ObjectSpace.trace_object_allocations_start

static VALUE
trace_object_allocations_start(VALUE self)
{
    struct traceobj_arg *arg = get_traceobj_arg();

    if (arg->running++ > 0) {
        /* do nothing */
    }
    else {
        if (arg->newobj_trace == 0) {
            arg->newobj_trace = rb_tracepoint_new(0, RUBY_INTERNAL_EVENT_NEWOBJ, newobj_i, arg);
            arg->freeobj_trace = rb_tracepoint_new(0, RUBY_INTERNAL_EVENT_FREEOBJ, freeobj_i, arg);
        }
        rb_tracepoint_enable(arg->newobj_trace);
        rb_tracepoint_enable(arg->freeobj_trace);
    }

    return Qnil;
}