streamWrapper::stream_lock
(PHP 5, PHP 7)
streamWrapper::stream_lock — Advisory file locking
说明
public
streamWrapper::stream_lock (
int
$operation
) :
bool
This method is called in response to flock(), when file_put_contents() (when flags
contains LOCK_EX
), stream_set_blocking() and when closing the stream (LOCK_UN
).
参数
-
operation
-
operation
is one of the following:-
LOCK_SH
to acquire a shared lock (reader). -
LOCK_EX
to acquire an exclusive lock (writer). -
LOCK_UN
to release a lock (shared or exclusive). -
LOCK_NB
if you don't want flock() to block while locking. (not supported on Windows)
-
返回值
成功时返回 TRUE
, 或者在失败时返回 FALSE
。
错误/异常
Emits E_WARNING
if call to this method fails (i.e. not implemented).