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-rw-r--r--mmalloc/detach.c71
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diff --git a/mmalloc/detach.c b/mmalloc/detach.c
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+/* Finish access to a mmap'd malloc managed region.
+ Copyright 1992 Free Software Foundation, Inc.
+
+ Contributed by Fred Fish at Cygnus Support. fnf@cygnus.com
+
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA. */
+
+#include <sys/types.h>
+#include "mmprivate.h"
+
+/* Terminate access to a mmalloc managed region by unmapping all memory pages
+ associated with the region, and closing the file descriptor if it is one
+ that we opened.
+
+ Returns NULL on success.
+
+ Returns the malloc descriptor on failure, which can subsequently be used
+ for further action, such as obtaining more information about the nature of
+ the failure by examining the preserved errno value.
+
+ Note that the malloc descriptor that we are using is currently located in
+ region we are about to unmap, so we first make a local copy of it on the
+ stack and use the copy. */
+
+PTR
+mmalloc_detach (md)
+ PTR md;
+{
+ struct mdesc mtemp;
+
+ if (md != NULL)
+ {
+
+ mtemp = *(struct mdesc *) md;
+
+ /* Now unmap all the pages associated with this region by asking for a
+ negative increment equal to the current size of the region. */
+
+ if ((mtemp.morecore (&mtemp, mtemp.base - mtemp.breakval)) == NULL)
+ {
+ /* Deallocating failed. Update the original malloc descriptor
+ with any changes */
+ *(struct mdesc *) md = mtemp;
+ }
+ else
+ {
+ if (mtemp.flags & MMALLOC_DEVZERO)
+ {
+ close (mtemp.fd);
+ }
+ md = NULL;
+ }
+ }
+
+ return (md);
+}