# enable debug/trace messages from DynaLoader perl code
$dl_debug = $ENV{PERL_DL_DEBUG} || 0 unless defined $dl_debug;
+#
+# Flags to alter dl_load_file behaviour. Assigned bits:
+# 0x01 make symbols available for linking later dl_load_file's.
+# (only known to work on Solaris 2 using dlopen(RTLD_GLOBAL))
+#
+# This is called as a class method $module->dl_load_flags. The
+# definition here will be inherited and result on "default" loading
+# behaviour unless a sub-class of DynaLoader defines its own version.
+#
+
+sub dl_load_flags { 0x00 }
+
+#
+
($dl_dlext, $dlsrc)
= @Config::Config{'dlext', 'dlsrc'};
@dl_require_symbols = (); # names of symbols we need
@dl_resolve_using = (); # names of files to link with
@dl_library_path = (); # path to look for files
+@dl_librefs = (); # things we have loaded
+@dl_modules = (); # Modules we have loaded
# This is a fix to support DLD's unfortunate desire to relink -lc
@dl_resolve_using = dl_findfile('-lc') if $dlsrc eq "dl_dld.xs";
# in this perl code simply because this was the last perl code
# it executed.
- my $libref = dl_load_file($file) or
+ my $libref = dl_load_file($file, $module->dl_load_flags) or
Carp::croak("Can't load '$file' for module $module: ".dl_error()."\n");
+ push(@dl_librefs,$libref); # record loaded object
+
my @unresolved = dl_undef_symbols();
Carp::carp("Undefined symbols present after loading $file: @unresolved\n")
if @unresolved;
my $xs = dl_install_xsub("${module}::bootstrap", $boot_symbol_ref, $file);
+ push(@dl_modules, $module); # record loaded module
+
# See comment block above
&$xs(@args);
}
$file;
}
+sub dl_find_symbol_anywhere
+{
+ my $sym = shift;
+ my $libref;
+ foreach $libref (@dl_librefs) {
+ my $symref = dl_find_symbol($libref,$sym);
+ return $symref if $symref;
+ }
+ return undef;
+}
=head1 NAME
DynaLoader - Dynamically load C libraries into Perl code
-dl_error(), dl_findfile(), dl_expandspec(), dl_load_file(), dl_find_symbol(), dl_undef_symbols(), dl_install_xsub(), bootstrap() - routines used by DynaLoader modules
+dl_error(), dl_findfile(), dl_expandspec(), dl_load_file(), dl_find_symbol(), dl_find_symbol_anywhere(), dl_undef_symbols(), dl_install_xsub(), dl_load_flags(), bootstrap() - routines used by DynaLoader modules
=head1 SYNOPSIS
@ISA = qw(... DynaLoader ...);
bootstrap YourPackage;
+ # optional method for 'global' loading
+ sub dl_load_flags { 0x01 }
+
=head1 DESCRIPTION
@dl_resolve_using
@dl_require_symbols
$dl_debug
+ @dl_librefs
+ @dl_modules
Implemented in:
bootstrap($modulename) Perl
@filepaths = dl_findfile(@names) Perl
+ $flags = $modulename->dl_load_flags Perl
+ $symref = dl_find_symbol_anywhere($symbol) Perl
- $libref = dl_load_file($filename) C
+ $libref = dl_load_file($filename, $flags) C
$symref = dl_find_symbol($libref, $symbol) C
@symbols = dl_undef_symbols() C
dl_install_xsub($name, $symref [, $filename]) C
A list of one or more symbol names that are in the library/object file
to be dynamically loaded. This is only required on some platforms.
+=item @dl_librefs
+
+An array of the handles returned by successful calls to dl_load_file(),
+made by bootstrap, in the order in which they were loaded.
+Can be used with dl_find_symbol() to look for a symbol in any of
+the loaded files.
+
+=item @dl_modules
+
+An array of module (package) names that have been bootstrap'ed.
+
=item dl_error()
Syntax:
Syntax:
- $libref = dl_load_file($filename)
+ $libref = dl_load_file($filename, $flags)
Dynamically load $filename, which must be the path to a shared object
or library. An opaque 'library reference' is returned as a handle for
the loaded object. Returns undef on error.
+The $flags argument to alters dl_load_file behaviour.
+Assigned bits:
+
+ 0x01 make symbols available for linking later dl_load_file's.
+ (only known to work on Solaris 2 using dlopen(RTLD_GLOBAL))
+
(On systems that provide a handle for the loaded object such as SunOS
and HPUX, $libref will be that handle. On other systems $libref will
typically be $filename or a pointer to a buffer containing $filename.
The application should not examine or alter $libref in any way.)
-This is function that does the real work. It should use the current
-values of @dl_require_symbols and @dl_resolve_using if required.
+This is the function that does the real work. It should use the
+current values of @dl_require_symbols and @dl_resolve_using if required.
SunOS: dlopen($filename)
HP-UX: shl_load($filename)
NeXT: rld_load($filename, @dl_resolve_using)
VMS: lib$find_image_symbol($filename,$dl_require_symbols[0])
+(The dlopen() function is also used by Solaris and some versions of
+Linux, and is a common choice when providing a "wrapper" on other
+mechanisms as is done in the OS/2 port.)
+
+=item dl_loadflags()
+
+Syntax:
+
+ $flags = dl_loadflags $modulename;
+
+Designed to be a method call, and to be overridden by a derived class
+(i.e. a class which has DynaLoader in its @ISA). The definition in
+DynaLoader itself returns 0, which produces standard behavior from
+dl_load_file().
=item dl_find_symbol()
VMS: lib$find_image_symbol($libref,$symbol)
+=item dl_find_symbol_anywhere()
+
+Syntax:
+
+ $symref = dl_find_symbol_anywhere($symbol)
+
+Applies dl_find_symbol() to the members of @dl_librefs and returns
+the first match found.
+
=item dl_undef_symbols()
Example
=item *
+calls dl_load_flags() to determine how to load the file.
+
+=item *
+
calls dl_load_file() to load the file
=item *
Larry Wall designed the elegant inherited bootstrap mechanism and
implemented the first Perl 5 dynamic loader using it.
+Solaris global loading added by Nick Ing-Simmons with design/coding
+assistance from Tim Bunce, January 1996.
+
=cut
projects / p5sagit/p5-mst-13.2.git / commitdiff