[转]浏览器退出之后php还会继续执行么？，php继续执行

原文链接：http://www.cnblogs.com/yjf512/p/5362025.html

前提：这里说的是典型的lnmp结构，nginx+php-fpm的模式

如果我有个php程序执行地非常慢，甚至于在代码中sleep()，然后浏览器连接上服务的时候，会启动一个php-fpm进程，但是这个时候，如果浏览器关闭了，那么请问，这个时候服务端的这个php-fpm进程是否还会继续运行呢？

今天就是要解决这个问题。

最简单的实验

最简单的方法就是做实验，我们写一个程序：在sleep之前和之后都用file_put_contents来写入日志：

<code class="hljs cs"><?<span class="hljs-function">php
<span class="hljs-title">file_put_contents(<span class="hljs-params"><span class="hljs-string">'/tmp/test.log', <span class="hljs-string">'11111' . PHP_EOL, FILE_APPEND | LOCK_EX);
sleep(<span class="hljs-number">3);
file_put_contents(<span class="hljs-string">'/tmp/test.log', <span class="hljs-string">'2222' . PHP_EOL, FILE_APPEND | LOCK_EX);</span></span></span></span></span></span></span></span></code>

Salin selepas log masuk

实际操作的结果是，我们在服务器sleep的过程中，关闭客户端浏览器，2222是会被写入日志中。

那么就意味着浏览器关闭以后，服务端的php还是会继续运行的?

ignore_user_abort

老王和diogin提醒，这个可能是和php的ignore_user_abort函数相关。

于是我就把代码稍微改成这样的：

<code class="hljs cs"><?<span class="hljs-function">php
<span class="hljs-title">ignore_user_abort(<span class="hljs-params"><span class="hljs-keyword">false);
file_put_contents(<span class="hljs-string">'/tmp/test.log', <span class="hljs-string">'11111' . PHP_EOL, FILE_APPEND | LOCK_EX);
sleep(<span class="hljs-number">3);
file_put_contents(<span class="hljs-string">'/tmp/test.log', <span class="hljs-string">'2222' . PHP_EOL, FILE_APPEND | LOCK_EX);</span></span></span></span></span></span></span></span></span></code>

Salin selepas log masuk

发现并没有任何软用，不管设置ignore_user_abort为何值，都是会继续执行的。

但是这里有一个疑问: user_abort是什么？

文档对cli模式的abort说的很清楚，当php脚本执行的时候，用户终止了这个脚本的时候，就会触发abort了。然后脚本根据ignore_user_abort来判断是否要继续执行。

但是官方文档对cgi模式的abort并没有描述清楚。感觉即使客户端断开连接了，在cgi模式的php是不会收到abort的。
难道ignore_user_abort在cgi模式下是没有任何作用的？

是不是心跳问题呢？

首先想到的是不是心跳问题呢？我们断开浏览器客户端，等于在客户端没有close而断开了连接，服务端是需要等待tcp的keepalive到达时长之后才会检测出来的。

好，需要先排除浏览器设置的keepalive问题。

抛弃浏览器，简单写一个client程序：程序连接上http服务之后，发送一个header头，sleep1秒就主动close连接，而这个程序并没有带http的keepalive头。

程序如下：

<code class="hljs swift">package main

<span class="hljs-keyword">import "net"
<span class="hljs-keyword">import "fmt"
<span class="hljs-keyword">import "time"

<span class="hljs-function"><span class="hljs-keyword">func <span class="hljs-title">main<span class="hljs-params">() {
    conn, <span class="hljs-number">_ := net.<span class="hljs-type">Dial(<span class="hljs-string">"tcp", <span class="hljs-string">"192.168.33.10:10011")
    fmt.<span class="hljs-type">Fprintf(conn, <span class="hljs-string">"GET /index.php HTTP/1.0\r\n\r\n")
    time.<span class="hljs-type">Sleep(<span class="hljs-number">1 * time.<span class="hljs-type">Second)
    conn.<span class="hljs-type">Close()
    <span class="hljs-keyword">return
}</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></code>

Salin selepas log masuk

服务端程序：

<code class="hljs cs"><?<span class="hljs-function">php
<span class="hljs-title">ignore_user_abort(<span class="hljs-params"><span class="hljs-keyword">false);
file_put_contents(<span class="hljs-string">'/tmp/test.log', <span class="hljs-string">'11111' . PHP_EOL, FILE_APPEND | LOCK_EX);
sleep(<span class="hljs-number">3);
file_put_contents(<span class="hljs-string">'/tmp/test.log', <span class="hljs-string">'2222' . PHP_EOL, FILE_APPEND | LOCK_EX);</span></span></span></span></span></span></span></span></span></code>

Salin selepas log masuk

发现仍然还是一样，php还是不管是否设置ignore_user_abort，会继续执行完成整个脚本。看来ignore_user_abort还是没有生效。

如何触发ignore_user_abort

那该怎么触发ignore_user_abort呢？服务端这边怎么知晓这个socket不能使用了呢？老王和diogin说是不是需要服务端主动和socket进行交互，才会判断出这个socket是否可以使用？

另外，我们还发现，php提供了connection_status和connection_aborted两个方法，这两个方法都能检测出当前的连接状态。于是我们的打日志的那行代码就可以改成：

<code class="hljs lisp">file_put_contents('/tmp/test.log', '<span class="hljs-number">1 connection status: ' . connection_status() . <span class="hljs-string">"abort:" . connection_aborted() . PHP_EOL, FILE_APPEND | LOCK_EX)<span class="hljs-comment">;</span></span></span></code>

Salin selepas log masuk

根据手册连接处理显示我们可以打印出当前连接的状态了。

下面还缺少一个和socket交互的程序，我们使用echo，后面也顺带记得带上flush，排除了flush的影响。

程序就改成：

<code class="hljs django"><span class="xml"><span class="php"><span class="hljs-meta"><?php
ignore_user_abort(<span class="hljs-keyword">true);
file_put_contents(<span class="hljs-string">'/tmp/test.log', <span class="hljs-string">'1 connection status: ' . connection_status() . <span class="hljs-string">"abort:" . connection_aborted() . PHP_EOL, FILE_APPEND | LOCK_EX);

sleep(<span class="hljs-number">3);

<span class="hljs-keyword">for($i = <span class="hljs-number">0; $i < <span class="hljs-number">10; $i++) {
        <span class="hljs-keyword">echo <span class="hljs-string">"22222";
        flush();
        sleep(<span class="hljs-number">1);
        file_put_contents(<span class="hljs-string">'/tmp/test.log', <span class="hljs-string">'2 connection status: ' . connection_status() . <span class="hljs-string">"abort:" . connection_aborted(). PHP_EOL, FILE_APPEND | LOCK_EX);
}</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></code>

Salin selepas log masuk

很好，执行我们前面写的client。观察日志：

<code class="hljs basic"><span class="hljs-symbol">1 connection status: <span class="hljs-number">0abort:<span class="hljs-number">0
<span class="hljs-symbol">2 connection status: <span class="hljs-number">0abort:<span class="hljs-number">0
<span class="hljs-symbol">2 connection status: <span class="hljs-number">1abort:<span class="hljs-number">1
<span class="hljs-symbol">2 connection status: <span class="hljs-number">1abort:<span class="hljs-number">1
<span class="hljs-symbol">2 connection status: <span class="hljs-number">1abort:<span class="hljs-number">1
<span class="hljs-symbol">2 connection status: <span class="hljs-number">1abort:<span class="hljs-number">1
<span class="hljs-symbol">2 connection status: <span class="hljs-number">1abort:<span class="hljs-number">1
<span class="hljs-symbol">2 connection status: <span class="hljs-number">1abort:<span class="hljs-number">1
<span class="hljs-symbol">2 connection status: <span class="hljs-number">1abort:<span class="hljs-number">1
<span class="hljs-symbol">2 connection status: <span class="hljs-number">1abort:<span class="hljs-number">1
<span class="hljs-symbol">2 connection status: <span class="hljs-number">1abort:<span class="hljs-number">1</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></code>

Salin selepas log masuk

终于制造出了abort。日志也显示后面几次的abort状态都是1。

但是这里有个奇怪的地方，为什么第一个2 connection status的状态还是0呢（NORMAL）。

RST

我们使用wireshark抓包看整个客户端和服务端交互的过程

这整个过程只有发送14个包，我们看下服务端第一次发送22222的时候，客户端返回的是RST。后面就没有进行后续的包请求了。

于是理解了，客户端和服务端大概的交互流程是：

当服务端在循环中第一次发送2222的时候，客户端由于已经断开连接了，返回的是一个RST，但是这个发送过程算是请求成功了。直到第二次服务端再次想往这个socket中进行write操作的时候，这个socket就不进行网络传输了，直接返回说connection的状态已经为abort。所以就出现了上面的情况，第一次222是status为0，第二次的时候才出现abort。

strace进行验证

我们也可以使用strace php -S XXX来进行验证

整个过程strace的日志如下：

<code class="hljs erlang">。。。
<span class="hljs-function"><span class="hljs-title">close<span class="hljs-params">(<span class="hljs-number">5)                                = 0
<span class="hljs-title">lstat<span class="hljs-params">(<span class="hljs-string">"/tmp/test.log", {st_mode=S_IFREG|<span class="hljs-number">0644, st_size=<span class="hljs-number">49873651, ...}) = 0
<span class="hljs-title">open<span class="hljs-params">(<span class="hljs-string">"/tmp/test.log", O_WRONLY|O_CREAT|O_APPEND, <span class="hljs-number">0666) = 5
<span class="hljs-title">fstat<span class="hljs-params">(<span class="hljs-number">5, {st_mode=S_IFREG|<span class="hljs-number">0644, st_size=<span class="hljs-number">49873651, ...}) = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">flock<span class="hljs-params">(<span class="hljs-number">5, LOCK_EX)                       = 0
<span class="hljs-title">write<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-string">"1 connection status: 0abort:0\n", <span class="hljs-number">30) = 30
<span class="hljs-title">close<span class="hljs-params">(<span class="hljs-number">5)                                = 0
<span class="hljs-title">sendto<span class="hljs-params">(<span class="hljs-number">4, <span class="hljs-string">"HTTP/1.0 200 OK\r\nConnection: clo"..., <span class="hljs-number">89, <span class="hljs-number">0, NULL, <span class="hljs-number">0) = 89
<span class="hljs-title">sendto<span class="hljs-params">(<span class="hljs-number">4, <span class="hljs-string">"111111111", <span class="hljs-number">9, <span class="hljs-number">0, NULL, <span class="hljs-number">0)   = 9
<span class="hljs-title">rt_sigprocmask<span class="hljs-params">(SIG_BLOCK, [CHLD], [], <span class="hljs-number">8) = 0
<span class="hljs-title">rt_sigaction<span class="hljs-params">(SIGCHLD, NULL, {SIG_DFL, [], <span class="hljs-number">0}, <span class="hljs-number">8) = 0
<span class="hljs-title">rt_sigprocmask<span class="hljs-params">(SIG_SETMASK, [], NULL, <span class="hljs-number">8) = 0
<span class="hljs-title">nanosleep<span class="hljs-params">({<span class="hljs-number">3, <span class="hljs-number">0}, <span class="hljs-number">0x7fff60a40290)       = 0
<span class="hljs-title">sendto<span class="hljs-params">(<span class="hljs-number">4, <span class="hljs-string">"22222", <span class="hljs-number">5, <span class="hljs-number">0, NULL, <span class="hljs-number">0)       = 5
<span class="hljs-title">open<span class="hljs-params">(<span class="hljs-string">"/tmp/test.log", O_WRONLY|O_CREAT|O_APPEND, <span class="hljs-number">0666) = 5
<span class="hljs-title">fstat<span class="hljs-params">(<span class="hljs-number">5, {st_mode=S_IFREG|<span class="hljs-number">0644, st_size=<span class="hljs-number">49873681, ...}) = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">flock<span class="hljs-params">(<span class="hljs-number">5, LOCK_EX)                       = 0
<span class="hljs-title">write<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-string">"2 connection status: 0abort:0\n", <span class="hljs-number">30) = 30
<span class="hljs-title">close<span class="hljs-params">(<span class="hljs-number">5)                                = 0
<span class="hljs-title">rt_sigprocmask<span class="hljs-params">(SIG_BLOCK, [CHLD], [], <span class="hljs-number">8) = 0
<span class="hljs-title">rt_sigaction<span class="hljs-params">(SIGCHLD, NULL, {SIG_DFL, [], <span class="hljs-number">0}, <span class="hljs-number">8) = 0
<span class="hljs-title">rt_sigprocmask<span class="hljs-params">(SIG_SETMASK, [], NULL, <span class="hljs-number">8) = 0
<span class="hljs-title">nanosleep<span class="hljs-params">({<span class="hljs-number">1, <span class="hljs-number">0}, <span class="hljs-number">0x7fff60a40290)       = 0
<span class="hljs-title">sendto<span class="hljs-params">(<span class="hljs-number">4, <span class="hljs-string">"22222", <span class="hljs-number">5, <span class="hljs-number">0, NULL, <span class="hljs-number">0)       = -1 EPIPE <span class="hljs-params">(Broken pipe)
--- SIGPIPE {<span class="hljs-title">si_signo=SIGPIPE, <span class="hljs-title">si_code=SI_USER, <span class="hljs-title">si_pid=2819, <span class="hljs-title">si_uid=0} ---
<span class="hljs-title">open<span class="hljs-params">(<span class="hljs-string">"/tmp/test.log", O_WRONLY|O_CREAT|O_APPEND, <span class="hljs-number">0666) = 5
<span class="hljs-title">fstat<span class="hljs-params">(<span class="hljs-number">5, {st_mode=S_IFREG|<span class="hljs-number">0644, st_size=<span class="hljs-number">49873711, ...}) = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">flock<span class="hljs-params">(<span class="hljs-number">5, LOCK_EX)                       = 0
<span class="hljs-title">write<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-string">"2 connection status: 1abort:1\n", <span class="hljs-number">30) = 30
<span class="hljs-title">close<span class="hljs-params">(<span class="hljs-number">5)                                = 0
<span class="hljs-title">rt_sigprocmask<span class="hljs-params">(SIG_BLOCK, [CHLD], [], <span class="hljs-number">8) = 0
<span class="hljs-title">rt_sigaction<span class="hljs-params">(SIGCHLD, NULL, {SIG_DFL, [], <span class="hljs-number">0}, <span class="hljs-number">8) = 0
<span class="hljs-title">rt_sigprocmask<span class="hljs-params">(SIG_SETMASK, [], NULL, <span class="hljs-number">8) = 0
<span class="hljs-title">nanosleep<span class="hljs-params">({<span class="hljs-number">1, <span class="hljs-number">0}, <span class="hljs-number">0x7fff60a40290)       = 0
<span class="hljs-title">open<span class="hljs-params">(<span class="hljs-string">"/tmp/test.log", O_WRONLY|O_CREAT|O_APPEND, <span class="hljs-number">0666) = 5
<span class="hljs-title">fstat<span class="hljs-params">(<span class="hljs-number">5, {st_mode=S_IFREG|<span class="hljs-number">0644, st_size=<span class="hljs-number">49873741, ...}) = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">flock<span class="hljs-params">(<span class="hljs-number">5, LOCK_EX)                       = 0
<span class="hljs-title">write<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-string">"2 connection status: 1abort:1\n", <span class="hljs-number">30) = 30
<span class="hljs-title">close<span class="hljs-params">(5)  
。。。</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></code>

Salin selepas log masuk

我们照中看status从0到1转变的地方。

<code class="hljs erlang">...
<span class="hljs-function"><span class="hljs-title">sendto<span class="hljs-params">(<span class="hljs-number">4, <span class="hljs-string">"22222", <span class="hljs-number">5, <span class="hljs-number">0, NULL, <span class="hljs-number">0)       = 5
...
<span class="hljs-title">write<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-string">"2 connection status: 0abort:0\n", <span class="hljs-number">30) = 30
<span class="hljs-title">close<span class="hljs-params">(<span class="hljs-number">5)                                = 0
<span class="hljs-title">rt_sigprocmask<span class="hljs-params">(SIG_BLOCK, [CHLD], [], <span class="hljs-number">8) = 0
<span class="hljs-title">rt_sigaction<span class="hljs-params">(SIGCHLD, NULL, {SIG_DFL, [], <span class="hljs-number">0}, <span class="hljs-number">8) = 0
<span class="hljs-title">rt_sigprocmask<span class="hljs-params">(SIG_SETMASK, [], NULL, <span class="hljs-number">8) = 0
<span class="hljs-title">nanosleep<span class="hljs-params">({<span class="hljs-number">1, <span class="hljs-number">0}, <span class="hljs-number">0x7fff60a40290)       = 0
<span class="hljs-title">sendto<span class="hljs-params">(<span class="hljs-number">4, <span class="hljs-string">"22222", <span class="hljs-number">5, <span class="hljs-number">0, NULL, <span class="hljs-number">0)       = -1 EPIPE <span class="hljs-params">(Broken pipe)
--- SIGPIPE {<span class="hljs-title">si_signo=SIGPIPE, <span class="hljs-title">si_code=SI_USER, <span class="hljs-title">si_pid=2819, <span class="hljs-title">si_uid=0} ---
<span class="hljs-title">open<span class="hljs-params">(<span class="hljs-string">"/tmp/test.log", O_WRONLY|O_CREAT|O_APPEND, <span class="hljs-number">0666) = 5
<span class="hljs-title">fstat<span class="hljs-params">(<span class="hljs-number">5, {st_mode=S_IFREG|<span class="hljs-number">0644, st_size=<span class="hljs-number">49873711, ...}) = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">lseek<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-number">0, SEEK_CUR)                   = 0
<span class="hljs-title">flock<span class="hljs-params">(<span class="hljs-number">5, LOCK_EX)                       = 0
<span class="hljs-title">write<span class="hljs-params">(<span class="hljs-number">5, <span class="hljs-string">"2 connection status: 1abort:1\n", <span class="hljs-number">30) = 30
<span class="hljs-title">close<span class="hljs-params">(<span class="hljs-number">5)                                = 0</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></code>

Salin selepas log masuk

第二次往socket中发送2222的时候显示了Broken pipe。这就是程序告诉我们，这个socket已经不能使用了，顺便php中的connection_status就会被设置为1了。后续的写操作也都不会再执行了。