(PHP 4 >= 4.3.0, PHP 5)
msg_receive — Receive a message from a message queue
$queue
, int $desiredmsgtype
, int &$msgtype
, int $maxsize
, mixed &$message
[, bool $unserialize = true
[, int $flags = 0
[, int &$errorcode
]]] )
msg_receive() will receive the first message from the
specified queue of the type specified by
desiredmsgtype.
queue
desiredmsgtype
If desiredmsgtype is 0, the message from the front
of the queue is returned. If desiredmsgtype is
greater than 0, then the first message of that type is returned.
If desiredmsgtype is less than 0, the first
message on the queue with the lowest type less than or equal to the
absolute value of desiredmsgtype will be read.
If no messages match the criteria, your script will wait until a suitable
message arrives on the queue. You can prevent the script from blocking
by specifying MSG_IPC_NOWAIT in the
flags parameter.
msgtype
The type of the message that was received will be stored in this parameter.
maxsize
The maximum size of message to be accepted is specified by the
maxsize; if the message in the queue is larger
than this size the function will fail (unless you set
flags as described below).
message
The received message will be stored in message,
unless there were errors receiving the message.
unserialize
If set to
TRUE, the message is treated as though it was serialized using the
same mechanism as the session module. The message will be unserialized
and then returned to your script. This allows you to easily receive
arrays or complex object structures from other PHP scripts, or if you
are using the WDDX serializer, from any WDDX compatible source.
If unserialize is FALSE, the message will be
returned as a binary-safe string.
flags
The optional flags allows you to pass flags to the
low-level msgrcv system call. It defaults to 0, but you may specify one
or more of the following values (by adding or ORing them together).
MSG_IPC_NOWAIT |
If there are no messages of the
desiredmsgtype, return immediately and do not
wait. The function will fail and return an integer value
corresponding to MSG_ENOMSG.
|
MSG_EXCEPT |
Using this flag in combination with a
desiredmsgtype greater than 0 will cause the
function to receive the first message that is not equal to
desiredmsgtype. |
MSG_NOERROR |
If the message is longer than maxsize,
setting this flag will truncate the message to
maxsize and will not signal an error.
|
errorcode
If the function fails, the optional errorcode
will be set to the value of the system errno variable.
成功时返回 TRUE， 或者在失败时返回 FALSE。
Upon successful completion the message queue data structure is updated as follows: msg_lrpid is set to the process-ID of the calling process, msg_qnum is decremented by 1 and msg_rtime is set to the current time.