psignal, pgsignal, gsignal - post signal to a process
psignal(struct proc *p, int signum);
pgsignal(struct pgrp *pgrp, int signum, int checkctty);
gsignal(int pgid, int signum);
These functions post a signal to one or more processes. The
signum common to all three functions should be in the range
The psignal() function posts signal number signum to the
by the process structure p. With a few exceptions
the target process signal disposition is updated and is
runnable, so further handling of the signal is done in the
context of the
target process after a context switch. Note that psignal()
does not by
itself cause a context switch to happen.
The target process is not marked as runnable in the following cases:
+o The target process is sleeping uninterruptibly.
will be noticed when the process returns from the
+o The target process is currently ignoring the signal.
+o If a stop signal is sent to a sleeping process
that takes the
default action (see sigaction(2)), the process is
+o SIGCONT restarts a stopped process (or puts them
back to sleep)
regardless of the signal action (e.g., blocked or
If the target process is being traced, psignal() behaves as
if the target
process were taking the default action for signum. This allows the tracing
process to be notified of the signal.
The pgsignal() function posts signal number signum to each
member of the
process group described by pgrp. If checkctty is non-zero,
will be posted only to processes that have a controlling
pgrp is NULL no action is taken.
The gsignal() function posts signal number signum to each
member of the
process group identified by the group id pgid. If pgid is
zero no action
These functions are implemented in the file
OpenBSD 3.6 June 22, 1996
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