1@section File caching 2The file caching mechanism is embedded within BFD and allows 3the application to open as many BFDs as it wants without 4regard to the underlying operating system's file descriptor 5limit (often as low as 20 open files). The module in 6@code{cache.c} maintains a least recently used list of 7@code{bfd_cache_max_open} files, and exports the name 8@code{bfd_cache_lookup}, which runs around and makes sure that 9the required BFD is open. If not, then it chooses a file to 10close, closes it and opens the one wanted, returning its file 11handle. 12 13@subsection Caching functions 14 15 16@findex bfd_cache_init 17@subsubsection @code{bfd_cache_init} 18@deftypefn {Function} bool bfd_cache_init (bfd *abfd); 19Add a newly opened BFD to the cache. 20 21@end deftypefn 22@findex bfd_cache_close 23@subsubsection @code{bfd_cache_close} 24@deftypefn {Function} bool bfd_cache_close (bfd *abfd); 25Remove the BFD @var{abfd} from the cache. If the attached file is open, 26then close it too. 27 28@code{FALSE} is returned if closing the file fails, @code{TRUE} is 29returned if all is well. 30 31@end deftypefn 32@findex bfd_cache_close_all 33@subsubsection @code{bfd_cache_close_all} 34@deftypefn {Function} bool bfd_cache_close_all (void); 35Remove all BFDs from the cache. If the attached file is open, 36then close it too. Note - despite its name this function will 37close a BFD even if it is not marked as being cacheable, ie 38even if bfd_get_cacheable() returns false. 39 40@code{FALSE} is returned if closing one of the file fails, @code{TRUE} is 41returned if all is well. 42 43@end deftypefn 44@findex bfd_cache_size 45@subsubsection @code{bfd_cache_size} 46@deftypefn {Function} unsigned bfd_cache_size (void); 47Return the number of open files in the cache. 48 49@end deftypefn 50@findex bfd_open_file 51@subsubsection @code{bfd_open_file} 52@deftypefn {Function} FILE* bfd_open_file (bfd *abfd); 53Call the OS to open a file for @var{abfd}. Return the @code{FILE *} 54(possibly @code{NULL}) that results from this operation. Set up the 55BFD so that future accesses know the file is open. If the @code{FILE *} 56returned is @code{NULL}, then it won't have been put in the 57cache, so it won't have to be removed from it. 58 59@end deftypefn 60