Returns the parent handle of the supplied process.
proc_parent() function is used to retrieve the parent handle of a given process. It takes a process identifier (PID) as input and returns the PID of the parent process.
In POSIX systems, each process has a parent process except for the initial process, which is typically assigned a parent of PID 1 (init process). The parent process is responsible for creating and managing its child processes.
;;; Returns the parent handle of a particular process (@interface func (export "proc_parent") ;;; Handle of the process to get the parent handle for (param $pid $pid) (result $error (expected $pid (error $errno))) )
ctx: The function environment.
pid: The process identifier (PID) of the process whose parent is to be retrieved.
ret_parent: Pointer to store the returned parent process ID.
The function returns an
Errno value indicating the result of the operation. If the operation is successful, it returns
Errno::Success. If the supplied process does not exist or the current process is not the parent, it returns
This function is instrumented with
debug level logging. It includes the following field for debugging purposes:
pid: The process identifier (PID) of the supplied process.
parent: The parent process ID.
proc_parent()function is used to retrieve the parent handle of a given process.
- It checks if the supplied
pidmatches the current process's PID. If they match, it retrieves the parent PID using the
ppid()method of the current process.
- If the supplied
piddoes not match the current process's PID, it attempts to retrieve the process from the control plane using the
- The function stores the parent PID in the specified
- The function returns
Errno::Badfif the supplied process does not exist or the current process is not the parent.