Do strings from rb_str_new and friends need to be free'd?

Ruby
1

Hi,

I have some C native code that calls a logging class written in Ruby. To
pass the message string to the Ruby class, I am creating a string with
rb_str_new2 and then passing its VALUE to rb_funcall. I am wondering if
I
need to do any clean-up for the string, or will Ruby handle this for me?

Also, if anyone can suggest an awesome doc on writing Ruby native
extensions, that would be appreciated. At the moment, I am mostly using
the
Pickaxe online book.

Here is the code in question:

void log_warning(const char *fmt, ...)
{
    char message[BUFFER_LEN]; // Temporary buffer to hold the

generated
message

    // Evaluate the format string and store it in the temporary

buffer
va_list ap;
va_start(ap, fmt);
vsnprintf(message, BUFFER_LEN, fmt, ap);
va_end(ap);

    // Find the ID's to call tho Log.warning Ruby class method
    rb_require("log");
    ID log_class = rb_path2class("Log");
    ID log_warning_method = rb_intern("warning");

    // Create a Ruby string containing a copy of the formatted

message
VALUE message_value = rb_str_new2(message);

    // Call Log.warning, with the formatted message as an argument
    rb_funcall(log_class, log_warning_method, 1, message_value);

    // Do I need to do anything here to tell Ruby to clean up the

string?
}

Thanks!

-Steven

2

Ah, cool. Thanks, Matz!

-Steven

On Sat, May 10, 2008 at 1:36 PM, Yukihiro M. [email protected]

3

Hi,

In message “Re: Do strings from rb_str_new and friends need to be
free’d?”
on Sat, 10 May 2008 12:21:57 +0900, “Steven Kah Hien Wong”
[email protected] writes:

|I have some C native code that calls a logging class written in Ruby. To
|pass the message string to the Ruby class, I am creating a string with
|rb_str_new2 and then passing its VALUE to rb_funcall. I am wondering if I
|need to do any clean-up for the string, or will Ruby handle this for me?

The latter. You don’t have to (and you shouldn’t) free string
objects.

          matz.