cpg_zcb_mcast_joined (3) - Linux Manuals

cpg_zcb_mcast_joined: Multicasts a zero copy buffer to all groups joined to a handle

NAME

cpg_mcast_joined - Multicasts a zero copy buffer to all groups joined to a handle

SYNOPSIS

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

int cpg_zcb_mcast_joined(cpg_handle_t handle, cpg_guarantee_t guarantee, const void *buffer,int msg_len );

DESCRIPTION

The cpg_zcb_mcast_joined function will multicast a zero copy buffer message to all the processes that have been joined with the cpg_join(3) function for the same group name. Messages that are sent to any of the groups joined to the parameter handle will be delivered to all subscribed processes in the system.

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

typedef enum {
        CPG_TYPE_UNORDERED,     /* not implemented */
        CPG_TYPE_FIFO,          /* same as agreed */
        CPG_TYPE_AGREED,        /* implemented */
        CPG_TYPE_SAFE           /* not implemented */
} cpg_guarantee_t;

The meanings of the cpg_guarantee_t typedef are:

CPG_TYPE_UNORDERED

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

CPG_TYPE_FIFO

Messages are guaranteed to be delivered in first sent first delivery order. In fact, this guarantee is equivalent to the CPG_TYPE_AGREED guarantee.

CPG_TYPE_AGREED

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

CPG_TYPE_SAFE

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

The msg argument describes the zero copy buffer which is used to transmit a message. this buffer must be allocated by cpg_zcb_alloc(3).

The msg_len argument describes the number of bytes to be transmitted in the zero copy buffer.

RETURN VALUE

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

ERRORS

The errors are undocumented.