# 18.2.369. MPI_T_pvar_session_free

MPI_T_pvar_session_create, MPI_T_pvar_session_free - Create/free performance variable session

## 18.2.369.1. SYNTAX

### 18.2.369.1.1. C Syntax

    #include <mpi.h>

    int MPI_T_pvar_session_create(MPI_T_pvar_session *session)

    int MPI_T_pvar_session_free(MPI_T_pvar_session *session)

## 18.2.369.2. DESCRIPTION

MPI_T_pvar_session_create creates a session for accessing performance variables. The new session is returned in the session parameter.

MPI_T_pvar_session_free releases a session allocated by MPI_T_pvar_session_create and sets the session parameter to MPI_T_PVAR_SESSION_NULL.

## 18.2.369.3. ERRORS

MPI_T_pvar_session_create will fail if:

- `MPI_T_ERR_NOT_INITIALIZED`: The MPI Tools interface not initialized

- `MPI_T_ERR_MEMORY`: Out of memory

- `MPI_T_ERR_OUT_OF_SESSIONS`: No more sessions available

MPI_T_pvar_session_free will fail if:

- `MPI_T_ERR_NOT_INITIALIZED`: The MPI Tools interface not initialized

- `MPI_T_ERR_INVALID_SESSION`: The session parameter is not a valid session