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fsetown(9) [netbsd man page]

FSETOWN(9)						   BSD Kernel Developer's Manual						FSETOWN(9)

fsetown, fgetown, fownsignal -- file descriptor owner handling functions SYNOPSIS
#include <sys/file.h> int fsetown(struct lwp *l, pid_t *pgid, int cmd, const void *data); int fgetown(struct lwp *l, pid_t pgid, int cmd, void *data); void fownsignal(pid_t pgid, int signo, int code, int band, void *fdescdata); DESCRIPTION
These functions handle file descriptor owner related ioctls and related signal delivery. Device drivers and other parts of the kernel call these functions from ioctl entry functions or I/O notification functions. fsetown() sets the owner of file. cmd is an ioctl command, one of SIOCSPGRP, FIOSETOWN, and TIOCSPGRP. data is interpreted as a pointer to a signed integer, the integer being the ID of the owner. The cmd determines how exactly data should be interpreted. If cmd is TIOCSPGRP, the ID needs to be positive and is interpreted as process group ID. For SIOCSPGRP and FIOSETOWN, the passed ID is the process ID if posi- tive, or the process group ID if negative. fgetown() returns the current owner of the file. cmd is an ioctl command, one of SIOCGPGRP, FIOGETOWN, and TIOCGPGRP. data is interpreted as a pointer to a signed integer, and the value is set according to the passed cmd. For TIOCGPGRP, the returned data value is positive process group ID if the owner is the process group, or negative process ID if the owner is a process. For other ioctls, the returned value is the positive process ID if the owner is a process, or the negative process group ID if the owner is a process group. fownsignal() schedules the signo signal to be sent to the current file descriptor owner. The signals typically used with this function are SIGIO and SIGURG. The code and band arguments are sent along with the signal as additional signal specific information if SA_SIGINFO is activated. If the information is not available from the context of the fownsignal() call, these should be passed as zero. fdescdata is used to lookup the file descriptor for SA_SIGINFO signals. If it is specified, the file descriptor number is sent along with the signal as addi- tional signal specific information. If file descriptor data pointer is not available in the context of the fownsignal() call, NULL should be used instead. Note that a fcntl(2) F_SETOWN request is translated by the kernel to a FIOSETOWN ioctl, and F_GETOWN is translated to FIOGETOWN. This is done transparently by generic code, before the device- or subsystem-specific ioctl entry function is called. SEE ALSO
fcntl(2), siginfo(2), signal(7), ioctl(9), signal(9) HISTORY
These kernel functions appeared in NetBSD 2.0. BSD
December 20, 2005 BSD

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PSIGNAL(9)						   BSD Kernel Developer's Manual						PSIGNAL(9)

psignal, pgsignal, gsignal -- post signal to a process or process group SYNOPSIS
#include <sys/types.h> #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: o The target process is sleeping uninterruptibly. The signal will be noticed when the process returns from the system call or trap. 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 stopped without awakening it. o SIGCONT restarts a stopped process (or puts them back to sleep) regardless of the signal action (e.g., blocked or ignored). 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, the sig- nal will be posted only to processes that have a controlling terminal. pgsignal() is implemented by walking along the process list headed by the field pg_members of the process group structure pointed at by pgrp and calling psignal() as appropriate. If 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. 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) BSD
June 22, 1996 BSD
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