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

NAME

       evs_join - Multicast a message to selected groups

SYNOPSIS

       #include <sys/uio.h> #include <corosync/evs.h>

       int  evs_mcast_groups(evs_handle_t  handle,  evs_guraantee_t  guarantee,  evs_group_t  *groups, int group_entries, struct iovec *iovec, int
       iov_len);

DESCRIPTION

       The evs_mcast_groups(3) function multicasts a message to all the groups specified in the arguemnt groups.  Messages are	delivered  to  all
       processors in the system that are described by the current configuration.

       The argument handle describes a handle created with evs_initialize(3).

       The argument guarantee requests a delivery guarantee for the message to be sent.  The evs_guarantee_t type is defined by:

	      typedef enum {
		  EVS_TYPE_UNORDERED,	    /* not implemented */
		  EVS_TYPE_FIFO,	  /* same as agreed */
		  EVS_TYPE_AGREED,	    /* implemented */
		  EVS_TYPE_SAFE 	  /* not implemented */
	      } evs_guarantee_t;

       The meanings of the evs_guarantee_t typedef are:

       EVS_GUARANTEE_UNORDERED
	      Messages are guaranteed to be delivered, but with no particular order.  This mode is unimplemented in the EVS library.

       EVS_GUARANTEE_FIFO
	      Messages	are  guaranteed  to be delivered in first sent first delivery order from one one.  In fact, this guarantee is actually the
	      AGREED guarantee.

       EVS_GUARANTEE_AGREED
	      All processors must agree on the order of delivery.  If a message is sent from two or more processors at about the  same	time,  the
	      delivery will occur in the same order to all processors.

       EVS_GUARANTEE_SAFE
	      All  processors  must  agree  on	the order of delivery.	Further all processors must have a copy of the message before any delivery
	      takes place.  This mode is unimplemented in the EVS library.

       The groups argument is of the type evs_group_t which is defined by the structure:

	      typedef struct {
		  char key[32];
	      } evs_groups_t;

       The group_entries argument describes the number of entries in the group argument.

       The iovec argument describes the scatter/gather list which is used to transmit a message.  This is a standard  socket  structure  described
       by:

	      struct iovec
	      {
		  void *iov_base;     /* Pointer to data.  */
		  unsigned int iov_len;     /* Length of data.	*/
	      };

       The iovlen argument describes the number of entires in the iovec argument.

RETURN VALUE

       This call returns the EVS_OK value if successful, otherwise an error is returned.

ERRORS

       The errors are undocumented.

SEE ALSO

       evs_overview(8),  evs_initialize(3),  evs_finalize(3),  evs_fd_get(3),  evs_dispatch(3),  evs_leave(3),	evs_join(3),  evs_mcast_joined(3),
       evs_mmembership_get(3) evs_context_get(3) evs_context_set(3)

corosync Man Page						    2004-08-31						       EVS_MCAST_GROUPS(3)