This commit fixes a bug in opal progress registration that can cause
crashes when a progress function is registered while another thread is
in opal_progress(). Before this commit realloc is used to allocate
more space for progress functions but it is possible for a thread in
opal_progress() to try to read from the array that is freed by realloc
before the array is re-assigned when realloc returns. To prevent this
race use malloc + memcpy to fill the new array and atomically swap out
the old and new array pointers.
Per suggestion we now allocate a default of 8 slots for callbacks and
double the current number when we run out of space.
This commit also fixes leaking the callbacks_lp array.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
2fad3b9bc6