Description:
------------
when exec "opcache_reset()" by cacheTool, We offen get Fatal error：[25-Nov-2016 14:07:07 Asia/Shanghai] PHP Fatal error:  Unknown: Failed opening required '/home/xxxx/index.php' (include_path='.:/home/php7/lib/php') in Unknown on line 0(just on error log,not warning), then I check ZendAccelerator.c, find this code:
 static zend_string *accel_find_interned_string(zend_string *str)
{
/* for now interned strings are supported only for non-ZTS build */
	zend_ulong h;
	uint nIndex;
	uint idx;
	Bucket *arData, *p;

	if (IS_ACCEL_INTERNED(str)) {
		/* this is already an interned string */
		return str;
	}
	if (!ZCG(counted)) {
		if (accel_activate_add() == FAILURE) {
			return str;
		}
		ZCG(counted) = 1;
	}

	h = zend_string_hash_val(str);
	nIndex = h | ZCSG(interned_strings).nTableMask;

	/* check for existing interned string */
	idx = HT_HASH(&ZCSG(interned_strings), nIndex);
	arData = ZCSG(interned_strings).arData;
	while (idx != HT_INVALID_IDX) {
		p = HT_HASH_TO_BUCKET_EX(arData, idx);
		if ((p->h == h) && (ZSTR_LEN(p->key) == ZSTR_LEN(str))) {
			if (!memcmp(ZSTR_VAL(p->key), ZSTR_VAL(str), ZSTR_LEN(str))) {
				return p->key;
			}
		}
		idx = Z_NEXT(p->val);
	}

	return NULL;
}

it read shared memory, but I don't find read lock in function, because "opcache_rerest()" will execute "accel_interned_strings_restore_state()" function, it will write shared memory. I'm not an expert, so need your help,thanks!