freebsd-dev/lib/libc_r/uthread/uthread_fd.c
Julian Elischer 0f7d684755 Submitted by: John Birrell <cimaxp1!jb@werple.net.au>
Here are the diffs for libc_r to get it one step closer to P1003.1c
These make most of the thread/mutex/condvar structures opaque to the
user. There are three functions which have been renamed with _np
suffixes because they are extensions to P1003.1c (I did them for JAVA,
which needs to suspend/resume threads and also start threads suspended).

I've created a new header (pthread_np.h) for the non-POSIX stuff.

The egrep tags stuff in /usr/src/lib/libc_r/Makefile that I uncommented
doesn't work. I think its best to delete it. I don't think libc_r needs
tags anyway, 'cause most of the source is in libc which does have tags.

also:

Here's the first batch of man pages for the thread functions.
The diff to /usr/src/lib/libc_r/Makefile removes some stuff that was
inherited from /usr/src/lib/libc/Makefile that should only be done with
libc.

also:

I should have sent this diff with the pthread(3) man page.
It allows people to type

make -DWANT_LIBC_R world

to get libc_r built with the rest of the world. I put this in the
pthread(3) man page.  The default is still not to build libc_r.


also:
The diff attached adds a pthread(3) man page to /usr/src/share/man/man3.
The idea is that without libc_r installed, this man page will give people
enough info to know that they have to build libc_r.
1996-08-20 08:22:01 +00:00

379 lines
11 KiB
C

/*
* Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
* 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 John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
*/
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
int
_thread_fd_table_init(int fd)
{
int ret = 0;
int status;
/* Block signals: */
_thread_kern_sig_block(&status);
/* Check if the file descriptor is out of range: */
if (fd < 0 || fd >= _thread_dtablesize) {
/* Return a bad file descriptor error: */
errno = EBADF;
ret = -1;
}
/*
* Check if memory has already been allocated for this file
* descriptor:
*/
else if (_thread_fd_table[fd] != NULL) {
}
/* Allocate memory for the file descriptor table entry: */
else if ((_thread_fd_table[fd] = (struct fd_table_entry *) malloc(sizeof(struct fd_table_entry))) == NULL) {
/* Return a bad file descriptor error: */
errno = EBADF;
ret = -1;
} else {
/* Initialise the file locks: */
_thread_fd_table[fd]->r_owner = NULL;
_thread_fd_table[fd]->w_owner = NULL;
_thread_fd_table[fd]->r_fname = NULL;
_thread_fd_table[fd]->w_fname = NULL;
_thread_fd_table[fd]->r_lineno = 0;;
_thread_fd_table[fd]->w_lineno = 0;;
_thread_fd_table[fd]->r_lockcount = 0;;
_thread_fd_table[fd]->w_lockcount = 0;;
/* Initialise the read/write queues: */
_thread_queue_init(&_thread_fd_table[fd]->r_queue);
_thread_queue_init(&_thread_fd_table[fd]->w_queue);
/* Get the flags for the file: */
if ((_thread_fd_table[fd]->flags = _thread_sys_fcntl(fd, F_GETFL, 0)) == -1) {
ret = -1;
/* Make the file descriptor non-blocking: */
} else {
_thread_sys_fcntl(fd, F_SETFL, _thread_fd_table[fd]->flags | O_NONBLOCK);
}
/* Check if one of the fcntl calls failed: */
if (ret == -1) {
/* Free the file descriptor table entry: */
free(_thread_fd_table[fd]);
_thread_fd_table[fd] = NULL;
}
}
/* Unblock signals: */
_thread_kern_sig_unblock(status);
/* Return the completion status: */
return (ret);
}
void
_thread_fd_unlock(int fd, int lock_type)
{
int ret;
int status;
/* Block signals while the file descriptor lock is tested: */
_thread_kern_sig_block(&status);
/*
* Check that the file descriptor table is initialised for this
* entry:
*/
if ((ret = _thread_fd_table_init(fd)) != 0) {
} else {
/* Check if the running thread owns the read lock: */
if (_thread_fd_table[fd]->r_owner == _thread_run) {
/* Check the file descriptor and lock types: */
if (lock_type == FD_READ || lock_type == FD_RDWR) {
/*
* Decrement the read lock count for the
* running thread:
*/
_thread_fd_table[fd]->r_lockcount--;
/*
* Check if the running thread still has read
* locks on this file descriptor:
*/
if (_thread_fd_table[fd]->r_lockcount != 0) {
}
/*
* Get the next thread in the queue for a
* read lock on this file descriptor:
*/
else if ((_thread_fd_table[fd]->r_owner = _thread_queue_deq(&_thread_fd_table[fd]->r_queue)) == NULL) {
} else {
/*
* Set the state of the new owner of
* the thread to running:
*/
_thread_fd_table[fd]->r_owner->state = PS_RUNNING;
/*
* Reset the number of read locks.
* This will be incremented by the
* new owner of the lock when it sees
* that it has the lock.
*/
_thread_fd_table[fd]->r_lockcount = 0;
}
}
}
/* Check if the running thread owns the write lock: */
if (_thread_fd_table[fd]->w_owner == _thread_run) {
/* Check the file descriptor and lock types: */
if (lock_type == FD_WRITE || lock_type == FD_RDWR) {
/*
* Decrement the write lock count for the
* running thread:
*/
_thread_fd_table[fd]->w_lockcount--;
/*
* Check if the running thread still has
* write locks on this file descriptor:
*/
if (_thread_fd_table[fd]->w_lockcount != 0) {
}
/*
* Get the next thread in the queue for a
* write lock on this file descriptor:
*/
else if ((_thread_fd_table[fd]->w_owner = _thread_queue_deq(&_thread_fd_table[fd]->w_queue)) == NULL) {
} else {
/*
* Set the state of the new owner of
* the thread to running:
*/
_thread_fd_table[fd]->w_owner->state = PS_RUNNING;
/*
* Reset the number of write locks.
* This will be incremented by the
* new owner of the lock when it
* sees that it has the lock.
*/
_thread_fd_table[fd]->w_lockcount = 0;
}
}
}
}
/* Unblock signals again: */
_thread_kern_sig_unblock(status);
/* Nothing to return. */
return;
}
int
_thread_fd_lock(int fd, int lock_type, struct timespec * timeout,
char *fname, int lineno)
{
int ret;
int status;
/* Block signals while the file descriptor lock is tested: */
_thread_kern_sig_block(&status);
/*
* Check that the file descriptor table is initialised for this
* entry:
*/
if ((ret = _thread_fd_table_init(fd)) != 0) {
} else {
/* Check the file descriptor and lock types: */
if (lock_type == FD_READ || lock_type == FD_RDWR) {
/*
* Enter a loop to wait for the file descriptor to be
* locked for read for the current thread:
*/
while (_thread_fd_table[fd]->r_owner != _thread_run) {
/*
* Check if the file descriptor is locked by
* another thread:
*/
if (_thread_fd_table[fd]->r_owner != NULL) {
/*
* Another thread has locked the file
* descriptor for read, so join the
* queue of threads waiting for a
* read lock on this file descriptor:
*/
_thread_queue_enq(&_thread_fd_table[fd]->r_queue, _thread_run);
/*
* Save the file descriptor details
* in the thread structure for the
* running thread:
*/
_thread_run->data.fd.fd = fd;
_thread_run->data.fd.branch = lineno;
_thread_run->data.fd.fname = fname;
/* Set the timeout: */
_thread_kern_set_timeout(timeout);
/*
* Schedule this thread to wait on
* the read lock. It will only be
* woken when it becomes the next in
* the queue and is granted access
* to the lock by the thread
* that is unlocking the file
* descriptor.
*/
_thread_kern_sched_state(PS_FDLR_WAIT, __FILE__, __LINE__);
/*
* Block signals so that the file
* descriptor lock can again be
* tested:
*/
_thread_kern_sig_block(NULL);
} else {
/*
* The running thread now owns the
* read lock on this file descriptor:
*/
_thread_fd_table[fd]->r_owner = _thread_run;
/*
* Reset the number of read locks for
* this file descriptor:
*/
_thread_fd_table[fd]->r_lockcount = 0;
/*
* Save the source file details for
* debugging:
*/
_thread_fd_table[fd]->r_fname = fname;
_thread_fd_table[fd]->r_lineno = lineno;
}
}
/* Increment the read lock count: */
_thread_fd_table[fd]->r_lockcount++;
}
/* Check the file descriptor and lock types: */
if (lock_type == FD_WRITE || lock_type == FD_RDWR) {
/*
* Enter a loop to wait for the file descriptor to be
* locked for write for the current thread:
*/
while (_thread_fd_table[fd]->w_owner != _thread_run) {
/*
* Check if the file descriptor is locked by
* another thread:
*/
if (_thread_fd_table[fd]->w_owner != NULL) {
/*
* Another thread has locked the file
* descriptor for write, so join the
* queue of threads waiting for a
* write lock on this file
* descriptor:
*/
_thread_queue_enq(&_thread_fd_table[fd]->w_queue, _thread_run);
/*
* Save the file descriptor details
* in the thread structure for the
* running thread:
*/
_thread_run->data.fd.fd = fd;
_thread_run->data.fd.branch = lineno;
_thread_run->data.fd.fname = fname;
/* Set the timeout: */
_thread_kern_set_timeout(timeout);
/*
* Schedule this thread to wait on
* the write lock. It will only be
* woken when it becomes the next in
* the queue and is granted access to
* the lock by the thread that is
* unlocking the file descriptor.
*/
_thread_kern_sched_state(PS_FDLW_WAIT, __FILE__, __LINE__);
/*
* Block signals so that the file
* descriptor lock can again be
* tested:
*/
_thread_kern_sig_block(NULL);
} else {
/*
* The running thread now owns the
* write lock on this file
* descriptor:
*/
_thread_fd_table[fd]->w_owner = _thread_run;
/*
* Reset the number of write locks
* for this file descriptor:
*/
_thread_fd_table[fd]->w_lockcount = 0;
/*
* Save the source file details for
* debugging:
*/
_thread_fd_table[fd]->w_fname = fname;
_thread_fd_table[fd]->w_lineno = lineno;
}
}
/* Increment the write lock count: */
_thread_fd_table[fd]->w_lockcount++;
}
}
/* Unblock signals again: */
_thread_kern_sig_unblock(status);
/* Return the completion status: */
return (ret);
}
#endif