m4_comment([$Id: txn_prepare.so,v 10.35 2004/08/13 03:39:03 bostic Exp $])

define(M4PAGELOCAL, [txn_prepare, DB_XIDDATASIZE])
include(m4/m4.seealso)

m4_pf_header(m4_ref(txn_prepare),
ifelse(M4API, C_API, [dnl
int
DB_TXN-__GT__prepare(DB_TXN *tid, u_int8_t gid__LB__DB_XIDDATASIZE__RB__);
])
ifelse(M4API, CXX_API, [dnl
int
DbTxn::prepare(u_int8_t gid__LB__DB_XIDDATASIZE__RB__);
]))

m4_idefz(DB_XIDDATASIZE)
m4_p([dnl
The m4_refT(txn_prepare) initiates the beginning of a two-phase commit.])

m4_p([dnl
In a distributed transaction environment, m4_db can be used as a local
transaction manager.  In this case, the distributed transaction manager
must send m4_italic(prepare) messages to each local manager.  The local
manager must then issue a m4_ref(txn_prepare) and await its successful
return before responding to the distributed transaction manager.  Only
after the distributed transaction manager receives successful responses
from all of its m4_italic(prepare) messages should it issue any
m4_italic(commit) messages.])

m4_p([dnl
In the case of nested transactions, preparing the parent causes all
unresolved children of the parent transaction to be committed.  Child
transactions should never be explicitly prepared.  Their fate will be
resolved along with their parent's during global recovery.])

m4_return(txn_prepare, std)

m4_parambegin
m4_param(gid, [dnl
The m4_arg(gid) parameter specifies the global transaction ID by which this
transaction will be known.  This global transaction ID will be returned
in calls to m4_ref(txn_recover), telling the application which global
transactions must be resolved.])
m4_paramend

m4_seealso(DbTxn)
m4_page_footer