SAM_HC_CALLBACK_REGISTER(3)			    Corosync Cluster Engine Programmer's Manual 		       SAM_HC_CALLBACK_REGISTER(3)

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  abnor-
       mally.  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.

SEE ALSO

       sam_start(3), sam_stop(3), sam_hc_send(3), sam_register(3),

       CS_ERR_TRY_AGAIN Resource temporarily unavailable

       CS_ERR_INVALID_PARAM Invalid argument

       CS_ERR_ACCESS Permission denied

       CS_ERR_LIBRARY The connection failed

       CS_ERR_INTERRUPT System call inturrupted by a signal

       CS_ERR_NOT_SUPPORTED The requested protocol/functuality not supported

       CS_ERR_MESSAGE_ERROR Incorrect auth message received

       CS_ERR_NO_MEMORY Not enough memory to completed the requested task

corosync Man Page						    12/01/2009					       SAM_HC_CALLBACK_REGISTER(3)