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/* Changing pager attributes synchronously
Copyright (C) 1994 Free Software Foundation
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "priv.h"
#include <assert.h>
/* Change the attributes of the memory object underlying pager P.
Args MAY_CACHE and COPY_STRATEGY are as for
memory_object_change_atributes. Wait for the kernel to report completion
off WAIT is set.*/
void
pager_change_attributes (struct pager *p,
boolean_t may_cache,
memory_object_copy_strategy_t copy_strategy,
int wait)
{
struct attribute_request *ar = 0;
mutex_lock (&p->interlock);
p->may_cache = may_cache;
p->copy_strategy = copy_strategy;
if (p->pager_state == NOTINIT)
{
mutex_unlock (&p->interlock);
return;
}
if (wait)
{
for (ar = p->attribute_requests; ar; ar = ar->next)
if (ar->may_cache == may_cache
&& ar->copy_strategy == copy_strategy)
{
ar->attrs_pending++;
ar->threads_waiting++;
break;
}
if (!ar)
{
ar = malloc (sizeof (struct attribute_request));
ar->may_cache = may_cache;
ar->copy_strategy = copy_strategy;
ar->attrs_pending = 1;
ar->threads_waiting = 1;
ar->next = p->attribute_requests;
if (ar->next)
ar->next->prevp = &ar->next;
ar->prevp = &p->attribute_requests;
p->attribute_requests = ar;
}
}
memory_object_change_attributes (p->memobjcntl, may_cache, copy_strategy,
wait ? p->port.port_right : MACH_PORT_NULL);
if (wait)
{
while (ar->attrs_pending)
condition_wait (&p->wakeup, &p->interlock);
if (!--ar->threads_waiting)
{
*ar->prevp = ar->next;
free (ar);
}
}
mutex_unlock (&p->interlock);
}
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