std::atomic_exchange, std::atomic_exchange_explicit

 

C++

Idioma

Conceptos

Utilidades de la biblioteca

Strings biblioteca

Contenedores biblioteca

Algoritmos biblioteca

Los iteradores biblioteca

Numéricos biblioteca

Entrada / salida de la biblioteca

Localizaciones biblioteca

Expresiones biblioteca Regular (C++11)

Operaciones de biblioteca Atómica (C++11)

Tema Biblioteca de ayuda (C++11)

 

Operaciones de biblioteca Atómica

Tipos Original: Types The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

atomic (C++11)

atomic_is_lock_free (C++11)

Funciones Original: Functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

atomic_store atomic_store_explicit (C++11) (C++11)

atomic_load atomic_load_explicit (C++11) (C++11)

atomic_exchange atomic_exchange_explicit (C++11) (C++11)

atomic_compare_exchange_weak atomic_compare_exchange_weak_explicit atomic_compare_exchange_strong atomic_compare_exchange_strong_explicit (C++11) (C++11) (C++11) (C++11)

atomic_fetch_add atomic_fetch_add_explicit (C++11) (C++11)

atomic_fetch_sub atomic_fetch_sub_explicit (C++11) (C++11)

atomic_fetch_and atomic_fetch_and_explicit (C++11) (C++11)

atomic_fetch_or atomic_fetch_or_explicit (C++11) (C++11)

atomic_fetch_xor atomic_fetch_xor_explicit (C++11) (C++11)

Banderas atómicas Original: Atomic flags The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

atomic_flag (C++11)

atomic_flag_test_and_set atomic_flag_test_and_set_explicit (C++11) (C++11)

atomic_flag_clear atomic_flag_clear_explicit (C++11) (C++11)

Inicialización Original: Initialization The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

atomic_init (C++11)

ATOMIC_VAR_INIT (C++11)

ATOMIC_FLAG_INIT (C++11)

Memoria pedido Original: Memory ordering The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

memory_order (C++11)

kill_dependency (C++11)

atomic_thread_fence (C++11)

atomic_signal_fence (C++11)

 

Defined in header <atomic>
template< class T > T atomic_exchange( std::atomic<T>* obj, T desr );	(1)	(ya que C + +11)
template< class T > T atomic_exchange( volatile std::atomic<T>* obj, T desr );	(2)	(ya que C + +11)
template< class T > T atomic_exchange_explicit( std::atomic<T>* obj, T desr,                             std::memory_order order );	(3)	(ya que C + +11)
template< class T > T atomic_exchange_explicit( volatile std::atomic<T>* obj, T desr,                             std::memory_order order );	(4)	(ya que C + +11)

1-2)

Atómicamente sustituye el valor apuntado por obj con el valor de desr y devuelve el valor contenido obj anteriormente, como por obj->exhange(desr)

Original:

Atomically replaces the value pointed to by obj with the value of desr and returns the value obj held previously, as if by obj->exhange(desr)

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

3-4)

Atómicamente sustituye el valor apuntado por obj con el valor de desr y devuelve el valor contenido obj anteriormente, como por obj->exhange(desr, order)

Original:

Atomically replaces the value pointed to by obj with the value of desr and returns the value obj held previously, as if by obj->exhange(desr, order)

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Parámetros

obj	-	puntero al objeto atómico modificar Original: pointer to the atomic object to modify The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
desr	-	el valor a almacenar en el objeto atómico Original: the value to store in the atomic object The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
order	-	sycnhronization la memoria de pedidos para esta operación: todos los valores están permitidos . Original: the memory sycnhronization ordering for this operation: all values are permitted. The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

Valor de retorno

El valor retenido previamente por el objeto al que apunta atómica obj

Original:

The value held previously by the atomic object pointed to by obj

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Excepciones

noexcept specification:  

noexcept

  (ya que C + +11)

Ejemplo

Un mutex spinlock puede ser implementado en el espacio de usuario utilizando una operación de intercambio atómico, similar a atomic_flag_test_and_set

Original:

A spinlock mutex can be implemented in userspace using an atomic exchange operation, similar to atomic_flag_test_and_set

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

#include <thread>
#include <vector>
#include <iostream>
#include <atomic>
 
std::atomic<bool> lock = ATOMIC_VAR_INIT(false);
 
void f(int n)
{
    for(int cnt = 0; cnt < 100; ++cnt) {
        while(std::atomic_exchange_explicit(&lock, true, std::memory_order_acquire))
             ; // spin until acquired
        std::cout << "Output from thread " << n << '\n';
        std::atomic_store_explicit(&lock, false, std::memory_order_release);
    }
}
int main()
{
    std::vector<std::thread> v;
    for (int n = 0; n < 10; ++n) {
        v.emplace_back(f, n);
    }
    for (auto& t : v) {
        t.join();
    }
}

Output:

Output from thread 2
Output from thread 6
Output from thread 7
...<exactly 1000 lines>...

Ver también

exchange (C++11)	automáticamente reemplazado el valor del objeto atómico y obtiene el valor que tenía antes Original: atomically replaced the value of the atomic object and obtains the value held previously The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (miembro público of std::atomic función)
atomic_compare_exchange_weak atomic_compare_exchange_weak_explicit atomic_compare_exchange_strong atomic_compare_exchange_strong_explicit (C++11) (C++11) (C++11) (C++11)	atómicamente compara el valor del objeto atómica con no atómica argumento y realiza intercambio atómico si carga igual o atómica si no Original: atomically compares the value of the atomic object with non-atomic argument and performs atomic exchange if equal or atomic load if not The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (función de plantilla)
std::atomic_exchange(std::shared_ptr) std::atomic_exchange_explicit(std::shared_ptr)	se especializa operaciones atómicas para std::shared_ptr Original: specializes atomic operations for std::shared_ptr The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (función de plantilla)
C documentation for atomic_exchange, atomic_exchange_explicit