WebA shared_ptr that points to no object is called a null shared_ptr and shall not be dereferenced. Notice though that an empty shared_ptr is not necessarily a null shared_ptr, and a null shared_ptr is not necessarily an empty shared_ptr. shared_ptr objects replicate a limited pointer functionality by providing access to the object they point to ... Webstd::shared_ptr is a smart pointer that retains shared ownership of an object through a pointer. Several shared_ptr objects may own the same object. The object is destroyed and its memory deallocated when either of the following happens: the last remaining shared_ptr owning the object is destroyed; ; the last remaining shared_ptr owning the object is …

C++11スマートポインタ入門 - Qiita

WebSep 8, 2024 · shared_ptr的引用计数本身是安全且无锁的，但对象的读写则不是，因为 shared_ptr 有两个数据成员（指向被管理对象的指针，和指向控制块的指针），读写操作不能原子化。 Webshared_ptr 和 weak_ptr 都可以从线程中使用，而无需进一步同步。 对于 shared_ptr ，有很多文档(例如cppreference.com或stackoverflow上)。您可以从不同的线程安全地访问指向 … texas thrush

C++11:基于std::unordered_map和共享锁构建线程安全的map - 腾 …

Web对于所有STL容器， std::shared_ptr 和 std::weak_ptr 上的线程安全保证要比橡皮布声明要强，请参阅我的回答。 @ChristianAichinger shared_ptr 和 weak_ptr 的唯一"附加线程安全保证"可以确保多个线程对隐藏引用计数的更改不会引入数据争用。 各个 shared_ptr / weak_ptr 对象没有针对数据争用的特殊保护。 WebApr 2, 2024 · 2.对shared_ptr本身的读写是线程不安全的. 一次读写操作分为两步，改变control block的指针，改变content的指针，而这两步并不属于一个原子操作。. 并发执行时 … WebAug 2, 2024 · Example 1. Whenever possible, use the make_shared function to create a shared_ptr when the memory resource is created for the first time. make_shared is exception-safe. It uses the same call to allocate the memory for the control block and the resource, which reduces the construction overhead. If you don't use make_shared, then … swizzle fish