SAM_HC_CALLBACK_REGISTER - Online Linux Manual Page

Section : 3
Updated : 12/01/2009
Source : corosync Man Page
Note : Corosync Cluster Engine Programmer's Manual

NAME

sam_hc_callback_register − Register health check callback

SYNOPSIS

#include <corosync/sam.h>

cs_error_t sam_hc_callback_register (sam_hc_callback_t cb);

DESCRIPTION

The sam_hc_callback_register

function is used to register a user provided healthcheck callback. After calling of this function, the SAM is switched from application driven healthchecking to event driven healthchecking. In this mode,

sam_hc_send(3)

does not need to be executed.

The parameter cb

is callback function of type

sam_hc_callback_t

defined as:

typedef int (*sam_hc_callback_t)(void);

This function will be regulargly called and must return 0 if the process is functioning normally, or -1 if the process is executing abnormally. When -1 is returned, the SAM server execute the registered recovery policy.

A value of NULL can be passed into this function to switch into application driven healthchecking. cb

to NULL.

RETURN VALUE

This call return CS_OK value if successful, otherwise and error is returned.

ERRORS

CS_ERR_BAD_HANDLE SAM was not initialized and registered or health checking is in running state

CS_ERR_LIBRARY internal library call failed. This can occur during fork() or pipe () system calls and the errno variable can be read to retrieve more information.