proc_signal()
Sends a signal to a child process.
Description
The proc_signal()
function is used to send a signal to a specific child process identified by its PID. The signal specified by the sig
parameter is sent to the child process, which allows for various forms of inter-process communication and process control.
On POSIX systems, a similar functionality is provided by the kill()
function. It allows sending a signal to a process or a group of processes identified by their process ID. The kill()
function is part of the POSIX standard and is widely supported across different platforms.
Syntax
;;; Sends a signal to another process
(@interface func (export "proc_signal")
;;; ID of the process to send a singal
(param $pid $pid)
;;; Signal to send to the thread
(param $signal $signal)
(result $error (expected (error $errno)))
)
Parameters
ctx
: A mutable reference to the function environment.pid
: The PID of the child process to which the signal will be sent.sig
: The signal to send to the child process.
Return Value
The function returns a Result
indicating the success or failure of the operation. If the operation is successful, it returns Ok(Errno::Success)
. Otherwise, it returns an appropriate WasiError
value.
Logging
This function is instrumented with trace
level logging. It includes the following fields for debugging purposes:
pid
: The PID of the child process.sig
: The signal being sent.
Notes
- The
proc_signal()
function sends a signal to the child process identified by its PID. - If a process with the specified PID is found, the signal specified by the
sig
parameter is sent to that process. - On POSIX systems, a similar functionality is provided by the
kill()
function, which allows sending signals to processes identified by their process ID. - Sending signals to processes enables inter-process communication and process control. Signals can be used for various purposes, such as terminating a process, handling specific events, or requesting actions from the receiving process.