I changed it to
#include <pthread.h>

void *thread(void *arg) {
    char *msg = (char*)arg;
    printf("thread: %s\n", msg);
    free(msg);
    return NULL;
}

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "ppport.h"

MODULE = My    PACKAGE = My

void
test_thread(char *msg)
    PPCODE:
        char *thread_arg = malloc((strlen(msg)+1)*sizeof(char));
        strcpy(thread_arg, msg);
        pthread_t tid;
        pthread_create(&tid, NULL, thread, (void*)thread_arg);
        
        void *rv;
        pthread_join(tid, &rv);

[download]

And the problem still here: crash on each run

In reply to Re^6: XS: free() outside of the main thread causes crash on Windows by OlegG
in thread XS: free() outside of the main thread causes crash on Windows by OlegG

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.