std::unique_lock<Mutex>::lock
來自 cppreference.com
< cpp | thread | unique lock
| void lock(); |
(C++11 起) | |
鎖定（即，獲取關聯互斥體的所有權）。實質上呼叫 mutex()->lock()。
目錄 |
[編輯] 引數
(無)
[編輯] 返回值
(無)
[編輯] 異常
- 任何由 mutex()->lock() 丟擲的異常。
- 如果沒有關聯的互斥體，則丟擲 std::system_error，錯誤程式碼為 std::errc::operation_not_permitted。
- 如果互斥體已被此
unique_lock鎖定（換句話說，owns_lock() 為 true），則丟擲 std::system_error，錯誤程式碼為 std::errc::resource_deadlock_would_occur。
[編輯] 示例
以下示例使用 lock 重新獲取已解鎖的互斥體。
執行此程式碼
#include <chrono> #include <iostream> #include <mutex> #include <thread> #include <vector> int main() { int counter = 0; std::mutex counter_mutex; std::vector<std::thread> threads; auto worker_task = [&](int id) { std::unique_lock<std::mutex> lock(counter_mutex); ++counter; std::cout << id << ", initial counter: " << counter << '\n'; lock.unlock(); // don't hold the lock while we simulate an expensive operation std::this_thread::sleep_for(std::chrono::seconds(1)); lock.lock(); ++counter; std::cout << id << ", final counter: " << counter << '\n'; }; for (int i = 0; i < 10; ++i) threads.emplace_back(worker_task, i); for (auto& thread : threads) thread.join(); }
可能的輸出
0, initial counter: 1 1, initial counter: 2 2, initial counter: 3 3, initial counter: 4 4, initial counter: 5 5, initial counter: 6 6, initial counter: 7 7, initial counter: 8 8, initial counter: 9 9, initial counter: 10 6, final counter: 11 3, final counter: 12 4, final counter: 13 2, final counter: 14 5, final counter: 15 0, final counter: 16 1, final counter: 17 7, final counter: 18 9, final counter: 19 8, final counter: 20
[編輯] 參閱
| 嘗試鎖定（即獲取）關聯的互斥量而不阻塞 (public member function) | |
| 解鎖（即釋放）關聯的互斥量 (public member function) |
