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 regularly 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.

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 interrupted by a signal

       CS_ERR_NOT_SUPPORTED The requested protocol/functionality not supported

       CS_ERR_MESSAGE_ERROR Incorrect auth message received

       CS_ERR_NO_MEMORY Not enough memory to complete the requested task

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