If I define a variable inside the block of a control structure, does it exist only in the execution of that control structure's block and not in the whole execution of the enclosing function? also how can I monitor the exact memory usage of my programs and its changes (ie: changes in memory usage by creating and destroying variables)? added later: in following code I know v scope is if bl
如果我在控制结构的块中定义一个变量，它是否仅存在于该控制结构块的执行中，而不存在于封闭函数的整个执行中？ 我该如何监视程序及其更改的确切内存使用情况（即：通过创建和销毁变量来改变内存使用情况）？ 稍后添加：在下面的代码中，我知道v范围是if块，但我想知道v是在if块的开始/结束处还是在函数func的开始/结束处在内存中创建/销毁？ void func () { if (true) { int v;//automatic storage class
Possible Duplicate: Any reason to overload global new and delete? Why should we overload/override new and delete in C++? Give me an example of situation in which we should overload/override new, new[], delete or delete[]. This sounds a bit like a homework assignment. Nevertheless, here are two uses off the top of my head: For profiling purposes. For instance, we use it in a library as
可能重复： 有什么理由重载全局新建和删除？ 为什么我们应该在C ++中重载/重写new和delete？ 给我一个例子，我们应该重载/重写new，new []，delete或delete []。 这听起来有点像家庭作业。 尽管如此，我还有两个用途： 为了剖析目的。 例如，我们把它作为一个穷人的valgrind在图书馆中用来追踪内存泄漏。 为您的对象实现自定义分配器（例如池分配器）。 通常我会为此实现一个allocator 。 提供分配/取消分配内
The dynamic memory allocation operators - new and delete can be overridden for a specific class. I could define a different memory allocation scheme than the default that is provided by the C++ Run-time on windows. I have few questions related to it: Is overriding new and delete operator for a specific class portable such that it also works on unix? Is it part of the C++ standard? What are
动态内存分配操作符 - new和delete可以为特定的类重写。 我可以定义一个不同于Windows上C ++运行时提供的默认内存分配方案。 我有几个相关的问题： 是重写新的和删除运算符的特定类可移植，这样它也可以在UNIX上工作？ 它是C ++标准的一部分吗？ 什么情况下可能需要重写特定类的内存分配操作符？ 只有我能想到的情况是 - 跟踪内存泄漏分配。 是的，它是可移植的，但要注意MS编译器处理与ANSI标准不同的'nothrow&#
How can I automatically detect memory leaks in C++ in a portable way? I am looking for some sort of templating solution where I can just use a macro like NEW or DELETE to track creation and deletion. It has to work on Mac, Linux, and Windows. There are a lot of tools available for that. Eg special libraries like dmalloc libraries like libfence. On Linux especially Valgrind is very useful.
我如何以便携方式自动检测C ++中的内存泄漏？ 我正在寻找某种模板解决方案，我可以使用像NEW或DELETE这样的宏来跟踪创建和删除。 它必须在Mac，Linux和Windows上工作。 有很多可用的工具。 例如像libfence这样的特殊库，如dmalloc库。 特别是在Linux上，Valgrind非常有用。 所以最好的“赌注”可能是你获得一些malloc调试库源代码并将其用于你的所有开发中。 我建议在Linux和Mac OSX上运行valgrind，在Windows上运行Micr
Hello So I'm experimenting with creating objects and arrays with preallocated memory. For instance I have this following code: int * prealloc = (int*)malloc(sizeof(Test)); Test *arr = new(prealloc) Test(); Where test is defined as follows: class Test { public: Test() { printf("In Constructorn"); } ~Test() { printf("In Destructorn"); } int val; }; In
你好所以我正在试验用预先分配的内存创建对象和数组。 例如，我有以下代码： int * prealloc = (int*)malloc(sizeof(Test)); Test *arr = new(prealloc) Test(); 测试定义如下： class Test { public: Test() { printf("In Constructorn"); } ~Test() { printf("In Destructorn"); } int val; }; 在这种情况下，如果我调用删除它实际上会释放内存不好，B / C也许我正在使用某种类型
Is it possible to overload class specific new/delete that is called when arrays of objects are created. class Foo; Foo* f = new Foo[10]; // calls overloaded new delete[] f; // calls overloaded delete Thank you. Yes, it is possible. There is a tutorial about overloading new and delete here, and there is a nice example of overloading new and delete for array, here. class Myclass { public:
是否有可能重载在创建对象数组时所调用的特定于类的新/删除。 class Foo; Foo* f = new Foo[10]; // calls overloaded new delete[] f; // calls overloaded delete 谢谢。 对的，这是可能的。 在这里有一个关于重载new和delete的教程，这里有一个很好的例子，它重载了new和delete的数组。 class Myclass { public: void* operator new(size_t); void operator delete(void*); void* operator
I was just answering a question about the lack of placement delete corresponding to placement new. The reason seems to be the way operator delete is called according to the dynamic type of the object (corresponding to the type used to find operator new ). Placement new has been useful to me. When it comes to custom allocation, there is probably a reusable class where different instances manag
我刚刚回答了关于缺少与展示位置相关的展示位置删除的问题。 原因似乎是根据对象的动态类型（与用于查找operator new的类型相对应）调用operator delete的方式。 安置new对我有用。 当涉及到自定义分配时，可能有一个可重用的类，其中不同的实例管理不同的池。 单身是一种反模式，所有这一切。 我能理解制造new thing;的便利性new thing; 在不跟踪分配器的情况下工作，但为类型层次结构的不同分支做事似乎相当复杂。
Using special compiler commands a symbol can be declared weak. According to Wikipedia: a weak symbol is a symbol definition in an object file or dynamic library that may be overridden by other symbol definitions In what scenarios or for what applications do you need weak symbols? What are typical use cases? One use of weak linking is implementing the replaceable functions in the C++ stand
使用特殊的编译器命令可以将符号声明为弱。 根据维基百科： 弱符号是目标文件或动态库中的符号定义，可能会被其他符号定义覆盖 在什么情况下或为什么应用程序需要弱符号？ 典型的用例是什么？ 弱链接的一种用法是在C ++标准中实现可替换的功能。 即： void *operator new(std::size_t); void *operator new(std::size_t, std::nothrow_t const &) noexcept; void *operator new[](std::size_t); void *operator new
Unless you're programming parts of an OS or an embedded system are there any reasons to do so? I can imagine that for some particular classes that are created and destroyed frequently overloading memory management functions or introducing a pool of objects might lower the overhead, but doing these things globally? Addition I've just found a bug in an overloaded delete function - memo
除非您正在编程操作系统或嵌入式系统的某些部分，否则有任何理由这样做？ 我可以想象，对于一些经常被创建和销毁的特定类而言，重载内存管理函数或者引入一个对象池可能会降低开销，但是在全局上做这些事情呢？ 加成 我刚刚发现一个重载删除函数的错误 - 内存并不总是被释放。 这是一个不太重要的内存关键应用程序。 而且，禁用这些过载只会使性能下降约0.5％。 我们因为多种原因而在全球范围内重载新的和删除操作符：
It is not easy to write a iocp console server，socket pool and thread pool works well，but after some times leater, the server can not connect agagin, nothing wrong happen, why? i use procexp_16.05.1446001339.exe to check the process properties, i found lots of close_wait status, after some times agagin, close_wait status disappear, but the server still can not connect? why? and how to fix it
编写一个iocp控制台服务器并不容易，套接字池和线程池运行良好，但经过一段时间后，服务器无法连接agagin，没有发生任何错误，为什么？ 我使用procexp_16.05.1446001339.exe来检查进程属性，我发现很多close_wait状态，经过一段时间agagin，close_wait状态消失，但服务器仍然无法连接？ 为什么？ 以及如何解决它？ #include "stdafx.h" #include "Winsock2.h" #include "Windows.h" #include "Winbase.h"