核心编程边读边小结4

作业一章也是API比较多，先把本章开始的一个例子重写一下，再说明一下书中介绍的API。

#include "stdafx.h"#include <iostream>#include <string>#include <windows.h>using namespace std;int _tmain(int argc, _TCHAR* argv[]){//询问一下当前进程是否已在作业中BOOL bInJob;IsProcessInJob(GetCurrentProcess(), NULL, &bInJob);if(bInJob){wcout << TEXT("currecnt process is already in Job!") << endl;return 0;}//为作业设一些安全限制，可设置的条件相当之多和复杂JOBOBJECT_BASIC_LIMIT_INFORMATION jbli = {0};jbli.PriorityClass = IDLE_PRIORITY_CLASS;jbli.PerJobUserTimeLimit.QuadPart = 1000;JOBOBJECT_BASIC_UI_RESTRICTIONS jbur;jbur.UIRestrictionsClass = JOB_OBJECT_UILIMIT_NONE|JOB_OBJECT_UILIMIT_EXITWINDOWS | JOB_OBJECT_UILIMIT_HANDLES;//创建一个作业HANDLE hJob = CreateJobObject(NULL, TEXT("SomeJob"));//把安全限制和作业关联起来SetInformationJobObject(hJob, JobObjectBasicLimitInformation, &jbli, sizeof(jbli));SetInformationJobObject(hJob, JobObjectBasicUIRestrictions, &jbur, sizeof(jbur));//创建进程，并把之加入作业中STARTUPINFO si = {sizeof(si)};PROCESS_INFORMATION pi;TCHAR cmd[] = TEXT("NOTEPAD");if( CreateProcess(NULL, cmd, NULL, NULL, FALSE, CREATE_SUSPENDED | CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi) ){AssignProcessToJobObject(hJob, pi.hProcess);ResumeThread(pi.hThread);CloseHandle(pi.hThread);//等待作业或进程结束，再进行统计HANDLE hdls[] = { pi.hProcess, hJob };DWORD dwCondition = WaitForMultipleObjects(sizeof(hdls) / sizeof(HANDLE), hdls, FALSE, INFINITE);switch(dwCondition - WAIT_OBJECT_0){case 0: //do something herebreak;case 1://do something herebreak;}FILETIME CreationTime, ExitTime, KernelTime, UserTime;GetProcessTimes(pi.hProcess, &CreationTime, &ExitTime, &KernelTime, &UserTime);wcout << TEXT("Kernel = ") << KernelTime.dwLowDateTime / 1000 << " and User = "<< UserTime.dwLowDateTime / 10000 << endl;CloseHandle(pi.hProcess);}CloseHandle(hJob);system("PAUSE");return 0;}

另外的API内容有：

1.         对作业中的进程进行限制。用SetInformationJobObject函数，参数复杂，详细的就见书或MSDN吧。

2.         终止作业，TerminateJobObject函数。

3.         查询统计信息，QueryInformationJobObject。

4.         和完成端口结合进行使用。