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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997
* Sleepycat Software. All rights reserved.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)db_thread.c 8.11 (Sleepycat) 8/18/97";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#endif
#include "db_int.h"
#include "db_page.h"
#include "shqueue.h"
#include "db_am.h"
static int __db_getlockid __P((DB *, DB *));
/*
* __db_gethandle --
* Called by db access method routines when the DB_THREAD flag is set.
* This routine returns a handle, either an existing handle from the
* chain of handles, or creating one if necessary.
*
* PUBLIC: int __db_gethandle __P((DB *, int (*)(DB *, DB *), DB **));
*/
int
__db_gethandle(dbp, am_func, dbpp)
DB *dbp, **dbpp;
int (*am_func) __P((DB *, DB *));
{
DB *ret_dbp;
int ret, t_ret;
if ((ret = __db_mutex_lock((db_mutex_t *)dbp->mutex, -1,
dbp->dbenv == NULL ? NULL : dbp->dbenv->db_yield)) != 0)
return (ret);
if ((ret_dbp = LIST_FIRST(&dbp->handleq)) != NULL)
/* Simply take one off the list. */
LIST_REMOVE(ret_dbp, links);
else {
/* Allocate a new handle. */
if ((ret_dbp = (DB *)malloc(sizeof(*dbp))) == NULL) {
ret = ENOMEM;
goto err;
}
memcpy(ret_dbp, dbp, sizeof(*dbp));
ret_dbp->internal = NULL;
TAILQ_INIT(&ret_dbp->curs_queue);
/* Set the locker, the lock structure and the lock DBT. */
if ((ret = __db_getlockid(dbp, ret_dbp)) != 0)
goto err;
/* Finally, call the access method specific dup function. */
if ((ret = am_func(dbp, ret_dbp)) != 0)
goto err;
}
*dbpp = ret_dbp;
if (0) {
err: if (ret_dbp != NULL)
FREE(ret_dbp, sizeof(*ret_dbp));
}
if ((t_ret =
__db_mutex_unlock((db_mutex_t *)dbp->mutex, -1)) != 0 && ret == 0)
ret = t_ret;
return (ret);
}
/*
* __db_puthandle --
* Return a DB handle to the pool for later use.
*
* PUBLIC: int __db_puthandle __P((DB *));
*/
int
__db_puthandle(dbp)
DB *dbp;
{
DB *master;
int ret;
master = dbp->master;
if ((ret = __db_mutex_lock((db_mutex_t *)master->mutex, -1,
dbp->dbenv == NULL ? NULL : dbp->dbenv->db_yield)) != 0)
return (ret);
LIST_INSERT_HEAD(&master->handleq, dbp, links);
return (__db_mutex_unlock((db_mutex_t *)master->mutex, -1));
}
/*
* __db_getlockid --
* Create a new locker ID and copy the file lock information from
* the old DB into the new one.
*/
static int
__db_getlockid(dbp, new_dbp)
DB *dbp, *new_dbp;
{
int ret;
if (F_ISSET(dbp, DB_AM_LOCKING)) {
if ((ret = lock_id(dbp->dbenv->lk_info, &new_dbp->locker)) != 0)
return (ret);
memcpy(new_dbp->lock.fileid, dbp->lock.fileid, DB_FILE_ID_LEN);
new_dbp->lock_dbt.size = sizeof(new_dbp->lock);
new_dbp->lock_dbt.data = &new_dbp->lock;
}
return (0);
}
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