CPG_INITIALIZE(3) Openais Programmer's Manual CPG_INITIALIZE(3)NAMEcpg_initialize - Create a new connection to the CPG service
SYNOPSIS
#include <openais/cpg.h>
int cpg_initialize(cpg_handle_t *handle, cpg_callbacks_t *callbacks);
DESCRIPTION
The cpg_initialize function is used to initialize a connection to the
closed process groups API.
Each application may have several connections to the CPG API. Each
application uses the handle argument to uniquely identify the connec‐
tion. The handle argument is then used in other function calls to
identify the connection to be used for communication with the CPG ser‐
vice.
Every time an CPG event occurs within the joined group, one of the
callbacks specified by the argument callbacks is called. The callback
functions are described by the following type definitions:
typedef void (*cpg_deliver_fn_t) (
cpg_handle_t handle,
struct cpg_name *group_name,
uint32_t nodeid,
uint32_t pid,
void *msg,
int msg_len);
typedef void (*cpg_confchg_fn_t) (
cpg_handle_t handle,
struct cpg_name *group_name,
struct cpg_address *member_list, int member_list_entries,
struct cpg_address *left_list, int left_list_entries,
struct cpg_address *joined_list, int joined_list_entries);
The callbacks argument is of the type:
typedef struct {
cpg_deliver_fn_t cpg_deliver_fn;
cpg_confchg_fn_t cpg_confchg_fn;
} cpg_callbacks_t;
When a configuration change occurs or a message is to be delivered one
of the callbacks is called from the cpg_dispatch() function. If a con‐
figuration change occurs, cpg_confchg_fn is called. If a delivery of a
message occurs, cpg_deliver_fn is called.
The cpg_address structure is defined
struct cpg_address {
unsigned int nodeid;
unsigned int pid;
unsigned int reason;
};
where nodeid is a 32 bit unique node identifier, pid is the process ID
of the process that has joined/left the group or sent the message, and
reason is an integer code indicating why the node join/left the group.
CPG_REASON_JOIN - the process joined a group using cpg_join().
CPG_REASON_LEAVE - the process left a group using cpg_leave()
CPG_REASON_NODEDOWN - the process left a group because the node left the cluster.
CPG_REASON_NODEUP - the process joined a group because it was already a member of a group on a node that has just joined the cluster
CPG_REASON_PROCDOWN - the process left a group without calling cpg_leave()RETURN VALUE
This call returns the CPG_OK value if successful, otherwise an error is
returned.
ERRORS
The errors are undocumented.
SEE ALSOcpg_overview(8), cpg_finalize(3), cpg_fd_get(3), cpg_dispatch(3),
cpg_join(3), cpg_leave(3), cpg_mcast_joined(3), cpg_mmembership_get(3)openais Man Page 2004-08-31 CPG_INITIALIZE(3)
