add signal example

examples/thread/signal.php

@@ -0,0 +1,36 @@
+<?php
+
+use Swoole\Thread;
+use Swoole\Coroutine\System;
+
+$args = Thread::getArguments();
+
+if (empty($args)) {
+    Co\run(function () {
+        echo "main thread\n";
+        $sockets = swoole_coroutine_socketpair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP);
+        $thread = Thread::exec(__FILE__, $sockets);
+        $parent_pipe = $sockets[1];
+        // 收到信号之后向子线程发送指令让子线程退出
+        if (System::waitSignal(SIGTERM)) {
+            echo "signal term\n";
+            $parent_pipe->send('exit');
+        }
+        Co\go(function () use ($parent_pipe, $thread) {
+            // 从管道中读取子线程退出的信息
+            echo $parent_pipe->recv(8192), PHP_EOL;
+            // 回收子线程
+            $thread->join();
+        });
+    });
+} else {
+    echo "child thread\n";
+    $sockets = $args[0];
+    $child_pipe = $sockets[0];
+    Co\run(function () use ($child_pipe) {
+        // 收到父线程的指令，开始退出
+        echo $child_pipe->recv(8192), PHP_EOL;
+        // 通知父线程已退出
+        $child_pipe->send('child exit');
+    });
+}