add qrcode

Author: cch123

Diff for: assembly.md

@@ -999,11 +999,5 @@ go compile -S:
 参考资料[4]需要特别注意，在该 slide 中给出的 callee stack frame 中把 caller 的 return address 也包含进去了，个人认为不是很合适。
 
 
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">
 
-
-<!--stackedit_data:
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-NjIzLDIwODQwNjM3MjAsLTE1NTYyODU0NDAsMTI2MTcwMTYyMy
-w3NTI0MDk2NTUsMTg4NDQ5NTE5MF19
--->

Diff for: atomic.md

@@ -359,4 +359,6 @@ TEXT runtime∕internal∕atomic·Store(SB), NOSPLIT, $0-12
 	MOVL	val+8(FP), AX
 	XCHGL	AX, 0(BX) // 交换指令
 	RET
-```
+```
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: bootstrap.md

@@ -518,4 +518,6 @@ func main() {
 <!--stackedit_data:
 eyJoaXN0b3J5IjpbOTA1MjAxMjAyLC0xNDUzNjA2MjEwLDkwNT
 IwMTIwMiwtMTQ1MzYwNjIxMCwtNTk2NzUzMDMxXX0=
--->
+-->
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: channel.md

@@ -705,3 +705,6 @@ func closechan(c *hchan) {
 Q: 如果有多个channel同时唤醒同一个goroutine，这个并发控制是怎么做的？
 
 Q: 为什么向 channel 发数据的时候，会直接把数据从一个 goroutine 的栈拷贝到另一个 goroutine 的栈？
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: context.md

@@ -566,3 +566,5 @@ func main() {
 # 总结
 
 ctx 的结构显然是根据代码的执行模型来设计的，虽然设计得比较巧妙，但因为将取消和上下文携带功能混合在一起，在一些情况下还是会给我们埋些比较隐蔽的坑。使用时需要多多注意。
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: defer.md

@@ -160,3 +160,6 @@ A: deferproc 和 deferreturn 是成对出现的，对于编译器的实现来说
 
 https://ieevee.com/tech/2017/11/23/go-panic.html
 
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: futex.md

@@ -235,3 +235,6 @@ http://blog.sina.com.cn/s/blog_e59371cc0102v29b.html
 https://www.jianshu.com/p/570a61f08e27
 
 https://eli.thegreenplace.net/2018/basics-of-futexes/
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: gc.md

@@ -742,3 +742,5 @@ gc时间，stw时间和响应延迟之间是什么关系
 
 宏观来看gc划分为多少个阶段
 
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: gc_write_barrier.md

@@ -2,3 +2,4 @@
 
 TODO
 
+

Diff for: generics.md

@@ -40,3 +40,5 @@ cat source.go | genny gen "Something=string"
 
 没有官方的泛型支持，社区怎么搞都是邪道。2021 年 1 月，官方的方案已经基本上成型，并释出了 [draft design](https://go.googlesource.com/proposal/+/refs/heads/master/design/go2draft-type-parameters.md)。
 
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: goroutine.md

@@ -7,4 +7,6 @@
 > Written with [StackEdit](https://stackedit.io/).
 <!--stackedit_data:
 eyJoaXN0b3J5IjpbNjQ5NDIwMDBdfQ==
--->
+-->
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: interface.md

@@ -543,3 +543,5 @@ go.itab.*os.File,io.Writer SRODATA dupok size=32
 
 // 下面就是正常流程了
 ```
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: io.md

@@ -722,3 +722,5 @@ func Splice(dst, src *FD, remain int64) (written int64, handled bool, sc string,
 
 - https://go-review.googlesource.com/c/go/+/271537/
 - https://zhuanlan.zhihu.com/p/308054212
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: lockfree.md

@@ -1,4 +1,6 @@
 # lock free programming in Go
 
 # 参考资料
-https://docs.google.com/presentation/d/1wuNNW-g6v8qizIc_IxAGZTj-49TODKF0TYddTA1VDUo/mobilepresent?slide=id.p
+https://docs.google.com/presentation/d/1wuNNW-g6v8qizIc_IxAGZTj-49TODKF0TYddTA1VDUo/mobilepresent?slide=id.p
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: map.md

@@ -1267,3 +1267,5 @@ func (h *hmap) incrnoverflow() {
     }
 }
 ```
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: memory.md

@@ -1396,3 +1396,6 @@ func (p *notInHeap) add(bytes uintptr) *notInHeap {
 ### 堆外内存用法
 
 嗯，堆外内存只是 runtime 自己玩的东西，用户态是使用不了的，属于 runtime 专用的 directive。
+
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: memory_barrier.md

@@ -569,3 +569,5 @@ https://stackoverflow.com/questions/29880015/lock-prefix-vs-mesi-protocol
 https://github.com/torvalds/linux/blob/master/Documentation/memory-barriers.txt
 
 http://www.overbyte.com.au/misc/Lesson3/CacheFun.html
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: netpoll.md

@@ -1355,3 +1355,5 @@ func poll_runtime_pollUnblock(pd *pollDesc) {
     }
 }
 ```
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: panic.md

@@ -295,4 +295,6 @@ func main() {
 	defer panic(2)
 	panic(1)
 }
-```
+```
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: pprof.md

@@ -771,5 +771,8 @@ runtime 自带的 pprof 已经在数据采集的准确性, 覆盖率, 压力等
 #开源项目 pprof 参考
 [nsq](https://github.com/nsqio/nsq/blob/v1.2.0/nsqd/http.go#L78-L88)
 [etcd](https://github.com/etcd-io/etcd/blob/release-3.4/pkg/debugutil/pprof.go#L23) 采用的是[配置式](https://github.com/etcd-io/etcd/blob/release-3.4/etcd.conf.yml.sample#L76)选择是否开启
+
 # 参考资料
-https://go-review.googlesource.com/c/go/+/299671
+https://go-review.googlesource.com/c/go/+/299671
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: scheduler.md

@@ -2348,3 +2348,4 @@ gcMarkDone --> forEachP
 
 当然，这里 entersyscall 和 entersyscallblock 比较特殊，虽然这俩函数的实现中有设置抢占标记，但实际上这两段逻辑是不会被走到的。因为 syscall 执行时是在 m 的 g0 栈上，如果在执行时被抢占，那么会直接 throw，而无法恢复。
 
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: select.md

@@ -826,3 +826,5 @@ sclose:
 Q: 如果select多个channel，有一个channel触发了，其他channel的waitlist需要不要主动去除？还是一直在那等着？
 
 A: waitlist 的出列是由 `func (q *waitq) dequeue() *sudog` 函数控制的，每个 sudog 携带了一个 `selectDone` 标志位，通过 `cas` 操作在每次 `dequeue` 的时候「惰性」去除队列中无效的元素
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Diff for: semaphore.md

@@ -735,4 +735,6 @@ func notifyListCheck(sz uintptr) {
 func sync_nanotime() int64 {
     return nanotime()
 }
-```
+```
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: signal.md

@@ -338,3 +338,5 @@ func main() {
     sh.Data = (uintptr)(unsafe.Pointer(&b[1]))
     sh.Len = bh.Len - 1
 ```
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: slice.md

@@ -1027,3 +1027,5 @@ Q: 既然被选中了唤醒的那个G，说明这个G就是一定要退出lock
 
 A:
 
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Diff for: sync.md

@@ -768,4 +768,6 @@ func entersyscall_gcwait() {
 
 3. https://mzh.io/golang-arm64-vdso
 
-4. https://blog.csdn.net/luozhaotian/article/details/79609077
+4. https://blog.csdn.net/luozhaotian/article/details/79609077
+
+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">

Diff for: syscall.md

@@ -779,3 +779,5 @@ func (t *Timer) Reset(d Duration) bool {
 ## 最后
 
 本篇内容主要是讲 Go 的定时器实现，工业界的定时器实现并不只有一种。如果你还想知道其它系统，比如 nginx 里是怎么实现定时器的，可以参考[这一篇](https://www.jianshu.com/p/427dfe8ad3c0)。
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+<img width="330px"  src="https://xargin.com/content/images/2021/05/wechat.png">