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CPG_MODEL_INITIALICorosync Cluster Engine Programmer's CPG_MODEL_INITIALIZE(3)

       cpg_model_initialize - Create a new connection to the CPG service

       #include	<corosync/cpg.h>

       cs_error_t   cpg_model_initialize(cpg_handle_t	*handle,   cpg_model_t
       model, cpg_model_data_t *model_data, void *context);

       The cpg_model_initialize	function is used to initialize a connection to
       the closed process groups API.

       Each application	may have several connections to	the CPG	API.  Each ap-
       plication uses the handle argument to uniquely identify the connection.
       The  handle  argument  is then used in other function calls to identify
       the connection to be used for communication with	the CPG	service.

       Argument	model is used to explicitly choose set of callbacks and	inter-
       nal parameters. Currently only model CPG_MODEL_V1 is defined.

       Callbacks  and  internal	 parameters are	passed by model_data argument.
       This is casted pointer (idea is similar as in sockaddr function)	to one
       of   structures	 corresponding	 to   chosen   model.  Currently  only
       cpg_model_v1_data_t is needed.

       The MODEL_V1 is backwards compatible with original  callbacks  initial-
       ized  by	 cpg_initialize	 but  new callback cpg_totem_confchg_fn	is de-

       Every time an CPG event occurs within the  joined  group,  one  of  the
       callbacks  specified by the argument callbacks is called.  The callback
       functions are described by the following	type definitions:

	      typedef void (*cpg_deliver_fn_t) (
		      cpg_handle_t handle,
		      const struct cpg_name *group_name,
		      uint32_t nodeid,
		      uint32_t pid,
		      const void *msg,
		      size_t msg_len);

	      typedef void (*cpg_confchg_fn_t) (
		      cpg_handle_t handle,
		      const struct cpg_name *group_name,
		      const struct cpg_address *member_list, size_t member_list_entries,
		      const struct cpg_address *left_list, size_t left_list_entries,
		      const struct cpg_address *joined_list, size_t joined_list_entries);

	      typedef void (*cpg_totem_confchg_fn_t) (
		      cpg_handle_t handle,
		      struct cpg_ring_id ring_id,
		      uint32_t member_list_entries,
		      const uint32_t *member_list);

       The cpg_model_v1_data_t structure is defined as:

	      typedef struct {
		      cpg_model_t model;
		      cpg_deliver_fn_t cpg_deliver_fn;
		      cpg_confchg_fn_t cpg_confchg_fn;
		      cpg_totem_confchg_fn_t cpg_totem_confchg_fn;
	      unsigned int flags;
	      }	cpg_model_v1_data_t;

       When a configuration change occurs or a message is to be	delivered  one
       of the callbacks	is called from the cpg_dispatch() function.  If	a con-
       figuration change occurs, cpg_confchg_fn	is called.  If a delivery of a
       message occurs, cpg_deliver_fn is called.  When totem membership	change
       occurs, cpg_totem_confchg_fn is called.	You  can  OR  CPG_MODEL_V1_DE-
       LIVER_INITIAL_TOTEM_CONF	 constant to flags to get callback after first
       confchg event.

       The cpg_address structure is defined

	      struct cpg_address {
		      unsigned int nodeid;
		      unsigned int pid;
		      unsigned int reason;

       where nodeid is a 32 bit	unique node identifier,	pid is the process  ID
       of  the process that has	joined/left the	group or sent the message, and
       reason is an integer code  indicating  why  the	node  joined/left  the

	      CPG_REASON_JOIN	  - the	process	joined a group using cpg_join().
	      CPG_REASON_LEAVE	  - the	process	left a group using cpg_leave()
	      CPG_REASON_NODEDOWN - the	process	left a group because the node left the cluster.
	      CPG_REASON_NODEUP	  - the	process	joined a group because it was already a	member of a group on a node that has just joined the cluster
	      CPG_REASON_PROCDOWN - the	process	left a group without calling cpg_leave()

       The cpg_ring_id structure is defined

	      struct cpg_ring_id {
		      uint32_t nodeid;
		      uint64_t seq;

       where  nodeid is	if of node of current Totem leader and seq is increas-
       ing number.

       This call returns the CS_OK value if successful,	otherwise an error  is

       The errors are undocumented.

       cpg_overview(3),	  cpg_initialize(3),  cpg_finalize(3),	cpg_fd_get(3),
       cpg_dispatch(3),	  cpg_join(3),	 cpg_leave(3),	  cpg_mcast_joined(3),
       cpg_membership_get(3)	      cpg_zcb_alloc(3)	       cpg_zcb_free(3)
       cpg_zcb_mcast_joined(3) cpg_context_get(3)  cpg_context_set(3)  cpg_lo-
       cal_get(3) cpg_model_initialize(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		  2010-04-07	       CPG_MODEL_INITIALIZE(3)


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