Change 26779 by [EMAIL PROTECTED] on 2006/01/11 09:52:18
Make setting 'PL_origalen = 1' before perl_parse() disable
argv[0] munging when $0 is assigned to.
Affected files ...
... //depot/perl/mg.c#400 edit
... //depot/perl/perl.c#703 edit
... //depot/perl/pod/perlembed.pod#39 edit
Differences ...
==== //depot/perl/mg.c#400 (text) ====
Index: perl/mg.c
--- perl/mg.c#399~26764~ 2006-01-10 02:51:16.000000000 -0800
+++ perl/mg.c 2006-01-11 01:52:18.000000000 -0800
@@ -2540,7 +2540,7 @@
/* The BSDs don't show the argv[] in ps(1) output, they
* show a string from the process struct and provide
* the setproctitle() routine to manipulate that. */
- {
+ if (PL_origalen != 1) {
s = SvPV_const(sv, len);
# if __FreeBSD_version > 410001
/* The leading "-" removes the "perl: " prefix,
@@ -2561,7 +2561,7 @@
}
#endif
#if defined(__hpux) && defined(PSTAT_SETCMD)
- {
+ if (PL_origalen != 1) {
union pstun un;
s = SvPV_const(sv, len);
un.pst_command = (char *)s;
==== //depot/perl/perl.c#703 (text) ====
Index: perl/perl.c
--- perl/perl.c#702~26760~ 2006-01-10 00:58:21.000000000 -0800
+++ perl/perl.c 2006-01-11 01:52:18.000000000 -0800
@@ -1439,7 +1439,10 @@
PL_origargc = argc;
PL_origargv = argv;
- {
+ if (PL_origalen != 0) {
+ PL_origalen = 1; /* don't use old PL_origalen if perl_parse() is called
again */
+ }
+ else {
/* Set PL_origalen be the sum of the contiguous argv[]
* elements plus the size of the env in case that it is
* contiguous with the argv[]. This is used in mg.c:Perl_magic_set()
==== //depot/perl/pod/perlembed.pod#39 (text) ====
Index: perl/pod/perlembed.pod
--- perl/pod/perlembed.pod#38~26762~ 2006-01-10 02:10:10.000000000 -0800
+++ perl/pod/perlembed.pod 2006-01-11 01:52:18.000000000 -0800
@@ -793,6 +793,7 @@
}
perl_construct(my_perl);
+ PL_origalen = 1; /* don't let $0 assignment update the proctitle or
embedding[0] */
exitstatus = perl_parse(my_perl, NULL, 2, embedding, NULL);
PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
if(!exitstatus) {
@@ -852,6 +853,21 @@
to get the new behaviour. This also enables the running of END blocks if
the perl_parse fails and C<perl_destruct> will return the exit value.
+=head2 $0 assignments
+
+When a perl script assigns a value to $0 then the perl runtime will
+try to make this value show up as the program name reported by "ps" by
+updating the memory pointed to by the argv passed to perl_parse() and
+also calling API functions like setproctitle() where available. This
+behaviour might not be appropriate when embedding perl and can be
+disabled by assigning the value C<1> to the variable C<PL_origalen>
+before perl_parse() is called.
+
+The F<persistent.c> example above is for instance likely to segfault
+when $0 is assigned to if the C<PL_origalen = 1;> assignment is
+removed. This because perl will try to write to the read only memory
+of the C<embedding[]> strings.
+
=head2 Maintaining multiple interpreter instances
Some rare applications will need to create more than one interpreter
End of Patch.
