Introduction
The simplest definition of Process is executing instance of an application. The process contains at least one thread. The thread is a fundamental unit of the operating system. Windows is a multitasking operating system. Every process contains at least one thread. Windows NT family system and Windows 95/98 based system support preemptive multitasking. So, we can work freely for multiple threads and multiple processors.
Process Class
In Microsoft .NET framework all the namespaces derived from Object. The System.Diagnostics namespace provides the information about the process state, start the new process, etc. In this namespace allows to starts the new process, kill process, etc.
In process class allows to monitor local system process information or remote system process information. We also interact with the ProcessThread and ProcessModule classes. The ProcessStartup class provides the arguments passing and etc. ProcessStartInfo Constructor use to initializes the process information.
ProcessStartInfo contains the following properties.
Arguments
The arguments property use to set the argument in file name like ShellExecute function.
Filename
The FileName Property is used to set the application name . We can set this property before starting the process class.
UseShellExecute
If we set this is True we can perform the file operations (like, printing the contents in that file). If we set False we just execute the application.
WindowStyle
We set and get the WindowStyle in process starting time.
WaitForExit
WaitForExit property is to wait for the process fora specified time.
For Example :-
Notepad->waitForExit(1000) // waits 1000 seconds.
Kill
Kill property is to kill the currently running process.
Ex :- notePad->Kill();
The following code is to start the notepad. It waits 1000 secounds and kills it automatically using kill property in Process class.
Process *notePad = new Process();
notePad->StartInfo->FileName = "notepad.exe";
notePad->StartInfo->Arguments = "textfile.txt";
notePad->Start();
notepad->waitForExit(1000);
notepad->Kill();
Process Thread Class
The Process Thread contains information about the currently running process. We control the threads within the process. We set or get the thread proprieties like low, high. The Process Thread class contains the following properties.
BasePriority
The BasePrority is used to get the priority.
CurrentPriority
The CurrentPriority Class is to get the current priority
PriorityLevel
The PriorityLevel is to Get or set the priority level
ThreadState
The ThreadState is to get the current state
ProcessModule class
The ProcessModule class is to get the information about the process module. In ProcessModule class, properties are used to get the information like get module name, memory size in the module, etc.
The following code explains the use of ProcessModule class to get module name, fileinfo etc.
Process *notePad = new Process();
notePad->StartInfo->FileName = "notepad.exe";
notePad->StartInfo->Arguments = "selvam.txt";
notePad->Start();
System::Threading::Thread::Sleep(1000);
ProcessModule *myProcessModule;
myProcessModule = notePad->MainModule;
String *strFileName, *strModuleName;
int nMemory;
strFileName = myProcessModule->FileName;
strModuleName = myProcessModule->ModuleName;
nMemory = myProcessModule->ModuleMemorySize;
Conclusion
The .NET framework is used to simplify the programming model. So, we can easily interact with the operating system. The Process class is useful to start the new process, stop the existing process and control the process. ProcessModule class is used to get the module information in the running application.