evs_join − Multicast a message to selected groups
#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);
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 */ | ||
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EVS_TYPE_FIFO, /* same as agreed */ |
|||
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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
{
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void *iov_base; /* Pointer to data. */ |
||
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unsigned int iov_len; /* Length of data. */ |
};
The iovlen argument describes the number of entires in the iovec argument.
This call returns the EVS_OK value if successful, otherwise an error is returned.
The errors are undocumented.
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_membership_get(3) evs_context_get(3) evs_context_set(3)