Strange rb_gc_mark error

ruby-talk
1

Hello!

I have a pure C function, which may be called arbitrary
sequential times. If I call any rb_* function inside, including
the simple rb_warn(), I get:

BUG] rb_gc_mark(): unknown data type 0x28(0x89965b0) non object
ruby 1.8.0 (2003-08-04) [i586-linux]

The error occures after a lot of calls; it reminds me the
behaviour of a stack overflow, or something.

The C function is quite simpe:

static double foo (double *x, double *y)
{
double f = 5.000000;

rb_warn ("%f\n", f);

return f;

}

If I remove the rb_warn() call, everything works okay.

Any hints?

Regards,

···

–
University of Athens I bet the human brain
Physics Department is a kludge --Marvin Minsky

2

Hi,

···

In message “strange rb_gc_mark error” on 03/12/13, Elias Athanasopoulos elathan@phys.uoa.gr writes:

I have a pure C function, which may be called arbitrary
sequential times. If I call any rb_* function inside, including
the simple rb_warn(), I get:

BUG] rb_gc_mark(): unknown data type 0x28(0x89965b0) non object
ruby 1.8.0 (2003-08-04) [i586-linux]

The error occures after a lot of calls; it reminds me the
behaviour of a stack overflow, or something.

Show us whole program, if possible, to reproduce your error.

						matz.
3

I will try, but it is a little bit hard because the C func is called
from a C++ method deeply inside a complex inheritance tree.

Things that I can verify now are:

(a) The C func is called with no problem 8000 times.
(b) The C func is called for 3000+ and segfaults if I put a
simple rb_warn() inside. Ruby 1.8.0
(c) The C func is called for 6000+ and segfaults if I put a
simple rb_warn() inside. Ruby 1.8.1 preview 3.

Regards,

···

On Sat, Dec 13, 2003 at 10:11:12PM +0900, Yukihiro Matsumoto wrote:

Hi,

In message “strange rb_gc_mark error” > on 03/12/13, Elias Athanasopoulos elathan@phys.uoa.gr writes:

I have a pure C function, which may be called arbitrary
sequential times. If I call any rb_* function inside, including
the simple rb_warn(), I get:

BUG] rb_gc_mark(): unknown data type 0x28(0x89965b0) non object
ruby 1.8.0 (2003-08-04) [i586-linux]

The error occures after a lot of calls; it reminds me the
behaviour of a stack overflow, or something.

Show us whole program, if possible, to reproduce your error.

–
University of Athens I bet the human brain
Physics Department is a kludge --Marvin Minsky

4

Okay, it is my fault. :frowning:

While writting a C++ extension for Ruby, I do (almost everywhere):

static VALUE foo_init (…)
{
Foo *f = new Foo();
rb_iv_set (self, “ptr”, (VALUE) f);
return self;
}

static VALUE foo_bar (…)
{
Foo *f = (Foo *) rb_iv_get (self, “ptr”);
f->Bar();
return self;
}

The error ruby reports is on an address of a Foo created pointer.
If I remove the rb_iv_set() call, ruby executes correctly. But, I
have to keep the pointer somewhere in order to execute methods of
the specific class.

Any ideas?

Regards,

···

On Sun, Dec 14, 2003 at 12:02:27AM +0900, Elias Athanasopoulos wrote:

On Sat, Dec 13, 2003 at 10:11:12PM +0900, Yukihiro Matsumoto wrote:

Hi,

In message “strange rb_gc_mark error” > > on 03/12/13, Elias Athanasopoulos elathan@phys.uoa.gr writes:

I have a pure C function, which may be called arbitrary
sequential times. If I call any rb_* function inside, including
the simple rb_warn(), I get:

BUG] rb_gc_mark(): unknown data type 0x28(0x89965b0) non object
ruby 1.8.0 (2003-08-04) [i586-linux]

The error occures after a lot of calls; it reminds me the
behaviour of a stack overflow, or something.

Show us whole program, if possible, to reproduce your error.

I will try, but it is a little bit hard because the C func is called
from a C++ method deeply inside a complex inheritance tree.

Things that I can verify now are:

(a) The C func is called with no problem 8000 times.
(b) The C func is called for 3000+ and segfaults if I put a
simple rb_warn() inside. Ruby 1.8.0
(c) The C func is called for 6000+ and segfaults if I put a
simple rb_warn() inside. Ruby 1.8.1 preview 3.

–
University of Athens I bet the human brain
Physics Department is a kludge --Marvin Minsky

5

Any ideas?

Use Data_Wrap_Struct

Guy Decoux

6

I don’t know if it makes a difference, but in my libxosd-ruby code I’m
doing something similar, but it seems to work fine:

xosd *osd;
VALUE r_osd;

osd = xosd_create(lines);
r_osd = INT2FIX( (int)osd );

rb_iv_set(self, “@osd”, r_osd);

Two major differences I notice:

  1. I’m using INT2FIX instead of casting to VALUE
  2. I’m using an “@” on my variable name in rv_iv_set

Also, a quick question. Am I creating objects that won’t be GC’d by using
INT2FIX like that?

···

On Sun, 14 Dec 2003, Elias Athanasopoulos wrote:

On Sun, Dec 14, 2003 at 12:02:27AM +0900, Elias Athanasopoulos wrote:

On Sat, Dec 13, 2003 at 10:11:12PM +0900, Yukihiro Matsumoto wrote:

Hi,

In message “strange rb_gc_mark error” > > > on 03/12/13, Elias Athanasopoulos elathan@phys.uoa.gr writes:

I have a pure C function, which may be called arbitrary
sequential times. If I call any rb_* function inside, including
the simple rb_warn(), I get:

BUG] rb_gc_mark(): unknown data type 0x28(0x89965b0) non object
ruby 1.8.0 (2003-08-04) [i586-linux]

The error occures after a lot of calls; it reminds me the
behaviour of a stack overflow, or something.

Show us whole program, if possible, to reproduce your error.

I will try, but it is a little bit hard because the C func is called
from a C++ method deeply inside a complex inheritance tree.

Things that I can verify now are:

(a) The C func is called with no problem 8000 times.
(b) The C func is called for 3000+ and segfaults if I put a
simple rb_warn() inside. Ruby 1.8.0
(c) The C func is called for 6000+ and segfaults if I put a
simple rb_warn() inside. Ruby 1.8.1 preview 3.

Okay, it is my fault. :frowning:

While writting a C++ extension for Ruby, I do (almost everywhere):

static VALUE foo_init (…)
{
Foo *f = new Foo();
rb_iv_set (self, “ptr”, (VALUE) f);
return self;
}

static VALUE foo_bar (…)
{
Foo *f = (Foo *) rb_iv_get (self, “ptr”);
f->Bar();
return self;
}

The error ruby reports is on an address of a Foo created pointer.
If I remove the rb_iv_set() call, ruby executes correctly. But, I
have to keep the pointer somewhere in order to execute methods of
the specific class.

Any ideas?

Regards,

University of Athens I bet the human brain
Physics Department is a kludge --Marvin Minsky

Derek Lewis

===================================================================
Java Web-Application Developer

  Email    : email@lewisd.com
  Cellular : 604.312.2846
  Website  : http://www.lewisd.com

“If you’ve got a 5000-line JSP page that has “all in one” support
for three input forms and four follow-up screens, all controlled
by “if” statements in scriptlets, well … please don’t show it
to me :-). Its almost dinner time, and I don’t want to lose my
appetite :-).”
- Craig R. McClanahan

7

create a struct to wrap Foo objects with and let ruby handle the object:

struct FooWrap { Foo *foo; };
…
…
VALUE rb_cFooWrap;
…
…
static VALUE
FooWrap_free (FooWrap)
struct FooWrap FooWrap;
{
delete FooWrap->foo;
free(FooWrap);
}
…
…
/ defined this as the class ‘new’ method in Init */
static VALUE
rb_cFooWrap_c_new (klass)
VALUE klass;
{
struct FooWrap *FooWrap;
VALUE obj;
obj = Data_Make_Struct(klass, struct FooWrap, 0, FooWrap_free, FooWrap);
return obj;
}
…
…
static VALUE foo_init (…)
{
rb_iv_set (self, “foowrap”, rb_cFooWrap_c_new);
return self;
}

static VALUE foo_bar (…)
{
VALUE foowrap;
struct FooWrap *FooWrap;

  foowrap = rb_iv_get (self, "foowrap");
  Data_Get_Struct(foowrap, struct FooWrap, FooWrap)
  FooWrap->foo->Bar();
  return self;

}

i don’t know if you can wrap c++ class directly since Data_Make_Struct uses
ALLOC internally…

-a

···

On Sun, 14 Dec 2003, Elias Athanasopoulos wrote:

Date: Sun, 14 Dec 2003 02:33:04 +0900
From: Elias Athanasopoulos elathan@phys.uoa.gr
Newsgroups: comp.lang.ruby
Subject: Re: strange rb_gc_mark error

On Sun, Dec 14, 2003 at 12:02:27AM +0900, Elias Athanasopoulos wrote:

On Sat, Dec 13, 2003 at 10:11:12PM +0900, Yukihiro Matsumoto wrote:

Hi,

In message “strange rb_gc_mark error” > > > on 03/12/13, Elias Athanasopoulos elathan@phys.uoa.gr writes:

I have a pure C function, which may be called arbitrary
sequential times. If I call any rb_* function inside, including
the simple rb_warn(), I get:

BUG] rb_gc_mark(): unknown data type 0x28(0x89965b0) non object
ruby 1.8.0 (2003-08-04) [i586-linux]

The error occures after a lot of calls; it reminds me the
behaviour of a stack overflow, or something.

Show us whole program, if possible, to reproduce your error.

I will try, but it is a little bit hard because the C func is called
from a C++ method deeply inside a complex inheritance tree.

Things that I can verify now are:

(a) The C func is called with no problem 8000 times.
(b) The C func is called for 3000+ and segfaults if I put a
simple rb_warn() inside. Ruby 1.8.0
(c) The C func is called for 6000+ and segfaults if I put a
simple rb_warn() inside. Ruby 1.8.1 preview 3.

Okay, it is my fault. :frowning:

While writting a C++ extension for Ruby, I do (almost everywhere):

static VALUE foo_init (…)
{
Foo *f = new Foo();
rb_iv_set (self, “ptr”, (VALUE) f);
return self;
}

static VALUE foo_bar (…)
{
Foo *f = (Foo *) rb_iv_get (self, “ptr”);
f->Bar();
return self;
}

The error ruby reports is on an address of a Foo created pointer.
If I remove the rb_iv_set() call, ruby executes correctly. But, I
have to keep the pointer somewhere in order to execute methods of
the specific class.

Any ideas?

–

ATTN: please update your address books with address below!

===============================================================================

EMAIL :: Ara [dot] T [dot] Howard [at] noaa [dot] gov
PHONE :: 303.497.6469
ADDRESS :: E/GC2 325 Broadway, Boulder, CO 80305-3328
STP :: Solar-Terrestrial Physics Data | NCEI
NGDC :: http://www.ngdc.noaa.gov/
NESDIS :: http://www.nesdis.noaa.gov/
NOAA :: http://www.noaa.gov/
US DOC :: http://www.commerce.gov/

The difference between art and science is that science is what we
understand well enough to explain to a computer.
Art is everything else.
– Donald Knuth, “Discover”

/bin/sh -c ‘for l in ruby perl;do $l -e “print "\x3a\x2d\x29\x0a"”;done’
===============================================================================

8

osd = xosd_create(lines);
r_osd = INT2FIX( (int)osd );

rb_iv_set(self, "@osd", r_osd);

How do you free the object ?

Guy Decoux

9

Well, the osd object has a destroy function:

xosd_destroy(osd);

which I call from the finalizer of my ruby object.

If you mean the r_osd object, the FixNum, well, I don’t free it…
this is my first extension, and I haven’t been able to find any
documentation on writing ruby extensions outside of pickaxe.

···

On Sun, 14 Dec 2003, ts wrote:

osd = xosd_create(lines);
r_osd = INT2FIX( (int)osd );

rb_iv_set(self, “@osd”, r_osd);

How do you free the object ?

Guy Decoux

Derek Lewis

===================================================================
Java Web-Application Developer

  Email    : email@lewisd.com
  Cellular : 604.312.2846
  Website  : http://www.lewisd.com

“If you’ve got a 5000-line JSP page that has “all in one” support
for three input forms and four follow-up screens, all controlled
by “if” statements in scriptlets, well … please don’t show it
to me :-). Its almost dinner time, and I don’t want to lose my
appetite :-).”
- Craig R. McClanahan