MongoDB Python和C ++客户端-多个实例出错 [英] MongoDB Python and C++ clients - error with multiple instances

问题描述

我还是MongoDB的新手.我的测试C ++应用程序由许多目标文件组成，其中两个拥有自己的MongoDB实例.我发现这是一个错误，因为我有一个例外:

I'm still new to the MongoDB. My test C++ application is composed from a number of object files, and two of them have their own MongoDB instances. I've found that was a mistake, cause I've got an exception:

terminate called after throwing an instance of 'mongocxx::v_noabi::logic_error'
  what():  cannot create a mongocxx::instance object if one has already been created
Aborted (core dumped)

因此，我将尝试在此应用程序中定义一个MongoDB实例.

So, I'll try to define a single MongoDB instance in this application.

现在我担心我的另一个应用程序-它是Python中的顶级程序，该程序加载许多用C ++编写并具有自己的MongoDB实例的动态库.我应该在哪里定义MongoDB实例-在顶层代码中，在每个库中，在一个库中?

And now I worry about my another application - it's top-level program in Python, which loads a number of dynamic libraries, written in C++ and having their own MongoDB instances. Where should I define the MongoDB instance - in the top-level code, in each library, in one of the libraries?

推荐答案

您应该创建一个共享库，该共享库管理mongocxx::instance的单例实例，并使所有其他需要使用驱动程序的库通过一些驱动程序访问该单例.通用API.请参阅 instance管理示例.

You should create one shared library which manages a singleton instance of mongocxx::instance and have all of the other libraries which need to use the driver access that singleton via some common API. Please see the instance management example.

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