std::shared_timed_mutex::try_lock_for
STD：：共享[医]定时[医]互斥：：尝试[医]锁[医]为
| template< class Rep, class Period > bool try_lock_for( const std::chrono::duration | | (since C++14) |
|---|
试图锁定互斥体。块，直到指定timeout_duration已过或已取得锁，以第一位为准。关于成功锁定获取返回true，否则返回false...
如果timeout_duration小于或等于timeout_duration.zero()，该函数的行为类似于try_lock()...
用一个稳定的时钟来测量持续时间。此函数的阻塞时间可能超过timeout_duration由于调度或资源争用延迟。
和...一样try_lock()，则允许此函数伪造失败并返回。false期间，即使互斥锁没有被任何其他线程锁定。timeout_duration...
优先unlock()对同一个互斥体的操作同步性中定义的28名ASstd::memory_order%29如果返回此操作true...
如果try_lock_for由已经拥有mutex在任何模式%28共享或独占%29中，行为都是未定义的。
参数
| timeout_duration | - | maximum duration to block for |
|---|
返回值
true如果成功获取锁，则为false...
例外
任何由时钟、时间引发的异常[医]在执行%28时钟、时间点和标准库提供的持续时间期间，不要抛出%29。
例
二次
#include <iostream>
#include <mutex>
#include <thread>
#include <vector>
#include <sstream>
std::mutex cout_mutex; // control access to std::cout
std::timed_mutex mutex;
void job(int id)
{
using Ms = std::chrono::milliseconds;
std::ostringstream stream;
for (int i = 0; i < 3; ++i) {
if (mutex.try_lock_for(Ms(100))) {
stream << "success ";
std::this_thread::sleep_for(Ms(100)
mutex.unlock(
} else {
stream << "failed ";
}
std::this_thread::sleep_for(Ms(100)
}
std::lock_guard<std::mutex> lock(cout_mutex
std::cout << "[" << id << "] " << stream.str() << "\n";
}
int main()
{
std::vector<std::thread> threads;
for (int i = 0; i < 4; ++i) {
threads.emplace_back(job, i
}
for (auto& i: threads) {
i.join(
}
}
二次
可能的产出：
二次
[0] failed failed failed
[3] failed failed success
[2] failed success failed
[1] success failed success
二次
另见
| lock | locks the mutex, blocks if the mutex is not available (public member function) |
|---|---|
| try_lock | tries to lock the mutex, returns if the mutex is not available (public member function) |
| try_lock_until | tries to lock the mutex, returns if the mutex has beenunavailable until specified time point has been reached (public member function) |
| unlock | unlocks the mutex (public member function) |
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