My program crashes normally, but doesn under Valgrind, or vice versa. Whats happening?
When a program runs under Valgrind, its environment is slightly different to when it runs natively. For example, the memory layout is different, and the way that threads are scheduled is different. Most of the time this doesn’t make any difference, but it can, particularly if your program is buggy. For example, if your program crashes because it erroneously accesses memory that is unaddressable, it’s possible that this memory will not be unaddressable when run under Valgrind. Alternatively, if your program has data races, these may not manifest under Valgrind. There isn’t anything you can do to change this, it’s just the nature of the way Valgrind works that it cannot exactly replicate a native execution environment. In the case where your program crashes due to a memory error when run natively but not when run under Valgrind, in most cases Memcheck should identify the bad memory operation.
