NetBSD/lib/libpthread/pthreads/fd_kern.c

648 lines
17 KiB
C

/* ==== fd_kern.c ============================================================
* Copyright (c) 1993, 1994 by Chris Provenzano, proven@mit.edu
* 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 Chris Provenzano.
* 4. The name of Chris Provenzano may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``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 CHRIS PROVENZANO 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.
*
* Description : Deals with the valid kernel fds.
*
* 1.00 93/09/27 proven
* -Started coding this file.
*
* 1.01 93/11/13 proven
* -The functions readv() and writev() added.
*/
#ifndef lint
static const char rcsid[] = "$Id: fd_kern.c,v 1.3 1994/02/07 22:04:16 proven Exp $ $provenid: fd_kern.c,v 1.7 1994/02/07 02:18:49 proven Exp $";
#endif
#include <pthread.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <stdarg.h>
#include <signal.h>
#include <fcntl.h>
#include <errno.h>
#include <pthread/posix.h>
/* ==========================================================================
* Variables used by both fd_kern_poll and fd_kern_wait
*/
static struct pthread *fd_wait_read, *fd_wait_write;
static fd_set fd_set_read, fd_set_write;
/* ==========================================================================
* fd_kern_poll()
*
* Called only from context_switch(). The kernel must be locked.
*
* This function uses a linked list of waiting pthreads, NOT a queue.
*/
static semaphore fd_wait_lock = SEMAPHORE_CLEAR;
void fd_kern_poll()
{
struct timeval __fd_kern_poll_timeout = { 0, 0 };
struct pthread **pthread;
semaphore *lock;
int count;
/* If someone has the lock then they are in RUNNING state, just return */
lock = &fd_wait_lock;
if (SEMAPHORE_TEST_AND_SET(lock)) {
return;
}
if (fd_wait_read || fd_wait_write) {
for (pthread = &fd_wait_read; *pthread; pthread = &((*pthread)->next)) {
FD_SET((*pthread)->fd, &fd_set_read);
}
for (pthread = &fd_wait_write; *pthread; pthread = &((*pthread)->next)) {
FD_SET((*pthread)->fd, &fd_set_write);
}
if ((count = machdep_sys_select(dtablesize, &fd_set_read,
&fd_set_write, NULL, &__fd_kern_poll_timeout)) < OK) {
if (count == -EINTR) {
SEMAPHORE_RESET(lock);
return;
}
PANIC();
}
for (pthread = &fd_wait_read; count && *pthread; ) {
if (FD_ISSET((*pthread)->fd, &fd_set_read)) {
/* Get lock on thread */
(*pthread)->state = PS_RUNNING;
*pthread = (*pthread)->next;
count--;
continue;
}
pthread = &((*pthread)->next);
}
for (pthread = &fd_wait_write; count && *pthread; ) {
if (FD_ISSET((*pthread)->fd, &fd_set_write)) {
semaphore *plock;
/* Get lock on thread */
plock = &(*pthread)->lock;
if (!(SEMAPHORE_TEST_AND_SET(plock))) {
/* Thread locked, skip it. */
(*pthread)->state = PS_RUNNING;
*pthread = (*pthread)->next;
SEMAPHORE_RESET(plock);
}
count--;
continue;
}
pthread = &((*pthread)->next);
}
}
SEMAPHORE_RESET(lock);
}
/* ==========================================================================
* fd_kern_wait()
*
* Called when there is no active thread to run.
*/
extern struct timeval __fd_kern_wait_timeout;
void fd_kern_wait()
{
struct pthread **pthread;
sigset_t sig_to_block;
int count;
if (fd_wait_read || fd_wait_write) {
for (pthread = &fd_wait_read; *pthread; pthread = &((*pthread)->next)) {
FD_SET((*pthread)->fd, &fd_set_read);
}
for (pthread = &fd_wait_write; *pthread; pthread = &((*pthread)->next)) {
FD_SET((*pthread)->fd, &fd_set_write);
}
/* Turn off interrupts for real while we set the timer. */
sigfillset(&sig_to_block);
sigprocmask(SIG_BLOCK, &sig_to_block, NULL);
machdep_unset_thread_timer();
__fd_kern_wait_timeout.tv_usec = 0;
__fd_kern_wait_timeout.tv_sec = 3600;
sigprocmask(SIG_UNBLOCK, &sig_to_block, NULL);
/*
* There is a small but finite chance that an interrupt will
* occure between the unblock and the select. Because of this
* sig_handler_real() sets the value of __fd_kern_wait_timeout
* to zero causing the select to do a poll instead of a wait.
*/
while ((count = machdep_sys_select(dtablesize, &fd_set_read,
&fd_set_write, NULL, &__fd_kern_wait_timeout)) < OK) {
if (count == -EINTR) {
return;
}
PANIC();
}
for (pthread = &fd_wait_read; count && *pthread; ) {
if (FD_ISSET((*pthread)->fd, &fd_set_read)) {
/* Get lock on thread */
(*pthread)->state = PS_RUNNING;
*pthread = (*pthread)->next;
count--;
continue;
}
pthread = &((*pthread)->next);
}
for (pthread = &fd_wait_write; count && *pthread; ) {
if (FD_ISSET((*pthread)->fd, &fd_set_write)) {
semaphore *plock;
/* Get lock on thread */
plock = &(*pthread)->lock;
if (!(SEMAPHORE_TEST_AND_SET(plock))) {
/* Thread locked, skip it. */
(*pthread)->state = PS_RUNNING;
*pthread = (*pthread)->next;
SEMAPHORE_RESET(plock);
}
count--;
continue;
}
pthread = &((*pthread)->next);
}
} else {
/* No threads, waiting on I/O, do a sigsuspend */
sig_handler_pause();
}
}
/* ==========================================================================
* Special Note: All operations return the errno as a negative of the errno
* listed in errno.h
* ======================================================================= */
/* ==========================================================================
* read()
*/
ssize_t __fd_kern_read(int fd, int flags, void *buf, size_t nbytes)
{
semaphore *lock, *plock;
int ret;
while ((ret = machdep_sys_read(fd, buf, nbytes)) < OK) {
if (ret == -EWOULDBLOCK) {
/* Lock queue */
lock = &fd_wait_lock;
while (SEMAPHORE_TEST_AND_SET(lock)) {
pthread_yield();
}
/* Lock pthread */
plock = &(pthread_run->lock);
while (SEMAPHORE_TEST_AND_SET(plock)) {
pthread_yield();
}
/* queue pthread for a FDR_WAIT */
pthread_run->next = fd_wait_read;
fd_wait_read = pthread_run;
pthread_run->fd = fd;
SEMAPHORE_RESET(lock);
reschedule(PS_FDR_WAIT);
} else {
pthread_run->error = -ret;
ret = NOTOK;
break;
}
}
return(ret);
}
/* ==========================================================================
* readv()
*/
int __fd_kern_readv(int fd, int flags, struct iovec *iov, int iovcnt)
{
semaphore *lock, *plock;
int ret;
while ((ret = machdep_sys_readv(fd, iov, iovcnt)) < OK) {
if (ret == -EWOULDBLOCK) {
/* Lock queue */
lock = &fd_wait_lock;
while (SEMAPHORE_TEST_AND_SET(lock)) {
pthread_yield();
}
/* Lock pthread */
plock = &(pthread_run->lock);
while (SEMAPHORE_TEST_AND_SET(plock)) {
pthread_yield();
}
/* queue pthread for a FDR_WAIT */
pthread_run->next = fd_wait_read;
fd_wait_read = pthread_run;
pthread_run->fd = fd;
SEMAPHORE_RESET(lock);
reschedule(PS_FDR_WAIT);
} else {
pthread_run->error = -ret;
ret = NOTOK;
break;
}
}
return(ret);
}
/* ==========================================================================
* write()
*/
ssize_t __fd_kern_write(int fd, int flags, const void *buf, size_t nbytes)
{
semaphore *lock, *plock;
int ret;
while ((ret = machdep_sys_write(fd, buf, nbytes)) < OK) {
if (pthread_run->error == -EWOULDBLOCK) {
/* Lock queue */
lock = &fd_wait_lock;
while (SEMAPHORE_TEST_AND_SET(lock)) {
pthread_yield();
}
/* Lock pthread */
plock = &(pthread_run->lock);
while (SEMAPHORE_TEST_AND_SET(plock)) {
pthread_yield();
}
/* queue pthread for a FDW_WAIT */
pthread_run->next = fd_wait_write;
fd_wait_write = pthread_run;
pthread_run->fd = fd;
SEMAPHORE_RESET(lock);
reschedule(PS_FDW_WAIT);
} else {
pthread_run->error = ret;
break;
}
}
return(ret);
}
/* ==========================================================================
* writev()
*/
int __fd_kern_writev(int fd, int flags, struct iovec *iov, int iovcnt)
{
semaphore *lock, *plock;
int ret;
while ((ret = machdep_sys_writev(fd, iov, iovcnt)) < OK) {
if (pthread_run->error == -EWOULDBLOCK) {
/* Lock queue */
lock = &fd_wait_lock;
while (SEMAPHORE_TEST_AND_SET(lock)) {
pthread_yield();
}
/* Lock pthread */
plock = &(pthread_run->lock);
while (SEMAPHORE_TEST_AND_SET(plock)) {
pthread_yield();
}
/* queue pthread for a FDW_WAIT */
pthread_run->next = fd_wait_write;
fd_wait_write = pthread_run;
pthread_run->fd = fd;
SEMAPHORE_RESET(lock);
reschedule(PS_FDW_WAIT);
} else {
pthread_run->error = ret;
break;
}
}
return(ret);
}
/* ==========================================================================
* For blocking version we really should set an interrupt
* fcntl()
*/
int __fd_kern_fcntl(int fd, int flags, int cmd, int arg)
{
return(machdep_sys_fcntl(fd, cmd, arg));
}
/* ==========================================================================
* close()
*/
int __fd_kern_close(int fd, int flags)
{
return(machdep_sys_close(fd));
}
/* ==========================================================================
* lseek()
*/
int __fd_kern_lseek(int fd, int flags, off_t offset, int whence)
{
return(machdep_sys_lseek(fd, offset, whence));
}
/*
* File descriptor operations
*/
extern machdep_sys_close();
/* Normal file operations */
static struct fd_ops __fd_kern_ops = {
__fd_kern_write, __fd_kern_read, __fd_kern_close, __fd_kern_fcntl,
__fd_kern_readv, __fd_kern_writev, __fd_kern_lseek
};
/* NFS file opperations */
/* FIFO file opperations */
/* Device operations */
/* ==========================================================================
* open()
*
* Because open could potentially block opening a file from a remote
* system, we want to make sure the call will timeout. We then try and open
* the file, and stat the file to determine what operations we should
* associate with the fd.
*
* This is not done yet
*
* A reqular file on the local system needs no special treatment.
*/
int open(const char *path, int flags, ...)
{
int fd, mode, fd_kern;
struct stat stat_buf;
va_list ap;
/* If pthread scheduling == FIFO set a virtual timer */
if (flags & O_CREAT) {
va_start(ap, flags);
mode = va_arg(ap, int);
va_end(ap);
} else {
mode = 0;
}
if (!((fd = fd_allocate()) < OK)) {
fd_table[fd]->flags = flags;
flags |= __FD_NONBLOCK;
if (!((fd_kern = machdep_sys_open(path, flags, mode)) < OK)) {
/* fstat the file to determine what type it is */
if (fstat(fd_kern, &stat_buf)) {
printf("error %d stating new fd %d\n", errno, fd);
}
if (S_ISREG(stat_buf.st_mode)) {
fd_table[fd]->ops = &(__fd_kern_ops);
fd_table[fd]->type = FD_HALF_DUPLEX;
} else {
fd_table[fd]->ops = &(__fd_kern_ops);
fd_table[fd]->type = FD_FULL_DUPLEX;
}
fd_table[fd]->fd = fd_kern;
return(fd);
}
pthread_run->error = - fd_kern;
fd_table[fd]->count = 0;
}
return(NOTOK);
}
/* ==========================================================================
* fd_kern_init()
*
* Assume the entry is locked before routine is invoked
*
* This may change. The problem is setting the fd to nonblocking changes
* the parents fd too, which may not be the desired result.
*/
static fd_kern_init_called = 0;
void fd_kern_init(int fd)
{
if ((fd_table[fd]->flags = machdep_sys_fcntl(fd, F_GETFL, NULL)) >= OK) {
machdep_sys_fcntl(fd, F_SETFL, fd_table[fd]->flags | __FD_NONBLOCK);
fd_table[fd]->ops = &(__fd_kern_ops);
fd_table[fd]->type = FD_HALF_DUPLEX;
fd_table[fd]->fd = fd;
fd_table[fd]->count = 1;
}
}
/* ==========================================================================
* Here are the berkeley socket functions. These are not POSIX.
* ======================================================================= */
/* ==========================================================================
* socket()
*/
int socket(int af, int type, int protocol)
{
int fd, fd_kern;
if (!((fd = fd_allocate()) < OK)) {
if (!((fd_kern = machdep_sys_socket(af, type, protocol)) < OK)) {
machdep_sys_fcntl(fd_kern, F_SETFL, __FD_NONBLOCK);
/* Should fstat the file to determine what type it is */
fd_table[fd]->ops = & __fd_kern_ops;
fd_table[fd]->type = FD_FULL_DUPLEX;
fd_table[fd]->fd = fd_kern;
fd_table[fd]->flags = 0;
return(fd);
}
pthread_run->error = - fd_kern;
fd_table[fd]->count = 0;
}
return(NOTOK);
}
/* ==========================================================================
* bind()
*/
int bind(int fd, const struct sockaddr *name, int namelen)
{
/* Not much to do in bind */
semaphore *plock;
int ret;
if ((ret = fd_lock(fd, FD_RDWR)) == OK) {
if ((ret = machdep_sys_bind(fd_table[fd]->fd, name, namelen)) < OK) {
pthread_run->error = - ret;
}
fd_unlock(fd, FD_RDWR);
}
return(ret);
}
/* ==========================================================================
* connect()
*/
int connect(int fd, const struct sockaddr *name, int namelen)
{
semaphore *lock, *plock;
struct sockaddr tmpname;
int ret, tmpnamelen;
if ((ret = fd_lock(fd, FD_RDWR)) == OK) {
if ((ret = machdep_sys_connect(fd_table[fd]->fd, name, namelen)) < OK) {
if ((ret == -EWOULDBLOCK) || (ret == -EINPROGRESS) ||
(ret == -EALREADY)) {
/* Lock queue */
lock = &fd_wait_lock;
while (SEMAPHORE_TEST_AND_SET(lock)) {
pthread_yield();
}
/* Lock pthread */
plock = &(pthread_run->lock);
while (SEMAPHORE_TEST_AND_SET(plock)) {
pthread_yield();
}
/* queue pthread for a FDW_WAIT */
pthread_run->fd = fd_table[fd]->fd.i;
pthread_run->next = fd_wait_write;
fd_wait_write = pthread_run;
SEMAPHORE_RESET(lock);
reschedule(PS_FDW_WAIT);
/* OK now lets see if it really worked */
if (((ret = machdep_sys_getpeername(fd_table[fd]->fd,
&tmpname, &tmpnamelen)) < OK) && (ret == -ENOTCONN)) {
/* Get the error, this function should not fail */
machdep_sys_getsockopt(fd_table[fd]->fd, SOL_SOCKET,
SO_ERROR, &pthread_run->error, &tmpnamelen);
}
} else {
pthread_run->error = -ret;
}
}
fd_unlock(fd, FD_RDWR);
}
return(ret);
}
/* ==========================================================================
* accept()
*/
int accept(int fd, struct sockaddr *name, int *namelen)
{
semaphore *lock, *plock;
int ret, fd_kern;
if ((ret = fd_lock(fd, FD_RDWR)) == OK) {
while ((fd_kern = machdep_sys_accept(fd_table[fd]->fd, name, namelen)) < OK) {
if (fd_kern == -EWOULDBLOCK) {
/* Lock queue */
lock = &fd_wait_lock;
while (SEMAPHORE_TEST_AND_SET(lock)) {
pthread_yield();
}
/* Lock pthread */
plock = &(pthread_run->lock);
while (SEMAPHORE_TEST_AND_SET(plock)) {
pthread_yield();
}
/* queue pthread for a FDR_WAIT */
pthread_run->fd = fd_table[fd]->fd.i;
pthread_run->next = fd_wait_write;
pthread_run->next = fd_wait_read;
fd_wait_read = pthread_run;
SEMAPHORE_RESET(lock);
reschedule(PS_FDR_WAIT);
} else {
fd_unlock(fd, FD_RDWR);
return(fd_kern);
}
}
fd_unlock(fd, FD_RDWR);
if (!((ret = fd_allocate()) < OK)) {
/* This may be unnecessary */
machdep_sys_fcntl(fd_kern, F_SETFL, __FD_NONBLOCK);
/* Should fstat the file to determine what type it is */
fd_table[ret]->ops = & __fd_kern_ops;
fd_table[ret]->type = FD_FULL_DUPLEX;
fd_table[ret]->fd = fd_kern;
fd_table[ret]->flags = 0;
}
}
return(ret);
}
/* ==========================================================================
* listen()
*/
int listen(int fd, int backlog)
{
int ret;
if ((ret = fd_lock(fd, FD_RDWR)) == OK) {
ret = machdep_sys_listen(fd_table[fd]->fd, backlog);
fd_unlock(fd, FD_RDWR);
}
return(ret);
}