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关于Linux系统进程通信的概念及实现可查看：http://www.ibm.com/developerworks/cn/linux/l-ipc/ 关于Linux系统消息队列的概念及实现可查看：http://www.ibm.com/developerworks/cn/linux/l-ipc/part4/ 复制代码 代码如下: $message_queue = msg_get_queue($message_queue_key, 0666); var_dump($message_queue); $message_queue_status = msg_stat_queue($message_queue); print_r($message_queue_status); //向消息队列中写 msg_send($message_queue, 1, "Hello,World!"); $message_queue_status = msg_stat_queue($message_queue); print_r($message_queue_status); //从消息队列中读 msg_receive($message_queue, 0, $message_type, 1024, $message, true, MSG_IPC_NOWAIT); print_r($message."\r\n"); msg_remove_queue($message_queue); ?> 这段代码的运行结果如下： 复制代码 代码如下: 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! 可以看到已成功从消息队列中读取“Hello,World!”字符串 下面列举一下示例代码中的主要函数： 复制代码 代码如下: ftok ( string $pathname , string $proj ) 手册上给出的解释是：Convert a pathname and a project identifier to a System V IPC key。这个函数返回的键值唯一对应linux系统中一个消息队列。在获得消息队列的引用之前都需要调用这个函数。 msg_get_queue ( int $key [, int $perms ] ) msg_get_queue()会根据传入的键值返回一个消息队列的引用。如果linux系统中没有消息队列与键值对应，msg_get_queue()将会创建一个新的消息队列。函数的第二个参数需要传入一个int值，作为新创建的消息队列的权限值，默认为0666。这个权限值与linux命令chmod中使用的数值是同一个意思，因为在linux系统中一切皆是文件。 msg_send ( resource $queue , int $msgtype , mixed $message [, bool $serialize [, bool $blocking [, int &$errorcode ]]] ) 顾名思义，该函数用来向消息队列中写数据。 msg_stat_queue ( resource $queue ) 这个函数会返回消息队列的元数据。消息队列元数据中的信息很完整，包括了消息队列中待读取的消息数、最后读写队列的进程ID等。示例代码在第8行调用该函数返回的数组中队列中待读取的消息数msg_qnum值为0。 msg_receive ( resource $queue , int $desiredmsgtype , int &$msgtype , int $maxsize , mixed &$message [, bool $unserialize [, int $flags [, int &$errorcode ]]] ) msg_receive用于读取消息队列中的数据。 msg_remove_queue ( resource $queue ) msg_remove_queue用于销毁一个队列。 示例代码_1只是展示了复制代码 代码如下: $message_queue = msg_get_queue($message_queue_key, 0666); $pids = array(); for ($i = 0; $i //创建子进程 $pids[$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; //需要判断队列是否为空，如果为空就退出 //break; } while(true) ?> 运行结果为： 复制代码 代码如下: 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 这段程序每次的运行结果都会不同，这正说明了多进程的异步性。从结果也能看出消息队列FIFO特性。 以上便是我研究的一点心得。接下来将会继续研究 09-17 08:37