| /* 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); |
| } |