mongocxx::pool Class Reference

A pool of client objects associated with a MongoDB deployment. More...

#include <pool.hpp>

Public Types
using	entry = std::unique_ptr< client, std::function< void(client *)>>
	An entry is a handle on a client object acquired via the pool. More...

Public Member Functions
	pool (const uri &mongodb_uri=mongocxx::uri(), const options::pool &options=options::pool())
	Creates a pool associated with a connection string. More...
	~pool ()
	Destroys a pool.
entry	acquire ()
	Acquires a client from the pool. More...
stdx::optional< entry >	try_acquire ()
	Acquires a client from the pool. More...

Detailed Description

A pool of client objects associated with a MongoDB deployment.

For interoperability with other MongoDB drivers, the minimum and maximum number of connections in the pool is configured using the 'minPoolSize' and 'maxPoolSize' connection string options.

See also

https://docs.mongodb.com/master/reference/connection-string/#connection-string-options

Remarks

When connecting to a replica set, it is much more efficient to use a pool as opposed to manually constructing client objects. The pool will use a single background thread used to monitor the topology of the replica set that is shared between all the client objects it creates. Each standalone client, however, will start its own background thread, leading to many redundant threads and network operations.

As a client is not thread safe, the pool should be preferred in multithreaded programs as it can safely be shared across threads.

Member Typedef Documentation

using mongocxx::pool::entry = std::unique_ptr<client, std::function<void (client*)>>

An entry is a handle on a client object acquired via the pool.

Note

The lifetime of any entry object must be a subset of the pool object from which it was acquired.

Constructor & Destructor Documentation

mongocxx::pool::pool ( const uri &  mongodb_uri = mongocxx::uri(), const options::pool &  options = options::pool()  )

explicit

Creates a pool associated with a connection string.

Parameters

mongodb_uri	A MongoDB URI representing the connection parameters
options	Options to use when connecting to the MongoDB deployment.

Exceptions

mongocxx::exception

if invalid options are provided (whether from the URI or provided client options).

Member Function Documentation

entry mongocxx::pool::acquire

(

)

Acquires a client from the pool.

The calling thread will block until a connection is available.

stdx::optional<entry> mongocxx::pool::try_acquire

(

)

Acquires a client from the pool.

This method will return immediately, but may return a disengaged optional if a client is not available.

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The documentation for this class was generated from the following file:

• src/mongocxx/pool.hpp