `var` holds `var + val`.
*/
#ifndef RUBY_ATOMIC_SIZE_ADD
# define RUBY_ATOMIC_SIZE_ADD(var, val) RUBY_ATOMIC_ADD(var, val)
#endif
/**
* Identical to #RUBY_ATOMIC_SUB, except it expects its arguments are (possibly
* `_Atomic` qualified) unsigned integers of the same width of `size_t`. There
* are cases where ::rb_atomic_t is 32bit while `size_t` is 64bit. This should
* be used for size related operations to support such platforms.
*
* @param var A variable of (possibly _Atomic qualified) `size_t`.
* @param val Value to subtract.
* @return void
* @post `var` holds `var - val`.
*/
#ifndef RUBY_ATOMIC_SIZE_SUB
# define RUBY_ATOMIC_SIZE_SUB(var, val) RUBY_ATOMIC_SUB(var, val)
#endif
#if RUBY_ATOMIC_GENERIC_MACRO
/**
* Identical to #RUBY_ATOMIC_EXCHANGE, except it expects its arguments are
* (possibly `_Atomic` qualified) unsigned integers of the same width of
* `void*`. There are cases where ::rb_atomic_t is 32bit while `void*` is
* 64bit. This should be used for pointer related operations to support such
* platforms.
*
* @param var A variable of (possibly _Atomic qualified) `void *`.
* @param val Value to set.
* @return What was stored in `var` before the assignment.
* @post `var` holds `val`.
*/
# ifndef RUBY_ATOMIC_PTR_EXCHANGE
# define RUBY_ATOMIC_PTR_EXCHANGE(var, val) RUBY_ATOMIC_EXCHANGE(var, val)
# endif
/**
* Identical to #RUBY_ATOMIC_CAS, except it expects its arguments are (possibly
* `_Atomic` qualified) unsigned integers of the same width of `void*`. There
* are cases where ::rb_atomic_t is 32bit while `void*` is 64bit. This should
* be used for size related operations to support such platforms.
*
* @param var A variable of (possibly _Atomic qualified) `void*`.
* @param oldval Expected value of `var` before the assignment.
* @param newval What you want to store at `var`.
* @retval 1 Successful assignment.
* @retval 0 Something different from `oldval` resides at `var`.
*/
# ifndef RUBY_ATOMIC_PTR_CAS
# define RUBY_ATOMIC_PTR_CAS(var, oldval, newval) RUBY_ATOMIC_CAS(var, oldval, newval)
# endif
/**
* Identical to #RUBY_ATOMIC_EXCHANGE, except it expects its arguments are
* ::VALUE. There are cases where ::rb_atomic_t is 32bit while ::VALUE is
* 64bit. This should be used for pointer related operations to support such
* platforms.
*
* @param var A variable of ::VALUE.
* @param val Value to set.
* @return What was stored in `var` before the assignment.
* @post `var` holds `val`.
*/
# ifndef RUBY_ATOMIC_VALUE_EXCHANGE
# define RUBY_ATOMIC_VALUE_EXCHANGE(var, val) RUBY_ATOMIC_EXCHANGE(var, val)
# endif
/**
* Identical to #RUBY_ATOMIC_CAS, except it expects its arguments are (possibly
* `_Atomic` qualified) unsigned integers of the same width of `void*`. There
* are cases where ::rb_atomic_t is 32bit while `void*` is 64bit. This should
* be used for size related operations to support such platforms.
*
* @param var A variable of (possibly _Atomic qualified) `void*`.
* @param oldval Expected value of `var` before the assignment.
* @param val What you want to store at `var`.
* @retval 1 Successful assignment.
* @retval 0 Something different from `oldval` resides at `var`.
*/
# ifndef RUBY_ATOMIC_VALUE_CAS
# define RUBY_ATOMIC_VALUE_CAS(var, oldval, val) RUBY_ATOMIC_CAS(var, oldval, val)
# endif
#endif
#ifndef RUBY_ATOMIC_PTR_EXCHANGE
# if SIZEOF_VOIDP == SIZEOF_SIZE_T
# define RUBY_ATOMIC_PTR_EXCHANGE(var, val) (void *)RUBY_ATOMIC_SIZE_EXCHANGE(*(size_t *)&(var), (size_t)(val))
# else
# error No atomic exchange for void*
# endif
#endif
#ifndef RUBY_ATOMIC_PTR_CAS
# if SIZEOF_VOIDP == SIZEOF_SIZE_T
# define RUBY_ATOMIC_PTR_CAS(var, oldval, val) (void *)RUBY_ATOMIC_SIZE_CAS(*(size_t *)&(var), (size_t)(oldval), (size_t)(val))
# else
# error No atomic compare-and-set for void*
# endif
#endif
#ifndef RUBY_ATOMIC_VALUE_EXCHANGE
# if SIZEOF_VALUE == SIZEOF_SIZE_T
# define RUBY_ATOMIC_VALUE_EXCHANGE(var, val) RUBY_ATOMIC_SIZE_EXCHANGE(*(size_t *)&(var), (size_t)(val))
# else
# error No atomic exchange for VALUE
# endif
#endif
#ifndef RUBY_ATOMIC_VALUE_CAS
# if SIZEOF_VALUE == SIZEOF_SIZE_T
# define RUBY_ATOMIC_VALUE_CAS(var, oldval, val) RUBY_ATOMIC_SIZE_CAS(*(size_t *)&(var), (size_t)(oldval), (size_t)(val))
# else
# error No atomic compare-and-set for VALUE
# endif
#endif
#endif /* RUBY_ATOMIC_H */