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evs_initialize

NAME

evs_initialize - Create a new connection to the EVS service

SYNOPSIS

#include <corosync/evs.h>

int evs_initialize(evs_handle_t *handle, evs_callbacks_t *callbacks);

DESCRIPTION

The evs_initialize function is used to initialize a connection to the extended virtual synchrony API.

Each application may have several connections to the EVS API. Each application uses the handle argument to uniquely identify the connection. The handle argument is then used in other function calls to identify the connection to be used for communication with the EVS service.

Every time an EVS event occurs, one of the callbacks specified by the argument callbacks is called. The callback functions are described by the following type definitions:

 
 typedef void (*evs_deliver_fn_t) (
         struct evs_address source_addr,
         void *msg,
         int msg_len);
 
 typedef void (*evs_confchg_fn_t) (
         struct evs_address *member_list, int member_list_entries,
         struct evs_address *left_list, int left_list_entries,
         struct evs_address *joined_list, int joined_list_entries);
 
 

The callbacks argument is of the type:

 
 typedef struct {
         evs_deliver_fn_t evs_deliver_fn;
         evs_confchg_fn_t evs_confchg_fn;
 } evs_callbacks_t;
 
 

When a configuration change occurs or a message is to be delivered one of the callbacks is called from the evs_dispatch() function. If a configuration change occurs, evs_confchg_fn is called. If a delivery of a message occurs, evs_deliver_fn is called.

The evs_address structure is defined

 
 struct evs_address {
         unsigned int nodeid;
         unsigned short family;
         unsigned char addr[TOTEMIP_ADDRLEN];
 };
 
 

where nodeid is a 32 bit unique node identifier, family is of the value AF_INET for an IPV4 network, or AF_INET6 for an IPV6 network, and addr is a 32 bit address for an IPV4 network, or 128 bit address for an IPV6 network.

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_finalize(3), evs_fd_get(3), evs_dispatch(3), evs_join(3), evs_leave(3), evs_mcast_joined(3), evs_mcast_groups(3), evs_mmembership_get(3)