Golang中panic与recover的区别

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我是靠谱客的博主兴奋心锁，这篇文章主要介绍Golang中panic与recover的区别，现在分享给大家，希望可以做个参考。

前言

与defer类似的是，goroutine 中也有一个_panic链表头指针指向一个_panic链，发生panic的时候也是在链表头插入_panic结构体（执行gopanic）

在执行过程中发生了panic。那么panic以后的代码不会执行，转而执行panic的逻辑，再执行defer，执行到的defer要将started标记为true，同时将其defer结构体中的_panic指针指向当前的_panic，表示这个defer是由该panic触发的。再去执行defer链表，如果defer执行中还触发了panic，panic后的代码不载执行，将这个panic插入panic链头，同时将其作为当前panic。当遇到了与当前panic不符的defer，就找到该defer上的panic，将其标记为已终止，从defer链表中移除当前执行的defer。打印panic移除信息，从链表尾开始逐步输出

流程

panic执行defer的流程：

先标记started=true，_panic=&panic
后释放
目的是为了终止之前发生的panic

异常信息的输出方式：

所有还在panic链表上的项会被输出
顺序与发生panic的顺序一致

复制代码

// A _panic holds information about an active panic.
//
// A _panic value must only ever live on the stack.
//
// The argp and link fields are stack pointers, but don't need special
// handling during stack growth: because they are pointer-typed and
// _panic values only live on the stack, regular stack pointer
// adjustment takes care of them.
type _panic struct {
    // argp 存储当前要执行的defer的函数参数地址
	argp      unsafe.Pointer // pointer to arguments of deferred call run during panic; cannot move - known to liblink
	// arg panic函数自己的参数
    arg       interface{}    // argument to panic
    // link，链到之前发生的panic
	link      *_panic        // link to earlier panic
	pc        uintptr        // where to return to in runtime if this panic is bypassed
	sp        unsafe.Pointer // where to return to in runtime if this panic is bypassed
	// recovered 标识panic是否被恢复
    recovered bool           // whether this panic is over
    // aborted 标识panic是否被终止
	aborted   bool           // the panic was aborted
	goexit    bool
}

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// A _panic holds information about an active panic.
//
// A _panic value must only ever live on the stack.
//
// The argp and link fields are stack pointers, but don't need special
// handling during stack growth: because they are pointer-typed and
// _panic values only live on the stack, regular stack pointer
// adjustment takes care of them.
type _panic struct {
    // argp 存储当前要执行的defer的函数参数地址
	argp      unsafe.Pointer // pointer to arguments of deferred call run during panic; cannot move - known to liblink
	// arg panic函数自己的参数
    arg       interface{}    // argument to panic
    // link，链到之前发生的panic
	link      *_panic        // link to earlier panic
	pc        uintptr        // where to return to in runtime if this panic is bypassed
	sp        unsafe.Pointer // where to return to in runtime if this panic is bypassed
	// recovered 标识panic是否被恢复
    recovered bool           // whether this panic is over
    // aborted 标识panic是否被终止
	aborted   bool           // the panic was aborted
	goexit    bool
}