1CPG_INITIALIZE(3) Corosync Cluster Engine Programmer's ManualCPG_INITIALIZE(3)
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6 cpg_initialize - Create a new connection to the CPG service
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9 #include <corosync/cpg.h>
10 int cpg_initialize(cpg_handle_t *handle, cpg_callbacks_t *callbacks);
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14 The cpg_initialize function is used to initialize a connection to the
15 closed process groups API. This function is deprecated and
16 cpg_model_initialize should be used in newly written code.
17 Each application may have several connections to the CPG API. Each
19 application uses the handle argument to uniquely identify the connec‐
20 tion. The handle argument is then used in other function calls to
21 identify the connection to be used for communication with the CPG ser‐
22 vice.
23 Every time an CPG event occurs within the joined group, one of the
25 callbacks specified by the argument callbacks is called. The callback
26 functions are described by the following type definitions:
27 typedef void (*cpg_deliver_fn_t) (
29 cpg_handle_t handle,
30 const struct cpg_name *group_name,
31 uint32_t nodeid,
32 uint32_t pid,
33 const void *msg,
34 size_t msg_len);
35 typedef void (*cpg_confchg_fn_t) (
38 cpg_handle_t handle,
39 const struct cpg_name *group_name,
40 const struct cpg_address *member_list, size_t member_list_entries,
41 const struct cpg_address *left_list, size_t left_list_entries,
42 const struct cpg_address *joined_list, size_t joined_list_entries);
43 The callbacks argument is of the type:
46 typedef struct {
48 cpg_deliver_fn_t cpg_deliver_fn;
49 cpg_confchg_fn_t cpg_confchg_fn;
50 } cpg_callbacks_t;
51 When a configuration change occurs or a message is to be delivered one
53 of the callbacks is called from the cpg_dispatch() function. If a con‐
54 figuration change occurs, cpg_confchg_fn is called. If a delivery of a
55 message occurs, cpg_deliver_fn is called.
56 The cpg_address structure is defined
58 struct cpg_address {
60 unsigned int nodeid;
61 unsigned int pid;
62 unsigned int reason;
63 };
64 where nodeid is a 32 bit unique node identifier, pid is the process ID
66 of the process that has joined/left the group or sent the message, and
67 reason is an integer code indicating why the node joined/left the group
68 (this value is not set for the member_list items).
69 CPG_REASON_JOIN - the process joined a group using cpg_join().
71 CPG_REASON_LEAVE - the process left a group using cpg_leave()
72 CPG_REASON_NODEDOWN - the process left a group because the node left the cluster.
73 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
74 CPG_REASON_PROCDOWN - the process left a group without calling cpg_leave()
75 CPG_REASON_UNDEFINED - a special value used for the member_list items
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78 This call returns the CS_OK value if successful, otherwise an error is
79 returned.
80
82 The errors are undocumented.
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85 cpg_overview(3), cpg_initialize(3), cpg_finalize(3), cpg_fd_get(3),
86 cpg_dispatch(3), cpg_join(3), cpg_leave(3), cpg_mcast_joined(3),
87 cpg_membership_get(3) cpg_zcb_alloc(3) cpg_zcb_free(3)
88 cpg_zcb_mcast_joined(3) cpg_context_get(3) cpg_context_set(3)
89 cpg_local_get(3) cpg_model_initialize(3)
90 CS_ERR_TRY_AGAIN Resource temporarily unavailable
93 CS_ERR_INVALID_PARAM Invalid argument
95 CS_ERR_ACCESS Permission denied
97 CS_ERR_LIBRARY The connection failed
99 CS_ERR_INTERRUPT System call interrupted by a signal
101 CS_ERR_NOT_SUPPORTED The requested protocol/functionality not supported
103 CS_ERR_MESSAGE_ERROR Incorrect auth message received
105 CS_ERR_NO_MEMORY Not enough memory to complete the requested task
107corosync Man Page 2019-04-16 CPG_INITIALIZE(3)