std::defer_lock_t, std::try_to_lock_t, std::adopt_lock_t
Материал из cppreference.com
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| struct defer_lock_t { }; |
(начиная с C++11) | |
| struct try_to_lock_t { }; |
(начиная с C++11) | |
| struct adopt_lock_t { }; |
(начиная с C++11) | |
std::defer_lock_t, std::try_to_lock_t и std::adopt_lock_t пустые структуры типов тегов используется для указания блокировки стратегии std::lock_guard и std::unique_lock.Original:
std::defer_lock_t, std::try_to_lock_t and std::adopt_lock_t are empty struct tag types used to specify locking strategy for std::lock_guard and std::unique_lock.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
| Type
Original: Type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Effect(s) |
defer_lock_t
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не приобретают права собственности на мьютекс
Original: do not acquire ownership of the mutex The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
try_to_lock_t
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попробуйте приобрести в собственность мьютекса без блокирования
Original: try to acquire ownership of the mutex without blocking The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
adopt_lock_t
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Предположим, вызывающий поток уже имеет собственность на мьютекс
Original: assume the calling thread already has ownership of the mutex The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
[править] Пример
#include <mutex> #include <thread> struct bank_account { explicit bank_account(int balance) : balance(balance) {} int balance; std::mutex m; }; void transfer(bank_account &from, bank_account &to, int amount) { // attempt to lock both mutexes without deadlock std::lock(from.m, to.m); // make sure both already-locked mutexes are unlocked when // we're done; if we just used the lock_guard without std::lock // and std::adopt_lock, we might deadlock with other calls to transfer std::lock_guard lock1(from.m, std::adopt_lock); std::lock_guard lock2(to.m, std::adopt_lock); from.balance -= amount; to.balance += amount; } int main() { bank_account my_account(100); bank_account your_account(50); std::thread t1(transfer, my_account, your_account, 10); std::thread t2(transfer, your_account, my_account, 5); t1.join(); t2.join(); }
[править] См. также
| Тег константы используются для определения замок стратегии Original: tag constants used to specify locking strategy The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (константа) | |
| строит lock_guard, необязательно блокировки данного мьютекса Original: constructs a lock_guard, optionally locking the given mutex The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (public функция-член std::lock_guard)
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| строит unique_lock, необязательно блокировки поставляется мьютекс Original: constructs a unique_lock, optionally locking the supplied mutex The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (public функция-член std::unique_lock)
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