Creating Client Sessions

A session creates a single, client connection to a Solace event broker for sending and receiving messages. The Solace Message Format (SMF) is used to facilitate the communication between a client and an event broker, and this SMF communication is then encapsulated through a single TCP connection.

A session can also use a shared memory transport when using the inter‑process communications (IPC) capabilities of the Solace C API; for more information see Configuring Inter-Process Communications. However, shared memory transport and IPC capabilities are not available when using the Solace C API for iOS applications.

By default, sessions are unsecured—in a connected session, the SMF data sent between a client and an event broker is transmitted as plain text. However, it is also possible to establish a secure session that uses Transport Layer Security (TLS)/ Secure Sockets Layer (SSL) protocols so that the SMF data is encrypted. For information on how to configure specific TLS/SSL session properties and establish a secure session, see Creating Secure Sessions.

Sessions are always created within a context. The client application controls whether one or multiple sessions are grouped under a processing context. Once a session is created within a given context, it remains associated with that single context until it is disposed.

To create a session, the client application must provide the following:

  • Session properties

    Properties used to customize the session. Any session property that is not explicitly supplied is set to default values. Although the defaults can be used in many cases, some client and event broker parameters require specific input from the client to establish a connection to a Message VPN on an event broker. See Session Properties Required to Establish a Connection.

  • Session event callback

    For the Solace C API, a session event callback must be specified when creating a session. This callback is invoked for each session event. See Handling Session Events.

  • Message receive callback

    For the Solace C API, a message event callback must be specified when creating a session. This callback is invoked each time a Direct message is received through the session. see Receiving Direct Messages.

Once a session is created, it must be connected using the functions listed below.

To Create a Session

Use solClient_session_create(...).

To Connect a Session

Use solClient_session_connect(...).

To Close a Session

Use the following functions:

  • solClient_session_disconnect(...)
  • solClient_session_destroy(...)
  • Calling destroy to destroy a session object is not required. If the session object is not destroyed, you may reconnect to it at a later time.
  • If a session is destroyed or a global cleanup is performed, any buffered messages associated with that session are discarded before it is disconnected. When a context is destroyed, the buffered messages associated with every session contained within that context are discarded.

Related Samples

For an example of how to create and connect sessions, see the DirectPubSub sample for the Solace C API.