新增《PHP扩展开发》-协程-修复一些bug（三）

README.md

@@ -44,3 +44,4 @@ PHP版本：7.3.5
 
 [19、协程isExist](./docs/《PHP扩展开发》-协程-协程isExist.md)
 
+[20、修复一些bug（三）](./docs/《PHP扩展开发》-协程-修复一些bug（三）.md)
\ No newline at end of file

docs/《PHP扩展开发》-协程-修复一些bug（三）.md

+# 修复一些bug（三）
+
+这篇文章，我们来修复一个`Study\Coroutine::getCid()`的bug。
+
+测试脚本如下：
+
+```php
+<?php
+
+$cid = Study\Coroutine::getCid();
+echo "coroutine [{$cid}] create" . PHP_EOL;
+```
+
+也就是说，我们在非协程环境下调用了`Study\Coroutine::getCid()`。
+
+我们来执行脚本：
+
+```shell
+~/codeDir/cppCode/study # php test.php 
+Segmentation fault
+~/codeDir/cppCode/study # 
+```
+
+报错了。
+
+我们来调试一下：
+
+```shell
+~/codeDir/cppCode/study # cgdb php
+GNU gdb (GDB) 8.2
+Copyright (C) 2018 Free Software Foundation, Inc.
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
+This is free software: you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law.
+Type "show copying" and "show warranty" for details.
+This GDB was configured as "x86_64-alpine-linux-musl".
+Type "show configuration" for configuration details.
+For bug reporting instructions, please see:
+<http://www.gnu.org/software/gdb/bugs/>.
+Find the GDB manual and other documentation resources online at:
+    <http://www.gnu.org/software/gdb/documentation/>.
+
+For help, type "help".
+Type "apropos word" to search for commands related to "word"...
+Reading symbols from php...(no debugging symbols found)...done.
+(gdb) 
+```
+
+然后执行脚本：
+
+```shell
+13│ public:
+14│     static std::unordered_map<long, Coroutine*> coroutines;
+15│
+16│     static void* get_current_task();
+17│     static long create(coroutine_func_t fn, void* args = nullptr);
+18│     void* get_task();
+19│     static Coroutine* get_current();
+20│     void set_task(void *_task);
+21│     void yield();
+22│     void resume();
+23│
+24│     inline long get_cid()
+25│     {
+26├─666666> return cid;
+27│     }
+```
+
+是在调用`Study::Coroutine::get_cid()`的时候报错的。
+
+我们在`zim_study_coroutine_util_getCid`处打一个断点：
+
+```shell
+(gdb) b zim_study_coroutine_util_getCid
+Breakpoint 1 at 0x7ffff78d1f73: file /root/codeDir/cppCode/study/study_coroutine_util.cc, line 71.
+(gdb) 
+```
+
+然后重新运行脚本：
+
+```shell
+(gdb) r test.php 
+The program being debugged has been started already.
+Start it from the beginning? (y or n) y
+The program being debugged has been started already.
+Starting program: /usr/local/bin/php test.php
+
+Breakpoint 1, zim_study_coroutine_util_getCid (execute_data=0x7ffff761d0f0, return_value=0x7ffff761d090) at /root/codeDir/cppCode/study/study_coroutine_util.cc:71
+(gdb) 
+```
+
+```cpp
+ 69│ PHP_METHOD(study_coroutine_util, getCid)
+ 70│ {
+ 71├───> Coroutine* co = Coroutine::get_current();
+ 72│     RETURN_LONG(co->get_cid());
+ 73│ }
+```
+
+继续：
+
+```shell
+(gdb) n
+(gdb) 
+```
+
+```cpp
+ 69│ PHP_METHOD(study_coroutine_util, getCid)
+ 70│ {
+ 71│     Coroutine* co = Coroutine::get_current();
+ 72├───> RETURN_LONG(co->get_cid());
+ 73│ }
+```
+
+打印一下这个`co`：
+
+```shell
+(gdb) p co
+$1 = (Study::Coroutine *) 0x0
+(gdb) 
+```
+
+我们发现，因为我们的`Study::Coroutine::current`在初始化的时候，给了初始值：
+
+```cpp
+Coroutine* Coroutine::current = nullptr;
+```
+
+所以，当然是`0x0`了。因此我们无法调用`get_cid()`。
+
+所以，我们只需要判断一下`Coroutine* co = Coroutine::get_current();`取出来的`co`是否为`nullptr`即可修复这个bug：
+
+```cpp
+Coroutine* co = Coroutine::get_current();
+if (co == nullptr)
+{
+  	RETURN_LONG(-1);
+}
+RETURN_LONG(co->get_cid());
+```
+
+OK，我们编译、安装：
+
+```shell
+~/codeDir/cppCode/study # make clean && make && make install
+----------------------------------------------------------------------
+
+Build complete.
+Don't forget to run 'make test'.
+
+Installing shared extensions:     /usr/local/lib/php/extensions/no-debug-non-zts-20180731/
+Installing header files:          /usr/local/include/php/
+```
+
+执行脚本：
+
+```shell
+~/codeDir/cppCode/study # php test.php 
+coroutine [-1] create
+~/codeDir/cppCode/study # 
+```
+
+符合预期。
+
+
+

docs/《PHP扩展开发》-协程-协程isExist.md

@@ -152,7 +152,7 @@ coroutine [2] is non-existent
 
 符合预期。
 
-
+[下一篇：修复一些bug（三）](./《PHP扩展开发》-协程-修复一些bug（三）.md)
 
 
 

study_coroutine_util.cc

@@ -69,6 +69,10 @@ PHP_METHOD(study_coroutine_util, resume)
 PHP_METHOD(study_coroutine_util, getCid)
 {
     Coroutine* co = Coroutine::get_current();
+    if (co == nullptr)
+    {
+        RETURN_LONG(-1);
+    }
     RETURN_LONG(co->get_cid());
 }
 

test.php

 <?php
 
-function task($arg)
-{
-	$cid = Study\Coroutine::getCid();
-	echo "coroutine [{$cid}] create" . PHP_EOL;
-	Study\Coroutine::yield();
-	echo "coroutine [{$cid}] is resumed" . PHP_EOL;
-}
+$cid = Study\Coroutine::getCid();
+echo "coroutine [{$cid}] create" . PHP_EOL;
 
-echo "main coroutine" . PHP_EOL;
-$cid1 = Study\Coroutine::create('task', 'a');
-echo "main coroutine" . PHP_EOL;
-$cid2 = Study\Coroutine::create('task', 'b');
-echo "main coroutine" . PHP_EOL;
+// function task($arg)
+// {
+// 	$cid = Study\Coroutine::getCid();
+// 	echo "coroutine [{$cid}] create" . PHP_EOL;
+// 	Study\Coroutine::yield();
+// 	echo "coroutine [{$cid}] is resumed" . PHP_EOL;
+// }
 
-if (Study\Coroutine::isExist($cid1))
-{
-	echo "coroutine [{$cid1}] is existent\n";
-}
-else
-{
-	echo "coroutine [{$cid1}] is non-existent\n";
-}
-
-if (Study\Coroutine::isExist($cid2))
-{
-	echo "coroutine [{$cid2}] is existent\n";
-}
-else
-{
-	echo "coroutine [{$cid2}] is non-existent\n";
-}
-
-Study\Coroutine::resume($cid1);
-echo "main coroutine" . PHP_EOL;
-if (Study\Coroutine::isExist($cid1))
-{
-	echo "coroutine [{$cid1}] is existent\n";
-}
-else
-{
-	echo "coroutine [{$cid1}] is non-existent\n";
-}
-
-if (Study\Coroutine::isExist($cid2))
-{
-	echo "coroutine [{$cid2}] is existent\n";
-}
-else
-{
-	echo "coroutine [{$cid2}] is non-existent\n";
-}
-Study\Coroutine::resume($cid2);
-echo "main coroutine" . PHP_EOL;
-if (Study\Coroutine::isExist($cid1))
-{
-	echo "coroutine [{$cid1}] is existent\n";
-}
-else
-{
-	echo "coroutine [{$cid1}] is non-existent\n";
-}
-
-if (Study\Coroutine::isExist($cid2))
-{
-	echo "coroutine [{$cid2}] is existent\n";
-}
-else
-{
-	echo "coroutine [{$cid2}] is non-existent\n";
-}
+// echo "main coroutine" . PHP_EOL;
+// $cid1 = Study\Coroutine::create('task', 'a');
+// echo "main coroutine" . PHP_EOL;
+// $cid2 = Study\Coroutine::create('task', 'b');
+// echo "main coroutine" . PHP_EOL;
+// Study\Coroutine::resume($cid1);
+// echo "main coroutine" . PHP_EOL;
+// Study\Coroutine::resume($cid2);
+// echo "main coroutine" . PHP_EOL;