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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997, 1998, 1999, 2000
* Sleepycat Software. All rights reserved.
*/
#include "db_config.h"
#ifndef lint
static const char revid[] = "$Id: os_region.c,v 11.9 2000/11/30 00:58:42 ubell Exp $";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#endif
#include "db_int.h"
#include "os_jump.h"
/*
* __os_r_attach --
* Attach to a shared memory region.
*
* PUBLIC: int __os_r_attach __P((DB_ENV *, REGINFO *, REGION *));
*/
int
__os_r_attach(dbenv, infop, rp)
DB_ENV *dbenv;
REGINFO *infop;
REGION *rp;
{
int ret;
/* Round off the requested size for the underlying VM. */
OS_VMROUNDOFF(rp->size);
#ifdef DB_REGIONSIZE_MAX
/* Some architectures have hard limits on the maximum region size. */
if (rp->size > DB_REGIONSIZE_MAX) {
__db_err(dbenv, "region size %lu is too large; maximum is %lu",
(u_long)rp->size, (u_long)DB_REGIONSIZE_MAX);
return (EINVAL);
}
#endif
/*
* If a region is private, malloc the memory.
*
* !!!
* If this fails because the region is too large to malloc, mmap(2)
* using the MAP_ANON or MAP_ANONYMOUS flags would be an alternative.
* I don't know of any architectures (yet!) where malloc is a problem.
*/
if (F_ISSET(dbenv, DB_ENV_PRIVATE)) {
#if defined(MUTEX_NO_MALLOC_LOCKS)
/*
* !!!
* There exist spinlocks that don't work in malloc memory, e.g.,
* the HP/UX msemaphore interface. If we don't have locks that
* will work in malloc memory, we better not be private or not
* be threaded.
*/
if (F_ISSET(dbenv, DB_ENV_THREAD)) {
__db_err(dbenv, "%s",
"architecture does not support locks inside process-local (malloc) memory");
__db_err(dbenv, "%s",
"application may not specify both DB_PRIVATE and DB_THREAD");
return (EINVAL);
}
#endif
if ((ret =
__os_malloc(dbenv, rp->size, NULL, &infop->addr)) != 0)
return (ret);
#if defined(UMRW) && !defined(DIAGNOSTIC)
memset(infop->addr, CLEAR_BYTE, rp->size);
#endif
return (0);
}
/* If the user replaced the map call, call through their interface. */
if (__db_jump.j_map != NULL)
return (__db_jump.j_map(infop->name,
rp->size, 1, 0, &infop->addr));
return (__os_r_sysattach(dbenv, infop, rp));
}
/*
* __os_r_detach --
* Detach from a shared memory region.
*
* PUBLIC: int __os_r_detach __P((DB_ENV *, REGINFO *, int));
*/
int
__os_r_detach(dbenv, infop, destroy)
DB_ENV *dbenv;
REGINFO *infop;
int destroy;
{
REGION *rp;
rp = infop->rp;
/* If a region is private, free the memory. */
if (F_ISSET(dbenv, DB_ENV_PRIVATE)) {
__os_free(infop->addr, rp->size);
return (0);
}
/* If the user replaced the map call, call through their interface. */
if (__db_jump.j_unmap != NULL)
return (__db_jump.j_unmap(infop->addr, rp->size));
return (__os_r_sysdetach(dbenv, infop, destroy));
}
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