qhashtbl(0, QHASHTBL_THREADSAFE): double free or corruption (top): 0x0000000001d100b0 ***

[allanwind]

I modified examples/hashtbl.c as follows:

• qhashtbl_t *tbl = qhashtbl(0, 0);
  

• qhashtbl_t *tbl = qhashtbl(0, QHASHTBL_THREADSAFE);

which then crashes with:

allan@vent:~/src/qlibc/examples$ ./hashtbl
*** Error in `./hashtbl': double free or corruption (top): 0x00000000015010b0 ***
Aborted

What am I missing?

[refi64]

For some reason, this is returning true. Likely an issue with the mutex allocation code, because I can reproduce this, and I have plenty of memory left.

Now, when it jumps to malloc_failure, it calls qhashtbl_free. According to GDB, this is where the corruption occurs.

[refi64]

Found it!

This line frees tbl->slots, BUT it doesn't set it to NULL. Two lines later, qhashtbl_free is called, which frees it again.

This still doesn't explain why the malloc failure is even occurring, though...