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    std::lock

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    <metanoindex/>

     
    C++
     
    Thema Support-Bibliothek
    Threads
    Original:
    Threads
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    thread(C++11)
    this_thread Namespace
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    this_thread namespace
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    get_id(C++11)
    yield(C++11)
    sleep_for(C++11)
    sleep_until(C++11)
    Gegenseitigen Ausschluss
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    Mutual exclusion
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    mutex(C++11)
    timed_mutex(C++11)
    Generische Sperrverwaltung
    Original:
    Generic lock management
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    lock_guard(C++11)
    unique_lock(C++11)
    defer_lock_t
    try_to_lock_t
    adopt_lock_t    		(C++11)
    (C++11)
    (C++11)
    lock(C++11)
    try_lock(C++11)
    defer_lock
    try_to_lock
    adopt_lock    		(C++11)
    (C++11)
    (C++11)
    Zustand Variablen
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    Condition variables
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    condition_variable(C++11)
    condition_variable_any(C++11)
    notify_all_at_thread_exit(C++11)
    cv_status(C++11)
    Futures
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    Futures
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    promise(C++11)
    future(C++11)
    shared_future(C++11)
    packaged_task(C++11)
    async(C++11)
    launch(C++11)
    future_status(C++11)
    future_error(C++11)
    future_category(C++11)
    future_errc(C++11)
     
    <tbody> </tbody>
    definiert in Header <mutex>
    template< class Lockable1, class Lockable2, class LockableN... > void lock( Lockable1& lock1, Lockable2& lock2, LockableN& lockn... );
    		 (seit C++11)
    Sperrt den gegebenen Lockable Objekten lock1, lock2, ..., lockn mit einem Deadlock Vermeidung Algorithmus zur Deadlock zu vermeiden .
    Original:
    Locks the given Lockable objects lock1, lock2, ..., lockn using a deadlock avoidance algorithm to avoid deadlock.
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    Die Objekte werden durch eine unbestimmte Reihe von Aufrufen lock gesperrt, try_lock, unlock. Wenn ein Aufruf an lock oder unlock führt zu einer Ausnahme wird unlock für alle gesperrten Objekte, bevor erneute Auslösen genannt .
    Original:
    The objects are locked by an unspecified series of calls to lock, try_lock, unlock. If a call to lock or unlock results in an exception, unlock is called for any locked objects before rethrowing.
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    Parameter

    lock1, lock2, ... , lockn -
    Die Lockable Objekte zu sperren
    Original:
    the Lockable objects to lock
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    Rückgabewert

    (None)
    Original:
    (none)
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    Beispiel

    Das folgende Beispiel verwendet std::lock auf Paare von Mutexe ohne Stillstand zu sperren .
    Original:
    The following example uses std::lock to lock pairs of mutexes without deadlock.
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    #include <mutex>
#include <thread>
#include <iostream>
#include <vector>
#include <functional>
#include <chrono>

struct Employee {
    Employee(int id) : id(id) {}
    int id;
    std::vector<int> lunch_partners;
    std::mutex m;
};

void send_mail(Employee &e1, Employee &e2)
{
    // simulate a time-consuming messaging operation
    std::this_thread::sleep_for(std::chrono::seconds(1));
}

void assign_lunch_partner(Employee &e1, Employee &e2)
{
    // use std::lock to acquire two locks without worrying about 
    // other calls to assign_lunch_partner deadlocking us
    std::lock(e1.m, e2.m);

    e1.lunch_partners.push_back(e2.id);
    e2.lunch_partners.push_back(e1.id);

    e1.m.unlock();
    e2.m.unlock();

    send_mail(e1, e2);
    send_mail(e2, e1);
}

int main()
{
    Employee alice(0), bob(1), christina(2), dave(3);

    // assign in parallel threads because mailing users about lunch assignments
    // takes a long time
    std::vector<std::thread> threads;
    threads.emplace_back(assign_lunch_partner, std::ref(alice), std::ref(bob));
    threads.emplace_back(assign_lunch_partner, std::ref(christina), std::ref(bob));
    threads.emplace_back(assign_lunch_partner, std::ref(christina), std::ref(alice));
    threads.emplace_back(assign_lunch_partner, std::ref(dave), std::ref(bob));

    for (auto &thread : threads) thread.join();
}


    Siehe auch

    (C++11)
    Versuche, das Eigentum an Mutexe via wiederholten Aufforderungen an try_lock erhalten
    Original:
    attempts to obtain ownership of mutexes via repeated calls to try_lock
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    (Funktions-Template) [edit]