poll() as a system call

6 files changed, 389 insertions, 8 deletions

diff --git a/include/poll.h b/include/poll.h
new file mode 100644
index 00000000000..dfc7dc21aa2
--- /dev/null
+++ b/include/poll.h
@@ -0,0 +1,7 @@
+/*	$OpenBSD: poll.h,v 1.1 1996/05/18 08:53:07 deraadt Exp $ */
+
+/*
+ * Typical poll() implimentations expect poll.h to be in /usr/include. 
+ * However this is not a convenient place for the real definitions.
+ */
+#include <sys/poll.h>
diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc
index 0f308371e19..179e6a92ab8 100644
--- a/lib/libc/sys/Makefile.inc
+++ b/lib/libc/sys/Makefile.inc
@@ -100,12 +100,13 @@ MAN+=	accept.2 access.2 acct.2 adjtime.2 bind.2 brk.2 chdir.2 chflags.2 \
 	listen.2 lseek.2 mkdir.2 mkfifo.2 mknod.2 madvise.2 mincore.2 \
 	minherit.2 mlock.2 \
 	mmap.2 mount.2 mprotect.2 msync.2 munmap.2 nfssvc.2 open.2 pathconf.2 \
-	pipe.2 profil.2 ptrace.2 quotactl.2 read.2 readlink.2 reboot.2 recv.2 \
-	rename.2 revoke.2 rfork.2 rmdir.2 select.2 send.2 setgroups.2 setpgid.2 \
-	setsid.2 setuid.2 shutdown.2 sigaction.2 sigaltstack.2 sigpending.2 \
-	sigprocmask.2 sigreturn.2 sigstack.2 sigsuspend.2 socket.2 \
-	socketpair.2 stat.2 statfs.2 swapon.2 symlink.2 sync.2 sysarch.2 \
-	syscall.2 truncate.2 umask.2 unlink.2 utimes.2 vfork.2 wait.2 write.2
+	pipe.2 profil.2 poll.2 ptrace.2 quotactl.2 read.2 readlink.2 reboot.2 \
+	recv.2 rename.2 revoke.2 rfork.2 rmdir.2 select.2 send.2 setgroups.2 \
+	setpgid.2 setsid.2 setuid.2 shutdown.2 sigaction.2 sigaltstack.2 \
+	sigpending.2 sigprocmask.2 sigreturn.2 sigstack.2 sigsuspend.2 \
+	socket.2 socketpair.2 stat.2 statfs.2 swapon.2 symlink.2 sync.2 \
+	sysarch.2 syscall.2 truncate.2 umask.2 unlink.2 utimes.2 vfork.2 \
+	wait.2 write.2
 
 MAN+=	msgctl.2 shmctl.2 shmat.2 semop.2 semget.2 semctl.2 msgsnd.2 msgrcv.2 \
 	msgget.2 shmget.2
diff --git a/lib/libc/sys/poll.2 b/lib/libc/sys/poll.2
new file mode 100644
index 00000000000..f07df83eaec
--- /dev/null
+++ b/lib/libc/sys/poll.2
@@ -0,0 +1,199 @@
+.\"
+.\" Copyright (c) 1994 Jason R. Thorpe
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by Jason R. Thorpe.
+.\" 4. The name of the author may not be used to endorse or promote products
+.\"    derived from this software without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\"
+.Dd December 13, 1994
+.Dt POLL 2
+.Os
+.Sh NAME
+.Nm poll
+.Nd synchronous I/O multiplexing
+.Sh SYNOPSIS
+.Fd #include <poll.h>
+.Ft int
+.Fn poll "struct pollfd *fds" "int nfds" "int timeout"
+.Sh DESCRIPTION
+.Fn Poll
+provides a mechanism for reporting I/O conditions across a set of file
+descriptors.
+.Pp
+The arguments are as follows:
+.Bl -tag -width timeout
+.It Pa fds
+Points to an array of
+.Nm pollfd
+structures, which are defined as:
+.Bd -literal -offset indent
+struct pollfd {
+	int fd;
+	short events;
+	short revents;
+};
+.Ed
+.Pp
+The
+.Pa fd
+member is an open file descriptor.  The
+.Pa events
+and
+.Pa revents
+members are bitmasks of conditions to monitor and conditions found,
+respectively.
+.It Pa nfds
+The number of
+.Nm pollfd
+structures in the array.
+.It Pa timeout
+Maximum interval to wait for the poll to complete, in milliseconds.  If
+this value is 0, then
+.Fn poll
+will return immediately.  If this value is less than 0,
+.Fn poll
+will block indefinitely until a condition is found.
+.El
+.Pp
+The calling process sets the
+.Pa events
+bitmask and
+.Fn poll
+sets the
+.Pa revents
+bitmask.  Each call to
+.Fn poll
+resets the
+.Pa revents
+bitmask for accuracy.  The condition flags in the bitmasks are defined as:
+.Bl -tag -width POLLRDNORM
+.It Nm POLLIN
+Data is available on the file descriptor for reading.
+.It Nm POLLNORM
+Same as
+.Nm POLLIN .
+.It Nm POLLPRI
+Same as
+.Nm POLLIN .
+.It Nm POLLOUT
+Data can be written to the file descriptor without blocking.
+.It Nm POLLERR
+This flag is not used in this implementation and is provided only for source
+code compatibility.
+.It Nm POLLHUP
+The file descriptor was valid before the polling process and invalid after.
+Presumably, this means that the file descriptor was closed sometime during
+the poll.
+.It Nm POLLNVAL
+The corresponding file descriptor is invalid.
+.It Nm POLLRDNORM
+Same as
+.Nm POLLIN .
+.It Nm POLLRDBAND
+Same as
+.Nm POLLIN .
+.It Nm POLLWRNORM
+Same as
+.Nm POLLOUT .
+.It Nm POLLWRBAND
+Same as
+.Nm POLLOUT .
+.It Nm POLLMSG
+This flag is not used in this implementation and is provided only for source
+code compatibility.
+.El
+.Pp
+All flags except
+.Nm POLLIN ,
+.Nm POLLOUT ,
+and their synonyms are for use only in the
+.Pa revents
+member of the
+.Nm pollfd
+structure.  An attempt to set any of these flags in the
+.Pa events
+member will generate an error condition.
+.Pp
+In addition to I/O multiplexing,
+.Fn poll
+can be used to generate simple timeouts.  This functionality may be achieved
+by passing a NULL pointer for
+.Pa fds .
+.Sh WARNINGS
+Since this implementation is a wrapper around
+.Fn select ,
+functionality is limited to such.  There is no differentiation between
+standard and priority messages in the read or write queues.
+.Pp
+The
+.Nm POLLHUP
+flag is only a close approximation and may not always be accurate.
+.Sh RETURN VALUES
+Upon error,
+.Fn poll
+returns a -1 and sets the global variable
+.Pa errno
+to indicate the error.  If the timeout interval was reached before any events
+occurred, a 0 is returned.  Otherwise,
+.Fn poll
+returns the number of file descriptors for which
+.Pa revents
+is non-zero.
+.Sh ERRORS
+.Fn Poll
+will fail if:
+.Bl -tag -width "EINVAL   "
+.It Bq Er EINVAL
+.Pa nfds
+was either a negative number or greater than the number of available
+file descriptors.
+.It Bq Er EINVAL
+An invalid flags was set in the
+.Pa events
+member of the
+.Nm pollfd
+structure.
+.It Bq Er EINVAL
+The timeout passed to
+.Fn select
+was too large.
+.It Bq Er EAGAIN
+Resource allocation failed inside of
+.Fn poll .
+Subsequent calls to
+.Fn poll
+may succeed.
+.It Bq Er EINTR
+.Fn Select
+caught a signal during the polling process.
+.El
+.Sh SEE ALSO
+.Xr sysconf 3 ,
+.Xr select 2
+.Sh HISTORY
+A
+.Fn poll
+system call appeared in
+.At V
diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c
index 9c5fbe7cd00..ffb8235b251 100644
--- a/sys/kern/sys_generic.c
+++ b/sys/kern/sys_generic.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sys_generic.c,v 1.4 1996/05/07 05:52:01 deraadt Exp $	*/
+/*	$OpenBSD: sys_generic.c,v 1.5 1996/05/18 08:53:09 deraadt Exp $	*/
 /*	$NetBSD: sys_generic.c,v 1.24 1996/03/29 00:25:32 cgd Exp $	*/
 
 /*
@@ -53,6 +53,7 @@
 #include <sys/kernel.h>
 #include <sys/stat.h>
 #include <sys/malloc.h>
+#include <sys/poll.h>
 #ifdef KTRACE
 #include <sys/ktrace.h>
 #endif
@@ -62,6 +63,7 @@
 
 int selscan __P((struct proc *, fd_set *, fd_set *, int, register_t *));
 int seltrue __P((dev_t, int, struct proc *));
+void pollscan __P((struct proc *, struct pollfd *, int, register_t *));
 
 /*
  * Read system call.
@@ -757,3 +759,123 @@ selwakeup(sip)
 		splx(s);
 	}
 }
+
+void
+pollscan(p, pl, nfd, retval)
+	struct proc *p;
+	struct pollfd *pl;
+	int nfd;
+	register_t *retval;
+{
+	register struct filedesc *fdp = p->p_fd;
+	register int msk, i;
+	struct file *fp;
+	int n = 0;
+	static int flag[3] = { FREAD, FWRITE, 0 };
+	static int pflag[3] = { POLLIN|POLLRDNORM, POLLOUT, POLLERR };
+
+	/* 
+	 * XXX: We need to implement the rest of the flags.
+	 */
+	for (i = 0; i < nfd; i++) {
+		fp = fdp->fd_ofiles[pl[i].fd];
+		if (fp == NULL) {
+			if (pl[i].events & POLLNVAL) {
+				pl[i].revents |= POLLNVAL;
+				n++;
+			}
+			continue;
+		}
+		for (msk = 0; msk < 3; msk++) {
+			if (pl[i].events & pflag[msk]) {
+				if ((*fp->f_ops->fo_select)(fp, flag[msk], p)) {
+					pl[i].revents |= pflag[msk] &
+					    pl[i].events;
+					n++;
+				}
+			}
+		}
+	}
+	*retval = n;
+}
+
+/*
+ * We are using the same mechanism as select only we encode/decode args
+ * differently.
+ */
+int
+sys_poll(p, v, retval)
+	register struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_poll_args *uap = v;
+	size_t sz = sizeof(struct pollfd) * SCARG(uap, nfds);
+	struct pollfd *pl;
+	int msec = SCARG(uap, timeout);
+	struct timeval atv;
+	int timo, ncoll, i, s, error, error2;
+	extern int nselcoll, selwait;
+
+	pl = (struct pollfd *) malloc(sz, M_TEMP, M_WAITOK);
+
+	if ((error = copyin(SCARG(uap, fds), pl, sz)) != 0)
+		goto bad;
+
+	for (i = 0; i < SCARG(uap, nfds); i++)
+		pl[i].revents = 0;
+
+	if (msec != -1) {
+		atv.tv_sec = msec / 1000;
+		atv.tv_usec = (msec - (atv.tv_sec * 1000)) * 1000;
+
+		if (itimerfix(&atv)) {
+			error = EINVAL;
+			goto done;
+		}
+		s = splclock();
+		timeradd(&atv, &time, &atv);
+		timo = hzto(&atv);
+		/*
+		 * Avoid inadvertently sleeping forever.
+		 */
+		if (timo == 0)
+			timo = 1;
+		splx(s);
+	} else
+		timo = 0;
+
+retry:
+	ncoll = nselcoll;
+	p->p_flag |= P_SELECT;
+	pollscan(p, pl, SCARG(uap, nfds), retval);
+	if (*retval)
+		goto done;
+	s = splhigh();
+	if (timo && timercmp(&time, &atv, >=)) {
+		splx(s);
+		goto done;
+	}
+	if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) {
+		splx(s);
+		goto retry;
+	}
+	p->p_flag &= ~P_SELECT;
+	error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "poll", timo);
+	splx(s);
+	if (error == 0)
+		goto retry;
+
+done:
+	p->p_flag &= ~P_SELECT;
+	/* poll is not restarted after signals... */
+	if (error == ERESTART)
+		error = EINTR;
+	if (error == EWOULDBLOCK)
+		error = 0;
+	if ((error2 = copyout(pl, SCARG(uap, fds), sz)) != 0)
+		error = error2;
+bad:
+	free((char *) pl, M_TEMP);
+	return (error);
+}
diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index 8f5c8934aea..c1767a2de19 100644
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -1,4 +1,4 @@
-	$OpenBSD: syscalls.master,v 1.8 1996/05/02 13:09:50 deraadt Exp $
+	$OpenBSD: syscalls.master,v 1.9 1996/05/18 08:53:10 deraadt Exp $
 ;	$NetBSD: syscalls.master,v 1.32 1996/04/23 10:24:21 mycroft Exp $
 
 ;	@(#)syscalls.master	8.2 (Berkeley) 1/13/94
@@ -37,6 +37,7 @@
 #include <sys/signal.h>
 #include <sys/mount.h>
 #include <sys/syscallargs.h>
+#include <sys/poll.h>
 
 ; Reserved/unimplemented system calls in the range 0-150 inclusive
 ; are reserved for use in future Berkeley releases.
@@ -452,3 +453,5 @@
 250	STD		{ int sys_minherit(caddr_t addr, size_t len, \
 			    int inherit); }
 251	STD		{ int sys_rfork(int flags); }
+252	STD		{ int sys_poll(struct pollfd *fds, unsigned long nfds, \
+			    int timeout); }
diff --git a/sys/sys/poll.h b/sys/sys/poll.h
new file mode 100644
index 00000000000..97160d848c2
--- /dev/null
+++ b/sys/sys/poll.h
@@ -0,0 +1,49 @@
+/*	$OpenBSD: poll.h,v 1.1 1996/05/18 08:53:08 deraadt Exp $ */
+
+/*
+ * Copyright (c) 1996 Theo de Raadt
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef	_SYS_POLL_H_
+#define	_SYS_POLL_H_
+
+struct pollfd {
+	int 	fd;
+	short	events;
+	short	revents;
+};
+
+#define	POLLIN		0x0001
+#define	POLLPRI		0x0002
+#define	POLLOUT		0x0004
+#define	POLLERR		0x0008
+#define	POLLHUP		0x0010
+#define	POLLNVAL	0x0020
+#define	POLLRDNORM	0x0040
+#define	POLLRDBAND	0x0080
+#define	POLLWRBAND	0x0100
+
+#endif /* !_SYS_POLL_H_ */