id=8077 从MySQL 5.7.6版本开始,如果启用了NO_BACKSLASH_ESCAPES, 则mysql_real_escape_string()函数失败,错误码为CR_INSECURE_API_ERR...启用NO_BACKSLASH_ESCAPES,表示将反斜杠当作普通字符,而不是转义字符: SET sql_mode='NO_BACKSLASH_ESCAPES'; 查看当前的SQL模式:...************ 1. row *************************** \: \ 1 row in set (0.00 sec) 在启用NO_BACKSLASH_ESCAPES...后(反斜杠为普通字符): mysql> SET sql_mode='NO_BACKSLASH_ESCAPES'; Query OK, 0 rows affected (0.00 sec)...("%s", "SET sql_mode='NO_BACKSLASH_ESCAPES'"); printf("%s\n", mysql.escape_string(argv[2]).c_str
/memory_analysis.go:29:17: len1 escapes to heap..../memory_analysis.go:37:17: len2 escapes to heap..../memory_analysis.go:45:17: len3 escapes to heap..../memory_analysis.go:53:17: len4 escapes to heap..../memory_analysis.go:79:17: len7 escapes to heap
/memory_analysis.go:8:12: &student{...} escapes to heap&student{...} escapes to heap表示对象已经逃逸到堆上。.../memory_analysis.go:26:19: make([]int, length) escapes to heapmake([]int, length) escapes to heap表示已经逃逸到堆上了.../memory_analysis.go:69:17: val escapes to heap"Hello world." escapes to heap和val escapes to heap表示这两个变量都已经发生了逃逸.../memory_analysis.go:56:12: func literal escapes to heap....." + name escapes to heapfunc literal escapes to heap表示函数已经发生了逃逸。
/main.go:10:11: make([]int64, 8192) escapes to heap ./main.go:11:13: ... argument does not escape ..../main.go:11:17: len(a) escapes to heap 其实原因也很简单,这里的 a slice 太大了,栈放不下了,所以只能放到堆上了 案例说明 案例来源:https://github.com...的单元测试肯定包含了大多数出现逃逸情况,情况数量极多,下面举例其中一些 将内部变量作为指针返回 显然当你作为指针返回后,外部就可能会使用和修改,就必须在堆上,不能随着函数返回就不见了 func i_escapes...to heap" s2 := make([]int, 0, n) // ERROR "make\(\[\]int, 0, n\) escapes to heap" } 这里的 s1 也是会分配到堆上的...sink = y // ERROR "y escapes to heap" } atomic 操作 当然将一些内部变量通过 atomic 操作放到全局变量上,肯定也会逃逸的
/true.go:10:10: new(struct {}) escapes to heap ./true.go:11:10: new(struct {}) escapes to heap ..../true.go:12:13: c escapes to heap ./true.go:12:13: d escapes to heap ..../true.go:12:22: c == d escapes to heap ..../true.go:12:13: io.Writer(os.Stdout) escapes to heap :1: (*File).close .this does not
/main.go:8:10: new(A) escapes to heap ./main.go:16:13: io.Writer(os.Stdout) escapes to heap ..../main.go:16:13: c escapes to heap ./main.go:15:9: b + "!" escapes to heap ..../main.go:8:10: new(A) escapes to heap 说明 new(A) 逃逸了,符合上述提到的常见情况中的第一种。 ....escapes to heap 说明 c 变量逃逸,通过fmt.Println(a ...interface{})打印的变量,都会发生逃逸,感兴趣的朋友可以去查查为什么。 以上操作其实就叫逃逸分析。
/main.go:6:18: make([]struct {}, iter.n) escapes to heap: ..../main.go:6:18: make([]struct {}, iter.n) escapes to heap 按照前面的分析,从 “make([]struct {}, iter.n) escapes...逃逸分析识别出 escapes to heap,并不一定就是堆分配,也可能是栈分配。 进行内存分配器追踪时,如果采集不到堆分配信息,那一定只有栈分配。...如果该变量被识别为 escapes to heap,那么它十有八九是被分配在堆上。 如果该变量被识别为 does not escape,或者没有与之相关的分析结果,那么它一定是被分配在栈上。...如果对 escapes to heap 心存疑惑,就对代码作内存分配器追踪。 如果有采集到与该变量相关的分配信息,那么它一定是被分配在堆上。 否则,该变量一定是被分配在栈上。
/scratch.go:4:14: "Called stackAnalysis" escapes to heap ..../scratch.go:4:51: stackAnalysis() escapes to heap ....❝"escapes to heap"的意思是变量需要在函数栈之间共享,上面的例子就是在main和fmt.Println之间共享。 ❞ ?.../scratch.go:4:14: "Called heapAnalysis" escapes to heap ..../scratch.go:4:49: heapAnalysis() escapes to heap .
/test2.go:9:13: from ... argument (passed to call[argument content escapes]) at ..../test3.go:9:9: func literal escapes to heap ..../test3.go:10:3: &n escapes to heap ..../test4.go:16:14: make([]int, 1000000) escapes to heap ..../test4.go:25:11: make([]int, number) escapes to heap .
/main.go:8:7: &demo literal escapes to heap: ..../main.go:8:7: &demo literal escapes to heap $ go tool compile -l -m -m main.go main.go:8:7: &demo literal...escapes to heap: main.go:8:7: flow: d = &{storage for &demo literal}: main.go:8:7: from &demo...to heap main.go:15:13: ... argument does not escape main.go:15:16: in() escapes to heap main.go:16:13...: ... argument does not escape main.go:16:16: in() escapes to heap 函数使用值与指针返回时性能的差异 上文介绍了 Go 中变量内存分配方式
\main.go:9:10: new(Person) escapes to heap ....\main.go:18:16: new(Person) does not escape 代码第9行显示”escapes to heap”,表示该行内存分配发生了逃逸现象。...\main.go:4:11: make([]int, 10000, 10000) escapes to heap 发现当切片长度扩大到10000时就会逃逸。...\main.go:6:13: s escapes to heap ....\main.go:11:9: func literal escapes to heap 总结 栈上分配内存比在堆中分配内存效率更高 栈上分配的内存不需要 GC 处理,而堆需要 逃逸分析目的是决定内分配地址是栈还是堆
| 38 kB 00:00 (4/9): perl-Pod-Escapes...Running Transaction Test Transaction Test Succeeded Running Transaction Installing : 1:perl-Pod-Escapes... 8/9 Verifying : 1:perl-Pod-Escapes...12.el6 perl.x86_64 4:5.10.1-127.el6 perl-Module-Pluggable.x86_64 1:3.90-127.el6 perl-Pod-Escapes.x86
上述这段话的大概意思就是说,MySQL在默认情况下(SQL模式不是“NO_BACKSLASH_ESCAPES”)会将插入字段中的字符“”删除掉。 解决方案 既然找到的问题的根源,那就不难解决了。...实际上,有2种解决办法: 方法一 修改MySQL配置,让MySQL的SQL模式运行在“NO_BACKSLASH_ESCAPES”模式下。 ?...默认情况下,MySQL的SQL模式不包含“NO_BACKSLASH_ESCAPES”。修改配置文件“/etc/my.cnf”,重启MySQL即可。...修改MySQL的SQL模式为“NO_BACKSLASH_ESCAPES”之后,再次插入带有字符“”的内容就不再会被删除了。...NUL时,会在这些字符前面再加一个转义字符\,所以最终发送给MySQL服务器的SQL语句中这些字符对应就变成了\',\",\\,\NUL,如果此时MySQL的SQL模式不是”NO_BACKSLASH_ESCAPES
./01.go:9:11: "tom" escapes to heap interface{} 赋值,会发生逃逸,优化方案是将类型设置为固定类型,例如:string package main type...GetStudent() } 分析结果: go run -gcflags '-m -l' 02.go # command-line-arguments ./02.go:8:12: new(Student) escapes...分析结果: go run -gcflags '-m -l' 03.go # command-line-arguments ./03.go:4:14: make([]int, 10000, 10000) escapes
/c.go:20:24: *p escapes to heap ..../escape.go:10:12: func literal escapes to heap 返回指针 package main type User struct { name string.../escape.go:3:11: make([]int64, 8192, 8192) escapes to heap: ..../escape.go:5:11: make([]int32, n) escapes to heap: ..../escape.go:5:11: make([]int32, n) escapes to heap 编译器给出解释为non-constant size。
Sharing up typically escapes to the heap 在被调用函数内创建的对象,以指针的形式返回给调用方的情况下,通常,创建的内存空间在堆上。.../main.go:28:9: &Obj literal escapes to heap} func initFn() func() { return func() { // ..../main.go:32:9: func literal escapes to heap println("I am a function") }} func add(i int) int {.../main.go:24:9: &Obj literal escapes to heap....这里给读者留个问题,大家可以研究下 moved to heap 和 escapes to heap 的区别。
Sharing up typically escapes to the heap 在被调用函数内创建的对象,以指针的形式返回给调用方的情况下,通常,创建的内存空间在堆上。.../main.go:28:9: &Obj literal escapes to heap} func initFn() func() { return func() { // ..../main.go:32:9: func literal escapes to heap println("I am a function") }} func add(i int) int {.../main.go:24:9: &Obj literal escapes to heap....这里给读者留个问题,大家可以研究下 moved to heap 和 escapes to heap 的区别。 总结 1.因为栈比堆更高效,不需要 GC,因此 Go 会尽可能的将内存分配到栈上。
_escapes = /\\([!"#$%&'()*+,\-./:;?@\[\]\\^_`{|}~])/g; 改成 inline._escapes = /\\([!"
timings.Start("fe", "escapes") escapes(xtop) ... ... } 下面是escapes函数的实现: // $GOROOT/src/cmd/compile.../printf1.go:8:13: a escapes to heap 我们看到逃逸分析输出第8行的变量“a escapes to heap”,不过这个“逃逸”有些奇怪,因为按照之前的经验,如果某个变量真实逃逸了.../printf1.go:8:13: a escapes to heap”这句的含义究竟是什么呢?.../printf1.go:8:13: a escapes to heap”是否指的是装箱后的值部分在堆上分配呢?这里也不确定。.../printf2.go:8:40: &a escapes to heap ./printf2.go:8:40: &a escapes to heap .
/main.go:7: x escapes to heap 4..../foo1.go:10:16: ([]byte)(in) escapes to heap 3..../foo1.go:9:17: hash.Hash64(&fnv.s·2) escapes to heap 4./foo1.go:9:17: &fnv.s·2 escapes to heap 5..../foo1.go:17:13: s escapes to heap 8./foo1.go:17:59: hashIt(s) escapes to heap 9..../foo3.go:24:16: &s escapes to heap 2.
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