Function ExpandEventArray

source/keyboard_mouse.cpp:2688–2716

ResultType ExpandEventArray()
// Returns OK or FAIL.
{
	if (sAbortArraySend) // A prior call failed (might be impossible).  Avoid malloc() in this case.
		return FAIL;
	#define EVENT_EXPANSION_MULTIPLIER 2  // Should be very rare for array to need to expand more than a few times.
	size_t event_size = (sSendMode == SM_INPUT) ? sizeof(INPUT) : sizeof(PlaybackEvent);
	void *new_mem;
	// SendInput() appears to be limited to 5000 chars (10000 events in array), at least on XP.  This is
	// either an undocumented SendInput limit or perhaps it's due to the system setting that determines
	// how many messages can get backlogged in each thread's msg queue before some start to get dropped.
	// Note that SendInput()'s return value always seems to indicate that all the characters were sent
	// even when the ones beyond the limit were clearly never received by the target window.
	// In any case, it seems best not to restrict to 5000 here in case the limit can vary for any reason.
	// The 5000 limit is documented in the help file.
	if (   !(new_mem = malloc(EVENT_EXPANSION_MULTIPLIER * sMaxEvents * event_size))   )
	{
		sAbortArraySend = true; // Usually better to send nothing rather than partial.
		// Leave sEventSI and sMaxEvents in their current valid state, to be freed by CleanupEventArray().
		return FAIL;
	}
	else // Copy old array into new memory area (note that sEventSI and sEventPB are different views of the same variable).
		memcpy(new_mem, sEventSI, sEventCount * event_size);
	if (sMaxEvents > (sSendMode == SM_INPUT ? MAX_INITIAL_EVENTS_SI : MAX_INITIAL_EVENTS_PB))
		free(sEventSI); // Previous block was malloc'd vs. _alloc'd, so free it.
	sEventSI = (LPINPUT)new_mem; // Note that sEventSI and sEventPB are different views of the same variable.
	sMaxEvents *= EVENT_EXPANSION_MULTIPLIER;
	return OK;
}