pmdadaemon(3) — Linux manual page


PMDADAEMON(3)           Library Functions Manual           PMDADAEMON(3)

NAME         top

       pmdaDaemon - initialize the PMDA to run as a daemon

C SYNOPSIS         top

       #include <pcp/pmapi.h>
       #include <pcp/pmda.h>

       void pmdaDaemon(pmdaInterface *dispatch, int interface, const
               char *name, int domain, const char *logfile, const
               char *helptext);

       cc ... -lpcp_pmda -lpcp

DESCRIPTION         top

       pmdaDaemon initializes the pmdaInterface structure to use the
       interface extensions assuming the PMDA(3) is to be run as a
       daemon.  The pmdaInterface structure is initialized with:

       name   The name of the agent.

       domain The default domain number of the agent which uniquely
              identifies this PMDA from other running PMDAs.  This may
              be subsequently changed by a command line option -d (see

              The default path to the log file.  This may be replaced by
              the -l command line option if using pmdaGetOpt.  logfile
              will be copied with strdup(3), so the storage associated
              with logfile may be released after the call to pmdaDaemon.

              The default path to the help text (see pmdaText(3).  This
              may be replaced by the -h command line option if using
              pmdaGetOpt(3).  If no help text is installed, or you are
              not using pmdaText(3), then this should be set to NULL,
              otherwise helptext will be copied with strdup(3), so the
              storage associated with helptext may be released after the
              call to pmdaDaemon.

       The callbacks are initialized to pmdaProfile(3), pmdaFetch(3),
       pmdaDesc(3), pmdaText(3), pmdaInstance(3) and pmdaStore(3).

CAVEAT         top

       The PMDA must be using PMDA_INTERFACE_2 or later.

       Once pmdaDaemon has been called, it is expected that the
       pmdaInterface structure pointed to by dispatch will remain
       accessible to the routines in libpcp_pmda (not reclaimed off the
       stack, not freed or oherwise released, etc.).  If the caller
       needs to move or relocate the pmdaInterface structure for any
       reason, then after the move pmdaInterfaceMoved(3) must be called
       to resestablish the internal integrity of the pmdaInterface
       structure at the new location before any other routine in
       libpcp_pmda is called.

DIAGNOSTICS         top

       Unable to allocate memory for pmdaExt structure
              In addition, the dispatch->status field is set to a value
              less than zero.

       PMDA interface version interface not supported
              The interface version is not supported by pmdaDaemon.

SEE ALSO         top

       PMAPI(3), PMDA(3), pmdaDSO(3), pmdaGetOpt(3),
       pmdaInterfaceMoved(3) and pmdaText(3).

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, send it to  This page was obtained from the
       project's upstream Git repository
       ⟨⟩ on 2023-12-22.
       (At that time, the date of the most recent commit that was found
       in the repository was 2023-12-16.)  If you discover any rendering
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       (which is not part of the original manual page), send a mail to

Performance Co-Pilot               PCP                     PMDADAEMON(3)

Pages that refer to this page: pmda(3)pmdaattribute(3)pmdachildren(3)pmdaconnect(3)pmdadesc(3)pmdadso(3)pmdafetch(3)pmdagetoptions(3)pmdahelp(3)pmdainit(3)pmdainstance(3)pmdainterfacemoved(3)pmdalabel(3)pmdaname(3)pmdaopenlog(3)pmdapmid(3)pmdaprofile(3)pmdastore(3)pmdatext(3)