<?php
define('CONFIG_FILE', __DIR__ . '/config.php');
define('LOG_NAME', 'transfer2');
define('MSG_MAX_SIZE', 1024);

include __DIR__ . '/functions.php';
include __DIR__ . '/class.async.php';

//检查参数
if ($argc < 2) {
	die("Usage: {$argv[0]} TRANSFER_ID\n");
}

//加载配置
$cfg = [];
load_config();
$transferId = intval($argv[1]); //进程的编号
$queueKey = intval($cfg['sysvmsg_key']); //消息队列的KEY

//保障只运行一个进程
$lockFile = run_single_instance($transferId);

//创建队列
$q = msg_get_queue($queueKey, 0666);
if (!$q) {
	die("msg_get_queue() failed!\n");
}

//创建子进程
$parentId = getmypid();
$childPid = create_child_process($parentId, $q, $cfg['timeout']);

//修改进程名称
cli_set_process_title('php -f ' . implode(' ', $argv) . ' [master]');

//设置信号处理函数(在子进程创建之后才设置信号处理函数)
$quit = $restart = false;
$async = null;
pcntl_signal(SIGTERM, 'sig_handle'); //quit
pcntl_signal(SIGUSR1, 'sig_handle'); //restart
pcntl_signal(SIGUSR2, 'sig_handle'); //ping
pcntl_signal(SIGCHLD, 'sig_handle'); //child quit

//从队列中取消息
try {
	$async = new Async($cfg['redis_host'], $cfg['redis_port'], $cfg['worker_num']);
	debug_log("Transfer#{$transferId} started, pid = " . getmypid(), 'DEBUG', LOG_NAME);
	$flag = false;
	while (1) {
		declare (ticks = 1) {
			$flag = msg_receive($q, 0, $msgtype, MSG_MAX_SIZE, $msg, false, 0, $errcode);
		}
		if ($flag) {
			$data = json_decode($msg, true);
			if (!$data || !is_array($data) || count($data) < 1) {
				continue;
			}
			$async->pushJob($data);
		} else {
			if ($quit) {
				debug_log("Transfer#{$transferId} quiting", 'WARNING', LOG_NAME);
				unlink($lockFile);
				if (kill_child_process($transferId, $childPid)) { //先杀子进程
					exit(0);
				} else {
					debug_log("Transfer#{$transferId} quit failed", 'ERROR', LOG_NAME);
					exit(1);
				}
			} elseif ($restart) {
				debug_log("Transfer#{$transferId} restarting", 'WARNING', LOG_NAME);
				unlink($lockFile);
				if (kill_child_process($transferId, $childPid)) { //先杀子进程
					pcntl_exec($cfg['php_bin_path'], $argv);
				}
				debug_log("Transfer#{$transferId} restart failed", 'ERROR', LOG_NAME);
				exit(1);
			} else {
				$async->ping();
			}
		}
	}
} catch (RedisException $e) {
	debug_log("Transfer#{$transferId} catched an RedisException:" . $e->getMessage(), 'EXCEPTION', LOG_NAME);
}

/**
 * 信号处理函数
 * @param int $signo 信号值
 */
function sig_handle($signo)
{
	global $cfg, $q, $parentId, $childPid, $quit, $restart;
	switch ($signo) {
		//退出
		case SIGTERM:
			$quit = true;
			pcntl_sigprocmask(SIG_BLOCK, [SIGTERM, SIGUSR1, SIGUSR2, SIGCHLD]);
			break;
		//重启
		case SIGUSR1:
			$restart = true;
			pcntl_sigprocmask(SIG_BLOCK, [SIGTERM, SIGUSR1, SIGUSR2, SIGCHLD]);
			break;
		//保持连接
		case SIGUSR2:
			break;
		//子进程退出
		case SIGCHLD:
			if (!$quit && pcntl_waitpid($childPid, $status, WNOHANG) == $childPid) {
				$childPid = create_child_process($parentId, $q, $cfg['timeout']);
			}
			break;
	}
}

/**
 * 创建子进程
 * @param int $ppid 父进程的ID
 * @param resource $queue 消息队列的资源ID
 * @param int $timeout SLEEP的时间
 * @return int 子进程ID
 */
function create_child_process($ppid, $queue, $timeout)
{
	global $async;

	$pid = pcntl_fork();
	//创建失败
	if ($pid < 0) {
		die("pcntl_fork() failed!\n");
	}
	//父进程
	if ($pid > 0) {
		return $pid;
	}
	//子进程的主循环
	pcntl_signal(SIGTERM, SIG_DFL); //quit
	pcntl_signal(SIGUSR1, SIG_DFL); //restart
	pcntl_signal(SIGUSR2, SIG_DFL); //ping
	pcntl_signal(SIGCHLD, SIG_DFL); //child quit
	cli_set_process_title('php -f ' . implode(' ', $_SERVER['argv']) . ' [timer]');
	if ($async) {
		unset($async);
	}
	while (1) {
		sleep($timeout);
		posix_kill($ppid, SIGUSR2);
	}
	exit(0);
}

/**
 * 杀死子进程
 * @param int $pid 子进程ID
 * @return bool 是否成功
 */
function kill_child_process($transferId, $pid)
{
	if (!posix_kill($pid, SIGTERM)) {
		debug_log("Transfer#{$transferId} posix_kill({$pid}) failed", 'ERROR', LOG_NAME);
		return false;
	}
	$returnPid = pcntl_waitpid($pid, $status);
	if ($returnPid != $pid) {
		debug_log("Transfer#{$transferId} pcntl_waitpid({$pid}) call failed, return value = {$returnPid}", 'ERROR', LOG_NAME);
		return false;
	}
	return true;
}