experimental threaded libc - kernel only

1 files changed, 124 insertions, 0 deletions

diff --git a/lib/libpthread/uthread/uthread_queue.c b/lib/libpthread/uthread/uthread_queue.c
new file mode 100644
index 00000000000..5225ab8838e
--- /dev/null
+++ b/lib/libpthread/uthread/uthread_queue.c
@@ -0,0 +1,124 @@
+/*
+ * 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 <stdio.h>
+#ifdef _THREAD_SAFE
+#include <pthread.h>
+#include "pthread_private.h"
+
+void
+_thread_queue_init(struct pthread_queue * queue)
+{
+	/* Initialise the pointers in the queue structure: */
+	queue->q_next = NULL;
+	queue->q_last = NULL;
+	queue->q_data = NULL;
+	return;
+}
+
+void
+_thread_queue_enq(struct pthread_queue * queue, struct pthread * thread)
+{
+	if (queue->q_last) {
+		queue->q_last->qnxt = thread;
+	} else {
+		queue->q_next = thread;
+	}
+	queue->q_last = thread;
+	thread->queue = queue;
+	thread->qnxt = NULL;
+	return;
+}
+
+struct pthread *
+_thread_queue_get(struct pthread_queue * queue)
+{
+	/* Return the pointer to the next thread in the queue: */
+	return (queue->q_next);
+}
+
+struct pthread *
+_thread_queue_deq(struct pthread_queue * queue)
+{
+	struct pthread *thread = NULL;
+
+	if (queue->q_next) {
+		thread = queue->q_next;
+		if (!(queue->q_next = queue->q_next->qnxt)) {
+			queue->q_last = NULL;
+		}
+		thread->queue = NULL;
+		thread->qnxt = NULL;
+	}
+	return (thread);
+}
+
+int
+_thread_queue_remove(struct pthread_queue * queue, struct pthread * thread)
+{
+	struct pthread **current = &(queue->q_next);
+	struct pthread *prev = NULL;
+	int             ret = -1;
+
+	while (*current) {
+		if (*current == thread) {
+			if ((*current)->qnxt) {
+				*current = (*current)->qnxt;
+			} else {
+				queue->q_last = prev;
+				*current = NULL;
+			}
+			ret = 0;
+			break;
+		}
+		prev = *current;
+		current = &((*current)->qnxt);
+	}
+	thread->queue = NULL;
+	thread->qnxt = NULL;
+	return (ret);
+}
+
+int
+pthread_llist_remove(struct pthread ** llist, struct pthread * thread)
+{
+	while (*llist) {
+		if (*llist == thread) {
+			*llist = thread->qnxt;
+			return (0);
+		}
+		llist = &(*llist)->qnxt;
+	}
+	return (-1);
+}
+
+#endif