table of contents
|PSIGNAL(9)||Kernel Developer's Manual||PSIGNAL(9)|
NAME¶psignal, pgsignal, gsignal — post signal to a process or process group
#include <sys/signalvar.h> void
psignal(struct proc *p, int signum); void
pgsignal(struct pgrp *pgrp, int signum, int checkctty); void
gsignal(int pgid, int signum);
DESCRIPTION¶These functions post a signal to one or more processes. The argument signum common to all three functions should be in the range [1-
NSIG]. The psignal() function posts signal number signum to the process represented by the process structure p. With a few exceptions noted below, the target process signal disposition is updated and is marked as 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:
- The target process is sleeping uninterruptibly. The signal will be noticed when the process returns from the system call or trap.
- The target process is currently ignoring the signal.
- If a stop signal is sent to a sleeping process that takes the default action (see sigaction(2)), the process is stopped without awakening it.
SIGCONTrestarts a stopped process (or puts them back to sleep) regardless of the signal action (e.g., blocked or ignored).
pg_membersof the process group structure pointed at by pgrp and calling psignal() as appropriate. If pgrp is
NULLno action is taken. The gsignal() function posts signal number signum to each member of the process group identified by the group id pgid. gsignal() first finds the group structure associated with pgid, then invokes pgsignal() with the argument checkctty set to zero. If pgid is zero no action is taken.
SEE ALSO¶sigaction(2), signal(9), tsleep(9)
|June 22, 1996||Debian|