diff options
Diffstat (limited to 'bfd/cache.c')
| -rw-r--r-- | bfd/cache.c | 372 |
1 files changed, 0 insertions, 372 deletions
diff --git a/bfd/cache.c b/bfd/cache.c deleted file mode 100644 index da16409d857..00000000000 --- a/bfd/cache.c +++ /dev/null @@ -1,372 +0,0 @@ -/* BFD library -- caching of file descriptors. - Copyright 1990, 1991, 1992, 1993, 1994, 1996, 2000, 2001 - Free Software Foundation, Inc. - Hacked by Steve Chamberlain of Cygnus Support (steve@cygnus.com). - -This file is part of BFD, the Binary File Descriptor library. - -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 of the License, 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ - -/* -SECTION - File caching - - The file caching mechanism is embedded within BFD and allows - the application to open as many BFDs as it wants without - regard to the underlying operating system's file descriptor - limit (often as low as 20 open files). The module in - <<cache.c>> maintains a least recently used list of - <<BFD_CACHE_MAX_OPEN>> files, and exports the name - <<bfd_cache_lookup>>, which runs around and makes sure that - the required BFD is open. If not, then it chooses a file to - close, closes it and opens the one wanted, returning its file - handle. - -*/ - -#include "bfd.h" -#include "sysdep.h" -#include "libbfd.h" - -static void insert PARAMS ((bfd *)); -static void snip PARAMS ((bfd *)); -static boolean close_one PARAMS ((void)); -static boolean bfd_cache_delete PARAMS ((bfd *)); - -/* -INTERNAL_FUNCTION - BFD_CACHE_MAX_OPEN macro - -DESCRIPTION - The maximum number of files which the cache will keep open at - one time. - -.#define BFD_CACHE_MAX_OPEN 10 - -*/ - -/* The number of BFD files we have open. */ - -static int open_files; - -/* -INTERNAL_FUNCTION - bfd_last_cache - -SYNOPSIS - extern bfd *bfd_last_cache; - -DESCRIPTION - Zero, or a pointer to the topmost BFD on the chain. This is - used by the <<bfd_cache_lookup>> macro in @file{libbfd.h} to - determine when it can avoid a function call. -*/ - -bfd *bfd_last_cache; - -/* - INTERNAL_FUNCTION - bfd_cache_lookup - - DESCRIPTION - Check to see if the required BFD is the same as the last one - looked up. If so, then it can use the stream in the BFD with - impunity, since it can't have changed since the last lookup; - otherwise, it has to perform the complicated lookup function. - - .#define bfd_cache_lookup(x) \ - . ((x)==bfd_last_cache? \ - . (FILE*) (bfd_last_cache->iostream): \ - . bfd_cache_lookup_worker(x)) - - */ - -/* Insert a BFD into the cache. */ - -static INLINE void -insert (abfd) - bfd *abfd; -{ - if (bfd_last_cache == NULL) - { - abfd->lru_next = abfd; - abfd->lru_prev = abfd; - } - else - { - abfd->lru_next = bfd_last_cache; - abfd->lru_prev = bfd_last_cache->lru_prev; - abfd->lru_prev->lru_next = abfd; - abfd->lru_next->lru_prev = abfd; - } - bfd_last_cache = abfd; -} - -/* Remove a BFD from the cache. */ - -static INLINE void -snip (abfd) - bfd *abfd; -{ - abfd->lru_prev->lru_next = abfd->lru_next; - abfd->lru_next->lru_prev = abfd->lru_prev; - if (abfd == bfd_last_cache) - { - bfd_last_cache = abfd->lru_next; - if (abfd == bfd_last_cache) - bfd_last_cache = NULL; - } -} - -/* We need to open a new file, and the cache is full. Find the least - recently used cacheable BFD and close it. */ - -static boolean -close_one () -{ - register bfd *kill; - - if (bfd_last_cache == NULL) - kill = NULL; - else - { - for (kill = bfd_last_cache->lru_prev; - ! kill->cacheable; - kill = kill->lru_prev) - { - if (kill == bfd_last_cache) - { - kill = NULL; - break; - } - } - } - - if (kill == NULL) - { - /* There are no open cacheable BFD's. */ - return true; - } - - kill->where = ftell ((FILE *) kill->iostream); - - return bfd_cache_delete (kill); -} - -/* Close a BFD and remove it from the cache. */ - -static boolean -bfd_cache_delete (abfd) - bfd *abfd; -{ - boolean ret; - - if (fclose ((FILE *) abfd->iostream) == 0) - ret = true; - else - { - ret = false; - bfd_set_error (bfd_error_system_call); - } - - snip (abfd); - - abfd->iostream = NULL; - --open_files; - - return ret; -} - -/* -INTERNAL_FUNCTION - bfd_cache_init - -SYNOPSIS - boolean bfd_cache_init (bfd *abfd); - -DESCRIPTION - Add a newly opened BFD to the cache. -*/ - -boolean -bfd_cache_init (abfd) - bfd *abfd; -{ - BFD_ASSERT (abfd->iostream != NULL); - if (open_files >= BFD_CACHE_MAX_OPEN) - { - if (! close_one ()) - return false; - } - insert (abfd); - ++open_files; - return true; -} - -/* -INTERNAL_FUNCTION - bfd_cache_close - -SYNOPSIS - boolean bfd_cache_close (bfd *abfd); - -DESCRIPTION - Remove the BFD @var{abfd} from the cache. If the attached file is open, - then close it too. - -RETURNS - <<false>> is returned if closing the file fails, <<true>> is - returned if all is well. -*/ - -boolean -bfd_cache_close (abfd) - bfd *abfd; -{ - if (abfd->iostream == NULL - || (abfd->flags & BFD_IN_MEMORY) != 0) - return true; - - return bfd_cache_delete (abfd); -} - -/* -INTERNAL_FUNCTION - bfd_open_file - -SYNOPSIS - FILE* bfd_open_file(bfd *abfd); - -DESCRIPTION - Call the OS to open a file for @var{abfd}. Return the <<FILE *>> - (possibly <<NULL>>) that results from this operation. Set up the - BFD so that future accesses know the file is open. If the <<FILE *>> - returned is <<NULL>>, then it won't have been put in the - cache, so it won't have to be removed from it. -*/ - -FILE * -bfd_open_file (abfd) - bfd *abfd; -{ - abfd->cacheable = true; /* Allow it to be closed later. */ - - if (open_files >= BFD_CACHE_MAX_OPEN) - { - if (! close_one ()) - return NULL; - } - - switch (abfd->direction) - { - case read_direction: - case no_direction: - abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_RB); - break; - case both_direction: - case write_direction: - if (abfd->opened_once == true) - { - abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_RUB); - if (abfd->iostream == NULL) - abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_WUB); - } - else - { - /* Create the file. - - Some operating systems won't let us overwrite a running - binary. For them, we want to unlink the file first. - - However, gcc 2.95 will create temporary files using - O_EXCL and tight permissions to prevent other users from - substituting other .o files during the compilation. gcc - will then tell the assembler to use the newly created - file as an output file. If we unlink the file here, we - open a brief window when another user could still - substitute a file. - - So we unlink the output file if and only if it has - non-zero size. */ -#ifndef __MSDOS__ - /* Don't do this for MSDOS: it doesn't care about overwriting - a running binary, but if this file is already open by - another BFD, we will be in deep trouble if we delete an - open file. In fact, objdump does just that if invoked with - the --info option. */ - struct stat s; - - if (stat (abfd->filename, &s) == 0 && s.st_size != 0) - unlink (abfd->filename); -#endif - abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_WUB); - abfd->opened_once = true; - } - break; - } - - if (abfd->iostream != NULL) - { - if (! bfd_cache_init (abfd)) - return NULL; - } - - return (FILE *) abfd->iostream; -} - -/* -INTERNAL_FUNCTION - bfd_cache_lookup_worker - -SYNOPSIS - FILE *bfd_cache_lookup_worker(bfd *abfd); - -DESCRIPTION - Called when the macro <<bfd_cache_lookup>> fails to find a - quick answer. Find a file descriptor for @var{abfd}. If - necessary, it open it. If there are already more than - <<BFD_CACHE_MAX_OPEN>> files open, it tries to close one first, to - avoid running out of file descriptors. -*/ - -FILE * -bfd_cache_lookup_worker (abfd) - bfd *abfd; -{ - if ((abfd->flags & BFD_IN_MEMORY) != 0) - abort (); - - if (abfd->my_archive) - abfd = abfd->my_archive; - - if (abfd->iostream != NULL) - { - /* Move the file to the start of the cache. */ - if (abfd != bfd_last_cache) - { - snip (abfd); - insert (abfd); - } - } - else - { - if (bfd_open_file (abfd) == NULL) - return NULL; - if (fseek ((FILE *) abfd->iostream, abfd->where, SEEK_SET) != 0) - return NULL; - } - - return (FILE *) abfd->iostream; -} |