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


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


#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 );


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:

Messages are guaranteed to be delivered, but with no particular order. This mode is unimplemented in the CPG library.
Messages are guaranteed to be delivered in first sent first delivery order. In fact, this guarantee is equivalent to the CPG_TYPE_AGREED guarantee.
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.
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.


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


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_local_get(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

2004-08-31 corosync Man Page