<function>WaitForBackgroundWorkerStartup(<parameter>BackgroundWorkerHandle

*handle</parameter>, <parameter>pid_t *</parameter>)</function> function.

This function will block until the postmaster has attempted to start the

background worker, or until the postmaster dies. If the backgroundrunner

is running, the return value will <literal>BGWH_STARTED</literal>, and

background worker, or until the postmaster dies. If the backgroundworker

is running, the return value willbe<literal>BGWH_STARTED</literal>, and

the PID will be written to the provided address. Otherwise, the return

value will be <literal>BGWH_STOPPED</literal> or

<literal>BGWH_POSTMASTER_DIED</literal>.

</para>

<para>

A process can also wait for a background worker to shut down, by using the

<function>WaitForBackgroundWorkerShutdown(<parameter>BackgroundWorkerHandle

*handle</parameter>)</function> function and passing the

<type>BackgroundWorkerHandle *</type> obtained at registration. This

function will block until the background worker exits, or postmaster dies.

When the background worker exits, the return value is

<literal>BGWH_STOPPED</literal>, if postmaster dies it will return

<literal>BGWH_POSTMASTER_DIED</literal>.

</para>

<para>

If a background worker sends asynchronous notifications with the

<command>NOTIFY</command> command via the Server Programming Interface