Function internal_compatible

src/jrd/lck.cpp:1223–1263

static bool internal_compatible(Lock* match, const Lock* lock, USHORT level)
{
/**************************************
 *
 *	i n t e r n a l _ c o m p a t i b l e
 *
 **************************************
 *
 * Functional description
 *	See if there are any incompatible locks
 *	in the list of locks held by this process.
 *	If there are none, return true to indicate
 *	that the lock is compatible.
 *
 **************************************/
	fb_assert(LCK_CHECK_LOCK(match));
	fb_assert(LCK_CHECK_LOCK(lock));

	// first check if there are any locks which are incompatible which do not have blocking asts;
	// if so, there is no chance of getting a compatible lock

	for (const Lock* next = match; next; next = next->lck_identical)
	{
		if (!next->lck_ast && !compatible(next, lock, level))
			return false;
	}

	// now deliver the blocking asts, attempting to gain
	// compatibility by getting everybody to downgrade
	internal_ast(match);

	// make one more pass to see if all locks were downgraded

	for (const Lock* next = match; next; next = next->lck_identical)
	{
		if (!compatible(next, match, level))
			return false;
	}

	return true;
}


static void internal_dequeue(thread_db* tdbb, Lock* lock)