What is session leader process?
A session leader is a process where session id == process id. This sounds contrived, but the session id is inherited by child processes. Some operations within UNIX/Linux operate on process sessions, for example, negating the process id when sending to the kill system call or command.
What is session life cycle?
In providing access management services, Sun ™ ONE Identity Server allows for the creation of session objects which are used to track user interaction with web applications across multiple HyperText Transfer Protocol (HTTP) requests.
When do processes belong to the same session?
In other words, all the processes in a process group must belong to the same session. setpgid () call places the calling process into its own process group and its own session. This is necessary to ensure that two sessions do not contain processes in the same process group.
How are processes added to a process group?
Processes are added to a process group through setpgid (). pid is the process that is being placed in a new process group (0 may be used to indicate the current process). pgid is the process group ID the process pid should belong to, or 0 if the process should be in a new process group whose pgid is the same as that process’s pid.
Is the process ID equal to the process group ID?
In general, yes, the process group ID is equal to the process ID of the process that created the process group — and that process created the process group by putting itself in the group. You can find this information in the documentation of the setpgid system call, and of its variant setpgrp.
Can a session leader change its process group?
A session leader may not change its process group. A process may not be moved into a process group whose leader is in a different session from itself. In other words, all the processes in a process group must belong to the same session. setpgid () call places the calling process into its own process group and its own session.