<?php
$message_queue_key = ftok(__FILE__, 'a');
$message_queue = msg_get_queue($message_queue_key, 0666);
var_dump($message_queue);
$message_queue_status = msg_stat_queue($message_queue);
print_r($message_queue_status);
//向消息隊列中寫
msg_send($message_queue, 1, "Hello,World!");
$message_queue_status = msg_stat_queue($message_queue);
print_r($message_queue_status);
//從消息隊列中讀
msg_receive($message_queue, 0, $message_type, 1024, $message, true, MSG_IPC_NOWAIT);
print_r($message."\r\n");
msg_remove_queue($message_queue);
?>

resource(4) of type (sysvmsg queue)
Array
(
[msg_perm.uid] => 1000
[msg_perm.gid] => 1000
[msg_perm.mode] => 438
[msg_stime] => 0
[msg_rtime] => 0
[msg_ctime] => 1279849495
[msg_qnum] => 0
[msg_qbytes] => 16384
[msg_lspid] => 0
[msg_lrpid] => 0
)
Array
(
[msg_perm.uid] => 1000
[msg_perm.gid] => 1000
[msg_perm.mode] => 438
[msg_stime] => 1279849495
[msg_rtime] => 0
[msg_ctime] => 1279849495
[msg_qnum] => 1
[msg_qbytes] => 16384
[msg_lspid] => 2184
[msg_lrpid] => 0
)
Hello,World!

ftok ( string $pathname , string $proj )
手冊上給出的解釋是：Convert a pathname and a project identifier to a System V IPC key。這個函數(shù)返回的鍵值唯一對應(yīng)linux系統(tǒng)中一個消息隊列。在獲得消息隊列的引用之前都需要調(diào)用這個函數(shù)。
msg_get_queue ( int $key [, int $perms ] )
msg_get_queue()會根據(jù)傳入的鍵值返回一個消息隊列的引用。如果linux系統(tǒng)中沒有消息隊列與鍵值對應(yīng)，msg_get_queue()將會創(chuàng)建一個新的消息隊列。函數(shù)的第二個參數(shù)需要傳入一個int值，作為新創(chuàng)建的消息隊列的權(quán)限值，默認(rèn)為0666。這個權(quán)限值與linux命令chmod中使用的數(shù)值是同一個意思，因為在linux系統(tǒng)中一切皆是文件。
msg_send ( resource $queue , int $msgtype , mixed $message [, bool $serialize [, bool $blocking [, int &$errorcode ]]] )
顧名思義，該函數(shù)用來向消息隊列中寫數(shù)據(jù)。
msg_stat_queue ( resource $queue )
這個函數(shù)會返回消息隊列的元數(shù)據(jù)。消息隊列元數(shù)據(jù)中的信息很完整，包括了消息隊列中待讀取的消息數(shù)、最后讀寫隊列的進程ID等。示例代碼在第8行調(diào)用該函數(shù)返回的數(shù)組中隊列中待讀取的消息數(shù)msg_qnum值為0。
msg_receive ( resource $queue , int $desiredmsgtype , int &$msgtype , int $maxsize , mixed &$message [, bool $unserialize [, int $flags [, int &$errorcode ]]] )
msg_receive用于讀取消息隊列中的數(shù)據(jù)。
msg_remove_queue ( resource $queue )
msg_remove_queue用于銷毀一個隊列。

<?php
$message_queue_key = ftok(__FILE__, 'a');
$message_queue = msg_get_queue($message_queue_key, 0666);
$pids = array();
for ($i = 0; $i < 5; $i++) {
//創(chuàng)建子進程
$pids[$i] = pcntl_fork();
if ($pids[$i]) {
echo "No.$i child process was created, the pid is $pids[$i]\r\n";
} elseif ($pids[$i] == 0) {
$pid = posix_getpid();
echo "process.$pid is writing now\r\n";
msg_send($message_queue, 1, "this is process.$pid's data\r\n");
posix_kill($pid, SIGTERM);
}
}
do {
msg_receive($message_queue, 0, $message_type, 1024, $message, true, MSG_IPC_NOWAIT);
echo $message;
//需要判斷隊列是否為空，如果為空就退出
//break;
} while(true)
?>

No.0 child process was created, the pid is 5249
No.1 child process was created, the pid is 5250
No.2 child process was created, the pid is 5251
No.3 child process was created, the pid is 5252
No.4 child process was created, the pid is 5253
process.5251 is writing now
this is process.5251's data
process.5253 is writing now
process.5252 is writing now
process.5250 is writing now
this is process.5253's data
this is process.5252's data
this is process.5250's data
process.5249 is writing now
this is process.5249's data