Re: "undefined method `synchronize' for #<Mutex:0xa0f5adc>" from embedded Ruby program

On 21/11/2012 5:38 PM, Graham Menhennitt wrote:
> The error is:
>      undefined method `synchronize' for #<Mutex:0xa0f5adc>
> If I search back over this list's archives, I can see a few other people
> with the same problem (but no solution).
>
> #include <ruby.h>
>
> int
> main(int argc, char *argv[])
> {
>      RUBY_INIT_STACK;
>      ruby_init();
>      ruby_init_loadpath();
>
>      rb_eval_string("$mutex = Mutex.new");
>      rb_eval_string("$mutex.synchronize(){}");
>
>      return 0;
> }
>
I've done a bit more investigation and found that it happens in all 1.9 
releases of Ruby, but it does NOT happen in 1.8.7.

The test program below produces:

    [:locked?, :try_lock, :lock, :unlock, :sleep, :nil?, :===, :=~, :!~,
    :eql?, :hash, :<=>, :class, :singleton_class, :clone, :dup,
    :initialize_dup, :initialize_clone, :taint, :tainted?, :untaint,
    :untrust, :untrusted?, :trust, :freeze, :frozen?, :to_s, :inspect,
    :methods, :singleton_methods, :protected_methods, :private_methods,
    :public_methods, :instance_variables, :instance_variable_get,
    :instance_variable_set, :instance_variable_defined?, :instance_of?,
    :kind_of?, :is_a?, :tap, :send, :public_send, :respond_to?,
    :respond_to_missing?, :extend, :display, :method, :public_method,
    :define_singleton_method, :object_id, :to_enum, :enum_for, :==,
    :equal?, :!, :!=, :instance_eval, :instance_exec, :__send__, :__id__]

Whereas running "ruby -e 'p Mutex.new.methods'" produces:

    [:locked?, :try_lock, :lock, :unlock, :sleep, :synchronize, :nil?,
    :===, :=~, :!~, :eql?, :hash, :<=>, :class, :singleton_class,
    :clone, :dup, :initialize_dup, :initialize_clone, :taint, :tainted?,
    :untaint, :untrust, :untrusted?, :trust, :freeze, :frozen?, :to_s,
    :inspect, :methods, :singleton_methods, :protected_methods,
    :private_methods, :public_methods, :instance_variables,
    :instance_variable_get, :instance_variable_set,
    :instance_variable_defined?, :instance_of?, :kind_of?, :is_a?, :tap,
    :send, :public_send, :respond_to?, :respond_to_missing?, :extend,
    :display, :method, :public_method, :define_singleton_method,
    :object_id, :to_enum, :enum_for, :==, :equal?, :!, :!=,
    :instance_eval, :instance_exec, :__send__, :__id__]


Note that ":synchronize" is missing from the former.

I've tried removing all gems in case one of them was doing something 
strange. I've searched the Ruby source code, but I can't see anything 
that might cause this.

Anybody got any ideas? Should I take this to ruby.core?

Thanks,
     Graham

Test program:

    #include <ruby.h>

    int
    main(int argc, char *argv[])
    {
         RUBY_INIT_STACK;
         ruby_init();
         ruby_init_loadpath();

         rb_eval_string("p Mutex.new.methods");

         return 0;
    }