在除了函数原型之外没有任何文档的情况下,我很难找到mysqli_poll()函数的第三个参数是什么。
int mysqli_poll (
array &$read ,
array &$error ,
array &$reject ,
int $sec
[, int $usec ] )
查看(C)源代码,它似乎用资源填充$reject数组,其中。。。
CONN_GET_STATE((*p)->data) <= CONN_READY
|| CONN_GET_STATE((*p)->data) == CONN_QUIT_SENT
这是否意味着与服务器的连接正在关闭?
还有别的吗?
是否应该预先配置资源来检查断开连接?或者它们将从$read和$error自动添加?
数组绑定到select()系统调用。
如您所见:http://lxr.php.net/xref/PHP_5_5/ext/mysqlnd/mysqlnd.c#1384
所以,是的,根据select(2)
man文档:
Select()检查其地址在readfds、writefds和errorfds中传递的I/O描述符集,以查看它们的某些描述符是否分别准备好读取、准备好写入或具有挂起的异常条件。
(writefds
在这里并不重要,在实现中被忽略)
如果$read
或$error
数组中的另一个填充了mysqli对象,则允许它们为空。
$read
必须是一个包含要轮询的mysqli对象的数组。
$error
必须是一个包含mysqli对象的数组,您希望检查异常数据。
正如你从中看到的http://lxr.php.net/xref/PHP_5_5/ext/mysqlnd/mysqlnd_enum_n_def.h#322和http://lxr.php.net/xref/PHP_5_5/ext/mysqlnd/mysqlnd.c#1228,与<= CONN_READY || == CONN_QUIT_SENT
不匹配的所有内容都意味着CONN_QUERY_SENT, CONN_SENDING_LOAD_DATA, CONN_FETCHING_DATA, CONN_NEXT_RESULT_PENDING
(即数据尚未准备好提取;名称应自行解释)将不会添加到准备好的数组==将是$rejected
:
当您将$rejected
传递给函数时,它可以是任何东西;它将被一个数组覆盖,该数组包含CCD_ 11中尚未准备好读取的条目。
我相信这就是被拒绝的线程的结局。
请参见此示例:https://svn.osgeo.org/mapguide/sandbox/rfc94/Oem/php/ext/mysqli/tests/mysqli_poll.phpt
我建造了一个测试装置:
$l1 = mysqli_connect();
$l2 = mysqli_connect();
$l3 = mysqli_connect();
$s1 = "SELECT CURTIME()";
$s2 = "SELECT * FROM"; // will error #1064
$s3 = "SELECT SLEEP(10), CURTIME()";
mysqli_query($l1, $s1, MYSQLI_ASYNC);
mysqli_query($l2, $s2, MYSQLI_ASYNC);
mysqli_query($l3, $s3, MYSQLI_ASYNC);
$started=time();
for ($x=0; $x<5; $x++) {
$ready=$reject=$errors = array($l1, $l2, $l3);
print "'niteration $x at t+" . (time()-$started) . "'n";
mysqli_poll($ready, $errors, $reject, 3);
print "ready = " . count($ready) . "'n";
foreach($ready as $r) {
$c=mysqli_reap_async_query($r);
print "err=" . mysqli_error($r) . " cnt=" . count($c) . "'n";
};
print "errors = " . count($errors) . "'n";
print "reject = " . count($reject) . "'n";
sleep(4);
}
结果(前缀为//的注释):
iteration 0 at t+0
ready = 1 // appears to be SELECT CURTIME()
err= cnt=1
errors = 0
reject = 0
iteration 1 at t+4
ready = 1 // appears to be SELECT * FROM
err=You have an error in your SQL syntax; check the manual that corresponds
to your MySQL server version for the right syntax to use near '' at line
1 cnt=1
errors = 0
reject = 1 // appears to be SELECT CURTIME() (results reaped)
iteration 2 at t+8
ready = 1 // appears to be SELECT SLEEP(10) despite 8 seconds elapsed
err= cnt=1
errors = 0
reject = 2 // appears to be SELECT CURTIME() + SELECT * FROM
iteration 3 at t+14
ready = 0
errors = 0
reject = 3
iteration 4 at t+21
ready = 0
errors = 0
reject = 3
即$reject被填充了已经获得结果的链接,而不是尚未准备好轮询的链接。
尝试使用无效连接,该值将从所有数组中删除(不添加到$reject),