cost for 200-301

cost for 200-301.As you can see from Figure 9.2, child processes can share certain resources with their associated parent processes, depending on how the operating system is implemented. Certain restrictions need to be placed on the child process to avoid consuming more resources than the parent process can provide, and should be considered best practice, as otherwise undesirable events will occur. The parent process can use the Wait system call, which puts the process in a suspended state until Wait returns. The parent process can also issue the Rim system call, which allows the child process to continue executing9.2 Processes 363The parent process can also issue a Rim system call to allow the child process to continue without waiting (essentially as a background task). A process can be terminated when one of the following conditions occurs in the system. The system has no resources to offer. The parent process is not required to complete the tasks assigned to the child process. The parent process stops running, indicating that the associated child process no longer has a parent, at which point the system will either terminate the child process.or it will be made to run as an orphan process.The Exit or Kill command is executed.When a process terminates, it not only releases all system resources associated with it, but also refreshes and closes all open files. If the parent process is waiting for the child process to terminate, the termination status and execution time will be returned to the parent process. If the process to be terminated is an orphan process, the same data will be returned to the init process.When the parent process terminates and the child process is allowed to continue running independently, an orphanprocess is created. The orphan process becomes a child of the init process, but is still marked as an orphan process because its parent process no longer exists. From the time the child process terminates until the system returns status information to the parent process, the system continues to "enter" the process as a record in the process table. In this case, the terminated process becomes a zombieprocess, and the associated memory and resources are freed, but it is still entered into the process table. Usually, the parent process receives a SIGCHILD signal to let it know that the child process has terminated. The parent process can then issue a Wait call to obtain the exit status of the terminated process, allowing the system to remove it from the process table. A zombie process can become a "nuisance" if the parent process is killed (kill) and is not allowed to be removed from the process table. A lingering zombie process will eventually be taken over by the init process and terminated.The following are important concepts related to processes.364 Chapter 9 Linux- and macOS-based AnalysisThere are two methods of starting processes, one in the foreground and one in the background.