PMDADAEMON(3)

NAME
pmdaDaemon - initialize the PMDA to run as a daemon

C SYNOPSIS
#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
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 pmdaGetOpt(3)).

logfile
    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.

helptext
    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
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 otherwise 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 re-establish the internal integrity of the pmdaInterface structure at the new location before any other routine in libpcp_pmda is called.

DIAGNOSTICS

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