SYNOPSIS

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

int evs_mcast_joined(evs_handle_t handle, evs_guraantee_t guarantee, struct iovec *iovec, int iov_len);

DESCRIPTION

The evs_mcast_joined function is multicast a message to all the groups that have been joined with the evs_join(3) function for the argument handle. Messages that are sent to any of the groups joined to the parameter handle will be delivered to all processors in the system.

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 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.

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