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-rw-r--r--lib/libc_r/uthread/uthread_fd.c1041
1 files changed, 1041 insertions, 0 deletions
diff --git a/lib/libc_r/uthread/uthread_fd.c b/lib/libc_r/uthread/uthread_fd.c
new file mode 100644
index 0000000..060515a
--- /dev/null
+++ b/lib/libc_r/uthread/uthread_fd.c
@@ -0,0 +1,1041 @@
+/*
+ * Copyright (c) 1995-1998 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ *
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include "pthread_private.h"
+
+#define FDQ_INSERT(q,p) \
+do { \
+ TAILQ_INSERT_TAIL(q,p,qe); \
+ p->flags |= PTHREAD_FLAGS_IN_FDQ; \
+} while (0)
+
+#define FDQ_REMOVE(q,p) \
+do { \
+ if ((p->flags & PTHREAD_FLAGS_IN_FDQ) != 0) { \
+ TAILQ_REMOVE(q,p,qe); \
+ p->flags &= ~PTHREAD_FLAGS_IN_FDQ; \
+ } \
+} while (0)
+
+
+/* Static variables: */
+static spinlock_t fd_table_lock = _SPINLOCK_INITIALIZER;
+
+/* Prototypes: */
+#ifdef _FDLOCKS_ENABLED
+static inline pthread_t fd_next_reader(int fd);
+static inline pthread_t fd_next_writer(int fd);
+#endif
+
+
+/*
+ * This function *must* return -1 and set the thread specific errno
+ * as a system call. This is because the error return from this
+ * function is propagated directly back from thread-wrapped system
+ * calls.
+ */
+
+int
+_thread_fd_table_init(int fd)
+{
+ int ret = 0;
+ struct fd_table_entry *entry;
+ int saved_errno;
+
+ if (_thread_initial == NULL)
+ _thread_init();
+
+ /* 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) {
+ /* Memory has already been allocated. */
+
+ /* Allocate memory for the file descriptor table entry: */
+ } else if ((entry = (struct fd_table_entry *)
+ malloc(sizeof(struct fd_table_entry))) == NULL) {
+ /* Return an insufficient memory error: */
+ errno = ENOMEM;
+ ret = -1;
+ } else {
+ /* Initialise the file locks: */
+ memset(&entry->lock, 0, sizeof(entry->lock));
+ entry->r_owner = NULL;
+ entry->w_owner = NULL;
+ entry->r_fname = NULL;
+ entry->w_fname = NULL;
+ entry->r_lineno = 0;
+ entry->w_lineno = 0;
+ entry->r_lockcount = 0;
+ entry->w_lockcount = 0;
+
+ /* Initialise the read/write queues: */
+ TAILQ_INIT(&entry->r_queue);
+ TAILQ_INIT(&entry->w_queue);
+
+ /* Get the flags for the file: */
+ if (((fd >= 3) || (_pthread_stdio_flags[fd] == -1)) &&
+ (entry->flags = __sys_fcntl(fd, F_GETFL, 0)) == -1) {
+ ret = -1;
+ }
+ else {
+ /* Check if a stdio descriptor: */
+ if ((fd < 3) && (_pthread_stdio_flags[fd] != -1))
+ /*
+ * Use the stdio flags read by
+ * _pthread_init() to avoid
+ * mistaking the non-blocking
+ * flag that, when set on one
+ * stdio fd, is set on all stdio
+ * fds.
+ */
+ entry->flags = _pthread_stdio_flags[fd];
+
+ /*
+ * Make the file descriptor non-blocking.
+ * This might fail if the device driver does
+ * not support non-blocking calls, or if the
+ * driver is naturally non-blocking.
+ */
+ saved_errno = errno;
+ __sys_fcntl(fd, F_SETFL,
+ entry->flags | O_NONBLOCK);
+ errno = saved_errno;
+
+ /* Lock the file descriptor table: */
+ _SPINLOCK(&fd_table_lock);
+
+ /*
+ * Check if another thread allocated the
+ * file descriptor entry while this thread
+ * was doing the same thing. The table wasn't
+ * kept locked during this operation because
+ * it has the potential to recurse.
+ */
+ if (_thread_fd_table[fd] == NULL) {
+ /* This thread wins: */
+ _thread_fd_table[fd] = entry;
+ entry = NULL;
+ }
+
+ /* Unlock the file descriptor table: */
+ _SPINUNLOCK(&fd_table_lock);
+ }
+
+ /*
+ * Check if another thread initialised the table entry
+ * before this one could:
+ */
+ if (entry != NULL)
+ /*
+ * Throw away the table entry that this thread
+ * prepared. The other thread wins.
+ */
+ free(entry);
+ }
+
+ /* Return the completion status: */
+ return (ret);
+}
+
+#ifdef _FDLOCKS_ENABLED
+void
+_thread_fd_unlock(int fd, int lock_type)
+{
+ struct pthread *curthread = _get_curthread();
+ int ret;
+
+ /*
+ * Check that the file descriptor table is initialised for this
+ * entry:
+ */
+ if ((ret = _thread_fd_table_init(fd)) == 0) {
+ /*
+ * Defer signals to protect the scheduling queues from
+ * access by the signal handler:
+ */
+ _thread_kern_sig_defer();
+
+ /*
+ * Lock the file descriptor table entry to prevent
+ * other threads for clashing with the current
+ * thread's accesses:
+ */
+ _SPINLOCK(&_thread_fd_table[fd]->lock);
+
+ /* Check if the running thread owns the read lock: */
+ if (_thread_fd_table[fd]->r_owner == curthread) {
+ /* 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 = fd_next_reader(fd)) == NULL) {
+ } else {
+ /* Remove this thread from the queue: */
+ FDQ_REMOVE(&_thread_fd_table[fd]->r_queue,
+ _thread_fd_table[fd]->r_owner);
+
+ /*
+ * Set the state of the new owner of
+ * the thread to running:
+ */
+ PTHREAD_NEW_STATE(_thread_fd_table[fd]->r_owner,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 == curthread) {
+ /* 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 = fd_next_writer(fd)) == NULL) {
+ } else {
+ /* Remove this thread from the queue: */
+ FDQ_REMOVE(&_thread_fd_table[fd]->w_queue,
+ _thread_fd_table[fd]->w_owner);
+
+ /*
+ * Set the state of the new owner of
+ * the thread to running:
+ */
+ PTHREAD_NEW_STATE(_thread_fd_table[fd]->w_owner,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;
+ }
+ }
+ }
+
+ /* Unlock the file descriptor table entry: */
+ _SPINUNLOCK(&_thread_fd_table[fd]->lock);
+
+ /*
+ * Undefer and handle pending signals, yielding if
+ * necessary:
+ */
+ _thread_kern_sig_undefer();
+ }
+}
+
+int
+_thread_fd_lock(int fd, int lock_type, struct timespec * timeout)
+{
+ struct pthread *curthread = _get_curthread();
+ int ret;
+
+ /*
+ * Check that the file descriptor table is initialised for this
+ * entry:
+ */
+ if ((ret = _thread_fd_table_init(fd)) == 0) {
+ /* Clear the interrupted flag: */
+ curthread->interrupted = 0;
+
+ /*
+ * Lock the file descriptor table entry to prevent
+ * other threads for clashing with the current
+ * thread's accesses:
+ */
+ _SPINLOCK(&_thread_fd_table[fd]->lock);
+
+ /* Check the file descriptor and lock types: */
+ if (lock_type == FD_READ || lock_type == FD_RDWR) {
+ /*
+ * Wait for the file descriptor to be locked
+ * for read for the current thread:
+ */
+ while ((_thread_fd_table[fd]->r_owner != curthread) &&
+ (curthread->interrupted == 0)) {
+ /*
+ * 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:
+ */
+ FDQ_INSERT(&_thread_fd_table[fd]->r_queue, curthread);
+
+ /*
+ * Save the file descriptor details
+ * in the thread structure for the
+ * running thread:
+ */
+ curthread->data.fd.fd = fd;
+
+ /* Set the timeout: */
+ _thread_kern_set_timeout(timeout);
+
+ /*
+ * Unlock the file descriptor
+ * table entry:
+ */
+ _SPINUNLOCK(&_thread_fd_table[fd]->lock);
+
+ /*
+ * 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__);
+
+ /*
+ * Lock the file descriptor
+ * table entry again:
+ */
+ _SPINLOCK(&_thread_fd_table[fd]->lock);
+
+ if (curthread->interrupted != 0) {
+ FDQ_REMOVE(&_thread_fd_table[fd]->r_queue,
+ curthread);
+ }
+ } else {
+ /*
+ * The running thread now owns the
+ * read lock on this file descriptor:
+ */
+ _thread_fd_table[fd]->r_owner = curthread;
+
+ /*
+ * Reset the number of read locks for
+ * this file descriptor:
+ */
+ _thread_fd_table[fd]->r_lockcount = 0;
+ }
+ }
+
+ if (_thread_fd_table[fd]->r_owner == curthread)
+ /* Increment the read lock count: */
+ _thread_fd_table[fd]->r_lockcount++;
+ }
+
+ /* Check the file descriptor and lock types: */
+ if (curthread->interrupted == 0 &&
+ (lock_type == FD_WRITE || lock_type == FD_RDWR)) {
+ /*
+ * Wait for the file descriptor to be locked
+ * for write for the current thread:
+ */
+ while ((_thread_fd_table[fd]->w_owner != curthread) &&
+ (curthread->interrupted == 0)) {
+ /*
+ * 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:
+ */
+ FDQ_INSERT(&_thread_fd_table[fd]->w_queue, curthread);
+
+ /*
+ * Save the file descriptor details
+ * in the thread structure for the
+ * running thread:
+ */
+ curthread->data.fd.fd = fd;
+
+ /* Set the timeout: */
+ _thread_kern_set_timeout(timeout);
+
+ /*
+ * Unlock the file descriptor
+ * table entry:
+ */
+ _SPINUNLOCK(&_thread_fd_table[fd]->lock);
+
+ /*
+ * 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__);
+
+ /*
+ * Lock the file descriptor
+ * table entry again:
+ */
+ _SPINLOCK(&_thread_fd_table[fd]->lock);
+
+ if (curthread->interrupted != 0) {
+ FDQ_REMOVE(&_thread_fd_table[fd]->w_queue,
+ curthread);
+ }
+ } else {
+ /*
+ * The running thread now owns the
+ * write lock on this file
+ * descriptor:
+ */
+ _thread_fd_table[fd]->w_owner = curthread;
+
+ /*
+ * Reset the number of write locks
+ * for this file descriptor:
+ */
+ _thread_fd_table[fd]->w_lockcount = 0;
+ }
+ }
+
+ if (_thread_fd_table[fd]->w_owner == curthread)
+ /* Increment the write lock count: */
+ _thread_fd_table[fd]->w_lockcount++;
+ }
+
+ /* Unlock the file descriptor table entry: */
+ _SPINUNLOCK(&_thread_fd_table[fd]->lock);
+
+ if (curthread->interrupted != 0) {
+ ret = -1;
+ errno = EINTR;
+ if (curthread->continuation != NULL)
+ curthread->continuation((void *)curthread);
+ }
+ }
+
+ /* Return the completion status: */
+ return (ret);
+}
+
+void
+_thread_fd_unlock_debug(int fd, int lock_type, char *fname, int lineno)
+{
+ struct pthread *curthread = _get_curthread();
+ int ret;
+
+ /*
+ * Check that the file descriptor table is initialised for this
+ * entry:
+ */
+ if ((ret = _thread_fd_table_init(fd)) == 0) {
+ /*
+ * Defer signals to protect the scheduling queues from
+ * access by the signal handler:
+ */
+ _thread_kern_sig_defer();
+
+ /*
+ * Lock the file descriptor table entry to prevent
+ * other threads for clashing with the current
+ * thread's accesses:
+ */
+ _spinlock_debug(&_thread_fd_table[fd]->lock, fname, lineno);
+
+ /* Check if the running thread owns the read lock: */
+ if (_thread_fd_table[fd]->r_owner == curthread) {
+ /* 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 = fd_next_reader(fd)) == NULL) {
+ } else {
+ /* Remove this thread from the queue: */
+ FDQ_REMOVE(&_thread_fd_table[fd]->r_queue,
+ _thread_fd_table[fd]->r_owner);
+
+ /*
+ * Set the state of the new owner of
+ * the thread to running:
+ */
+ PTHREAD_NEW_STATE(_thread_fd_table[fd]->r_owner,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 == curthread) {
+ /* 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 = fd_next_writer(fd)) == NULL) {
+ } else {
+ /* Remove this thread from the queue: */
+ FDQ_REMOVE(&_thread_fd_table[fd]->w_queue,
+ _thread_fd_table[fd]->w_owner);
+
+ /*
+ * Set the state of the new owner of
+ * the thread to running:
+ */
+ PTHREAD_NEW_STATE(_thread_fd_table[fd]->w_owner,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;
+ }
+ }
+ }
+
+ /* Unlock the file descriptor table entry: */
+ _SPINUNLOCK(&_thread_fd_table[fd]->lock);
+
+ /*
+ * Undefer and handle pending signals, yielding if
+ * necessary.
+ */
+ _thread_kern_sig_undefer();
+ }
+}
+
+int
+_thread_fd_lock_debug(int fd, int lock_type, struct timespec * timeout,
+ char *fname, int lineno)
+{
+ struct pthread *curthread = _get_curthread();
+ int ret;
+
+ /*
+ * Check that the file descriptor table is initialised for this
+ * entry:
+ */
+ if ((ret = _thread_fd_table_init(fd)) == 0) {
+ /* Clear the interrupted flag: */
+ curthread->interrupted = 0;
+
+ /*
+ * Lock the file descriptor table entry to prevent
+ * other threads for clashing with the current
+ * thread's accesses:
+ */
+ _spinlock_debug(&_thread_fd_table[fd]->lock, fname, lineno);
+
+ /* Check the file descriptor and lock types: */
+ if (lock_type == FD_READ || lock_type == FD_RDWR) {
+ /*
+ * Wait for the file descriptor to be locked
+ * for read for the current thread:
+ */
+ while ((_thread_fd_table[fd]->r_owner != curthread) &&
+ (curthread->interrupted == 0)) {
+ /*
+ * 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:
+ */
+ FDQ_INSERT(&_thread_fd_table[fd]->r_queue, curthread);
+
+ /*
+ * Save the file descriptor details
+ * in the thread structure for the
+ * running thread:
+ */
+ curthread->data.fd.fd = fd;
+ curthread->data.fd.branch = lineno;
+ curthread->data.fd.fname = fname;
+
+ /* Set the timeout: */
+ _thread_kern_set_timeout(timeout);
+
+ /*
+ * Unlock the file descriptor
+ * table entry:
+ */
+ _SPINUNLOCK(&_thread_fd_table[fd]->lock);
+
+ /*
+ * 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__);
+
+ /*
+ * Lock the file descriptor
+ * table entry again:
+ */
+ _SPINLOCK(&_thread_fd_table[fd]->lock);
+
+ if (curthread->interrupted != 0) {
+ FDQ_REMOVE(&_thread_fd_table[fd]->r_queue,
+ curthread);
+ }
+ } else {
+ /*
+ * The running thread now owns the
+ * read lock on this file descriptor:
+ */
+ _thread_fd_table[fd]->r_owner = curthread;
+
+ /*
+ * 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;
+ }
+ }
+
+ if (_thread_fd_table[fd]->r_owner == curthread)
+ /* Increment the read lock count: */
+ _thread_fd_table[fd]->r_lockcount++;
+ }
+
+ /* Check the file descriptor and lock types: */
+ if (curthread->interrupted == 0 &&
+ (lock_type == FD_WRITE || lock_type == FD_RDWR)) {
+ /*
+ * Wait for the file descriptor to be locked
+ * for write for the current thread:
+ */
+ while ((_thread_fd_table[fd]->w_owner != curthread) &&
+ (curthread->interrupted == 0)) {
+ /*
+ * 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:
+ */
+ FDQ_INSERT(&_thread_fd_table[fd]->w_queue, curthread);
+
+ /*
+ * Save the file descriptor details
+ * in the thread structure for the
+ * running thread:
+ */
+ curthread->data.fd.fd = fd;
+ curthread->data.fd.branch = lineno;
+ curthread->data.fd.fname = fname;
+
+ /* Set the timeout: */
+ _thread_kern_set_timeout(timeout);
+
+ /*
+ * Unlock the file descriptor
+ * table entry:
+ */
+ _SPINUNLOCK(&_thread_fd_table[fd]->lock);
+
+ /*
+ * 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__);
+
+ /*
+ * Lock the file descriptor
+ * table entry again:
+ */
+ _SPINLOCK(&_thread_fd_table[fd]->lock);
+
+ if (curthread->interrupted != 0) {
+ FDQ_REMOVE(&_thread_fd_table[fd]->w_queue,
+ curthread);
+ }
+ } else {
+ /*
+ * The running thread now owns the
+ * write lock on this file
+ * descriptor:
+ */
+ _thread_fd_table[fd]->w_owner = curthread;
+
+ /*
+ * 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;
+ }
+ }
+
+ if (_thread_fd_table[fd]->w_owner == curthread)
+ /* Increment the write lock count: */
+ _thread_fd_table[fd]->w_lockcount++;
+ }
+
+ /* Unlock the file descriptor table entry: */
+ _SPINUNLOCK(&_thread_fd_table[fd]->lock);
+
+ if (curthread->interrupted != 0) {
+ ret = -1;
+ errno = EINTR;
+ if (curthread->continuation != NULL)
+ curthread->continuation((void *)curthread);
+ }
+ }
+
+ /* Return the completion status: */
+ return (ret);
+}
+
+void
+_thread_fd_unlock_owned(pthread_t pthread)
+{
+ int fd;
+
+ for (fd = 0; fd < _thread_dtablesize; fd++) {
+ if ((_thread_fd_table[fd] != NULL) &&
+ ((_thread_fd_table[fd]->r_owner == pthread) ||
+ (_thread_fd_table[fd]->w_owner == pthread))) {
+ /*
+ * Defer signals to protect the scheduling queues
+ * from access by the signal handler:
+ */
+ _thread_kern_sig_defer();
+
+ /*
+ * Lock the file descriptor table entry to prevent
+ * other threads for clashing with the current
+ * thread's accesses:
+ */
+ _SPINLOCK(&_thread_fd_table[fd]->lock);
+
+ /* Check if the thread owns the read lock: */
+ if (_thread_fd_table[fd]->r_owner == pthread) {
+ /* Clear the read lock count: */
+ _thread_fd_table[fd]->r_lockcount = 0;
+
+ /*
+ * Get the next thread in the queue for a
+ * read lock on this file descriptor:
+ */
+ if ((_thread_fd_table[fd]->r_owner = fd_next_reader(fd)) != NULL) {
+ /* Remove this thread from the queue: */
+ FDQ_REMOVE(&_thread_fd_table[fd]->r_queue,
+ _thread_fd_table[fd]->r_owner);
+
+ /*
+ * Set the state of the new owner of
+ * the thread to running:
+ */
+ PTHREAD_NEW_STATE(_thread_fd_table[fd]->r_owner,PS_RUNNING);
+ }
+ }
+
+ /* Check if the thread owns the write lock: */
+ if (_thread_fd_table[fd]->w_owner == pthread) {
+ /* Clear the write lock count: */
+ _thread_fd_table[fd]->w_lockcount = 0;
+
+ /*
+ * Get the next thread in the queue for a
+ * write lock on this file descriptor:
+ */
+ if ((_thread_fd_table[fd]->w_owner = fd_next_writer(fd)) != NULL) {
+ /* Remove this thread from the queue: */
+ FDQ_REMOVE(&_thread_fd_table[fd]->w_queue,
+ _thread_fd_table[fd]->w_owner);
+
+ /*
+ * Set the state of the new owner of
+ * the thread to running:
+ */
+ PTHREAD_NEW_STATE(_thread_fd_table[fd]->w_owner,PS_RUNNING);
+
+ }
+ }
+
+ /* Unlock the file descriptor table entry: */
+ _SPINUNLOCK(&_thread_fd_table[fd]->lock);
+
+ /*
+ * Undefer and handle pending signals, yielding if
+ * necessary.
+ */
+ _thread_kern_sig_undefer();
+ }
+ }
+}
+
+void
+_fd_lock_backout(pthread_t pthread)
+{
+ int fd;
+
+ /*
+ * Defer signals to protect the scheduling queues
+ * from access by the signal handler:
+ */
+ _thread_kern_sig_defer();
+
+ switch (pthread->state) {
+
+ case PS_FDLR_WAIT:
+ fd = pthread->data.fd.fd;
+
+ /*
+ * Lock the file descriptor table entry to prevent
+ * other threads for clashing with the current
+ * thread's accesses:
+ */
+ _SPINLOCK(&_thread_fd_table[fd]->lock);
+
+ /* Remove the thread from the waiting queue: */
+ FDQ_REMOVE(&_thread_fd_table[fd]->r_queue, pthread);
+ break;
+
+ case PS_FDLW_WAIT:
+ fd = pthread->data.fd.fd;
+
+ /*
+ * Lock the file descriptor table entry to prevent
+ * other threads from clashing with the current
+ * thread's accesses:
+ */
+ _SPINLOCK(&_thread_fd_table[fd]->lock);
+
+ /* Remove the thread from the waiting queue: */
+ FDQ_REMOVE(&_thread_fd_table[fd]->w_queue, pthread);
+ break;
+
+ default:
+ break;
+ }
+
+ /*
+ * Undefer and handle pending signals, yielding if
+ * necessary.
+ */
+ _thread_kern_sig_undefer();
+}
+
+static inline pthread_t
+fd_next_reader(int fd)
+{
+ pthread_t pthread;
+
+ while (((pthread = TAILQ_FIRST(&_thread_fd_table[fd]->r_queue)) != NULL) &&
+ (pthread->interrupted != 0)) {
+ /*
+ * This thread has either been interrupted by a signal or
+ * it has been canceled. Remove it from the queue.
+ */
+ FDQ_REMOVE(&_thread_fd_table[fd]->r_queue, pthread);
+ }
+
+ return (pthread);
+}
+
+static inline pthread_t
+fd_next_writer(int fd)
+{
+ pthread_t pthread;
+
+ while (((pthread = TAILQ_FIRST(&_thread_fd_table[fd]->w_queue)) != NULL) &&
+ (pthread->interrupted != 0)) {
+ /*
+ * This thread has either been interrupted by a signal or
+ * it has been canceled. Remove it from the queue.
+ */
+ FDQ_REMOVE(&_thread_fd_table[fd]->w_queue, pthread);
+ }
+
+ return (pthread);
+}
+
+#else
+
+void
+_thread_fd_unlock(int fd, int lock_type)
+{
+}
+
+int
+_thread_fd_lock(int fd, int lock_type, struct timespec * timeout)
+{
+ /*
+ * Insure that the file descriptor table is initialized for this
+ * entry:
+ */
+ return (_thread_fd_table_init(fd));
+}
+
+void
+_thread_fd_unlock_debug(int fd, int lock_type, char *fname, int lineno)
+{
+}
+
+int
+_thread_fd_lock_debug(int fd, int lock_type, struct timespec * timeout,
+ char *fname, int lineno)
+{
+ /*
+ * Insure that the file descriptor table is initialized for this
+ * entry:
+ */
+ return (_thread_fd_table_init(fd));
+}
+
+void
+_thread_fd_unlock_owned(pthread_t pthread)
+{
+}
+
+void
+_fd_lock_backout(pthread_t pthread)
+{
+}
+
+#endif
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