DB_ENV->set_isalive()

#include <db.h>

int
DB_ENV->set_isalive(DB_ENV *dbenv, int (*is_alive)(DB_ENV *dbenv, 
    pid_t pid, db_threadid_t tid, u_int32_t flags));

Declare a function that returns if a thread of control (either a true thread or a process) is still running. The DB_ENV->set_isalive() method supports the DB_ENV->failchk() method. For more information, see Architecting Data Store and Concurrent Data Store applications, and Architecting Transactional Data Store applications, both in the Berkeley DB Programmer's Reference Guide.

The DB_ENV->set_isalive() method configures operations performed using the specified DB_ENV handle, not all operations performed on the underlying database environment.

The DB_ENV->set_isalive() method may be called at any time during the life of the application.

The DB_ENV->set_isalive() method returns a non-zero error value on failure and 0 on success.

Parameters

is_alive

The is_alive parameter is a function which returns non-zero if the thread of control, identified by the pid and tid arguments, is still running. The function takes four arguments:

dbenv

The dbenv parameter is the enclosing database environment handle, allowing application access to the application-private fields of that object.
pid

The pid parameter is a process ID returned by the function specified to the DB_ENV->set_thread_id() method.
tid

The tid parameter is a thread ID returned by the function specified to the DB_ENV->set_thread_id() method.
flags

The flags parameter must be set to 0 or the following value:
- DB_MUTEX_PROCESS_ONLY
  
  Return only if the process is alive, the thread ID should be ignored.

Errors

The DB_ENV->set_isalive() method may fail and return one of the following non-zero errors:

EINVAL

An invalid flag value or parameter was specified.

Class

DB_ENV