Add select(2).

libc/Makefile

@@ -223,6 +223,7 @@ rename.o \
 rmdir.o \
 sbrk.o \
 scanf.o \
+select.o \
 setjmp.o \
 setlocale.o \
 settermmode.o \

libc/include/sys/select.h

@@ -0,0 +1,68 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    sys/select.h
+    Waiting on multiple file descriptors.
+
+*******************************************************************************/
+
+
+#ifndef _SYS_SELECT_H
+#define _SYS_SELECT_H 1
+
+#include <features.h>
+#include <string.h> /* TODO: HACK: for FD_ZERO */
+
+__BEGIN_DECLS
+
+@include(time_t.h)
+@include(suseconds_t.h)
+
+__BEGIN_DECLS
+#include <sortix/sigset.h>
+#include <sortix/timespec.h>
+#include <sortix/timeval.h>
+__END_DECLS
+
+#define FD_SETSIZE 1024
+#define __FD_ELEM_SIZE ((int) sizeof(__fd_mask))
+#define __FD_ELEM_BITS (8 * __FD_ELEM_SIZE)
+typedef long int __fd_mask;
+typedef struct
+{
+	__fd_mask __fds_bits[FD_SETSIZE / (8 * (int) sizeof(__fd_mask))];
+} fd_set;
+
+#define __FD_INDEX(fd) ((fd) / __FD_ELEM_BITS)
+#define __FD_EXPONENT(fd) ((__fd_mask) (fd) % __FD_ELEM_BITS)
+#define __FD_MASK(fd) (1 << __FD_EXPONENT(fd))
+#define __FD_ACCESS(fd, fdsetp) ((fdsetp)->__fds_bits[__FD_INDEX(fd)])
+
+#define FD_CLR(fd, fdsetp) (__FD_ACCESS(fd, fdsetp) &= ~__FD_MASK(fd))
+#define FD_ISSET(fd, fdsetp) (__FD_ACCESS(fd, fdsetp) & __FD_MASK(fd))
+#define FD_SET(fd, fdsetp) (__FD_ACCESS(fd, fdsetp) |= __FD_MASK(fd))
+#define FD_ZERO(fdsetp) memset(fdsetp, 0, sizeof(fd_set))
+
+/* TODO: pselect */
+int select(int, fd_set* restrict, fd_set* restrict, fd_set* restrict,
+           struct timeval* restrict);
+
+__END_DECLS
+
+#endif

libc/select.cpp

@@ -0,0 +1,73 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    select.cpp
+    Waiting on multiple file descriptors.
+
+*******************************************************************************/
+
+#include <sys/select.h>
+
+#include <poll.h>
+
+extern "C"
+int select(int nfds, fd_set* restrict readfds, fd_set* restrict writefds,
+           fd_set* restrict exceptfds, struct timeval* restrict timeout)
+{
+	const int READ_EVENTS = POLLIN | POLLRDNORM;
+	const int WRITE_EVENTS = POLLOUT | POLLWRNORM;
+	const int EXCEPT_EVENTS = POLLERR | POLLHUP;
+	struct pollfd fds[FD_SETSIZE];
+	for ( int i = 0; i < nfds; i++ )
+	{
+		fds[i].fd = i;
+		fds[i].events = fds[i].revents = 0;
+		if ( FD_ISSET(i, readfds) )
+			fds[i].events |= READ_EVENTS;
+		if ( FD_ISSET(i, writefds) )
+			fds[i].events |= WRITE_EVENTS;
+		if ( FD_ISSET(i, exceptfds) )
+			fds[i].events |= EXCEPT_EVENTS;
+		if ( !fds[i].events )
+			fds[i].fd = -1;
+	}
+	struct timespec* timeout_tsp = NULL;
+	struct timespec timeout_ts;
+	if ( timeout )
+		timeout_tsp = &timeout_ts,
+		timeout_tsp->tv_sec = timeout->tv_sec,
+		timeout_tsp->tv_nsec = (long) timeout->tv_usec * 1000;
+	int num_occur = ppoll(fds, nfds, timeout_tsp, NULL);
+	if ( num_occur < 0 )
+		return -1;
+	if ( readfds ) FD_ZERO(readfds);
+	if ( writefds ) FD_ZERO(writefds);
+	if ( exceptfds ) FD_ZERO(exceptfds);
+	int ret = 0;
+	for ( int i = 0; i < nfds; i++ )
+	{
+		if ( !fds[i].events )
+			continue;
+		int events = fds[i].revents;
+		if ( events & READ_EVENTS && readfds ) { FD_SET(i, readfds); ret++; }
+		if ( events & WRITE_EVENTS && writefds ) { FD_SET(i, writefds); ret++; }
+		if ( events & EXCEPT_EVENTS && exceptfds ) { FD_SET(i, exceptfds); ret++; }
+	}
+	return ret;
+}