Simple multithreading (utilizing OD to resolve run-time errors)

Code from the "VC + + in-depth" chapter 15th "Multithreading", located on page No. 563-page 566.

The purpose of the program is to demonstrate the effect of multi-threaded operation:

#include <windows.h>#include<iostream.h>DWORD WINAPI fun1proc (LPVOID lpparameter//Thread Data);intindex =0;intMain () {HANDLE hThread1; HThread1= CreateThread (NULL,0, Fun1proc,null,0, NULL);    CloseHandle (HTHREAD1);  while(Index++ < +) cout<<"main thread is running."<<Endl; return 0;} DWORD WINAPI Fun1proc (LPVOID lpparameter//Thread Data){     while(Index++ < +) cout<<"Thread1 is running"<<Endl; return 0;} 

The runtime found that the program crashed:

Click Cancel with OD debugging:

The program was discovered because the memory that read a 0 address throws an exception. F5 Debug Programs in VC6:

The yellow arrow points to the code that references the pointer p, and P has a value of 0, which throws an exception. Right-click the open file's properties to view the filename:

is a C language file, the file name is write, the meaning of writing. What operation of our program is used to write? That's right! Use the cout to output a string to the screen.

Change the # include statement to the standard format:

#include <windows.h>#include<iostream>using namespaceStd;dword WINAPI fun1proc (LPVOID lpparameter//Thread Data);intindex =0;intMain () {HANDLE hThread1; HThread1= CreateThread (NULL,0, Fun1proc,null,0, NULL);    CloseHandle (HTHREAD1);  while(Index++ < +) cout<<"main thread is running."<<Endl; return 0;} DWORD WINAPI Fun1proc (LPVOID lpparameter//Thread Data){     while(Index++ < +) cout<<"Thread1 is running"<<Endl; return 0;}

You can run it perfectly:

However, what is this for? We just guessed the address of the problem and didn't know the principle. Try Baidu for a moment:

iostream.h and iostream are different. #include <iostream.h> is used in the old standard C + +. In the new standard, use #include<iostream>. Iostream means the input and output stream. #include <iostream> is a standard C + + header file , and any standard C + + development environment has this header file. Also note: In VC programming to add: using namespace std; The reason for this is that the header file with the suffix. h C + + standard has been explicitly not supported, the earlier implementation of the standard library functions defined in the global space, declared in the header file with the. h suffix, C + + standard in order to distinguish with C, and in order to correctly use the namespace, the header file does not use the suffix. Therefore, when using <iostream.h>, the equivalent of calling library functions in C, using the global namespace, which is the earlier C + + implementation, when using <iostream>, the header file does not define a global namespace. Namespace STD must be used so that cout can be used correctly. Relationship <string.h> is the old C header file , corresponding to the char*-based string processing function;<string> is the C + + header file that wraps the STD, corresponding to the new string class;< Cstring> is the STD version that corresponds to the old C header file. The relationship between <iostream.h> and <iostream>, similar to the <string.h> and <cstring> relationships, implements the same functionality, primarily whether the distinction between using a namespace STD is used.

The reason is that we use. h header files that are not supported by the C + + standard, where the processing functions are written in the C language, so that the char*-based processing functions are likely to have large problems in multi-threading, or <iostream> are more secure and more compliant.

Simple multithreading (utilizing OD to resolve run-time errors)