event.so

berkeley db 4.6.21的源码。berkeley db是一个简单的数据库管理系统

m4_comment([$Id: event.so,v 1.2 2007/05/14 16:03:56 bostic Exp $])

m4_ref_title(Upgrading m4_db Applications,
    Release 4.6: replication events,,
    upgrade.4.6/memp_fset, upgrade.4.6/full_election)

m4_p([dnl
It is now guaranteed the m4_ref(DB_EVENT_REP_STARTUPDONE) event will be
presented to the application after the corresponding
m4_ref(DB_EVENT_REP_NEWMASTER) event, even in the face of extreme
thread-scheduling anomalies.  (In previous releases, if the thread
processing the NEWMASTER message was starved, and STARTUPDONE occurred
soon after, the order might have been reversed.)])

m4_p([dnl
In addition, the m4_ref(DB_EVENT_REP_NEWMASTER) event is now presented
to all types of replication applications: users of either the
Replication Framework or the Base Replication API.  In both cases, the
m4_ref(DB_EVENT_REP_NEWMASTER) event always means that a site other than
the local environment has become master.])

m4_p([dnl
The m4_arg(envid) parameter to m4_ref(rep_message) has been changed to
be of type "int" rather than "int *", and the environment ID of a new
master is presented to the application along with the
m4_ref(DB_EVENT_REP_NEWMASTER) event.  Replication applications should
be modified to use the m4_ref(DB_EVENT_REP_NEWMASTER) event to determine
the ID of the new master.])

m4_p([dnl
The m4_arg(envid) parameter has been removed from the m4_ref(rep_elect)
method and a new event type has been added.  The
m4_ref(DB_EVENT_REP_ELECTED) event is presented to the application at
the site which wins an election.  In the m4_db 4.6 release, the normal
result of a successful election is either the
m4_ref(DB_EVENT_REP_NEWMASTER) event (with the winner's environment ID),
or the m4_ref(DB_EVENT_REP_ELECTED) event.  Only one of the two events
will ever be delivered.])

m4_p([dnl
The DB_REP_NEWMASTER return code has been removed from the
m4_refT(rep_message).  Replication applications should be modified to
use the m4_ref(DB_EVENT_REP_NEWMASTER) and m4_ref(DB_EVENT_REP_ELECTED)
events to determine the existence of a new master.])

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