Create system call is used to create the process. The parent process creates the child process by using the create system call which may create many other processes they use the tree format for process creation which is simply called as the inheritance in programing term. Process identifier (Pid) which is generally used to manage and identify the process. Resource sharing option. Commonly a process required resources like CPU time, memory, I/O devices and files to accomplish the task. A Parent process can have many child processes and child process can have further child processes.
- Parent and child processes share all resources
Whenever a parent process creates a child processes these sub processes can directly attain the required resources from the operating system also it may be constructed to a subset of the resources of the parent process.
- Subprocesses share the subset of parent’s resources
The parent process may have to partition its resources among its subprocesses, or it can be capable to share some of the parent’s resources such as files and memory among the various its child processes. In this case sub processes are allocated the subset of parent’s resources.
- Parent and child processes share no process
Bounding the sub process to a sub set of the parent’s resources avoid any process form overloading the system by creating too many child processes. It helps to prevent creation of too many subprocesses which can be a cause of confusion for operating system.
- Child and parent processes can execute concurrently.
- The parent process waits until some or all of its child processes have terminated.
- The parent continues to execute simultaneously with its child process.
There are two possible ways according to address space of the new process:
- The child process can be duplicate of the parent process for example it has the same data and program as the parent.
- The child process can have a new program loaded into it.