1 files changed, 118 insertions, 0 deletions
diff --git a/src/write_queue.c b/src/write_queue.c
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+/* Generic write queue implementation */
+/*
+ * (C) 2010 by Holger Hans Peter Freyther
+ * (C) 2010 by On-Waves
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <osmocom/core/write_queue.h>
+
+/*! \addtogroup write_queue
+ *  @{
+ */
+
+/*! \file write_queue.c */
+
+/*! \brief Select loop function for write queue handling
+ *  \param[in] fd osmocom file descriptor
+ *  \param[in] what bit-mask of events that have happened
+ *
+ * This function is provided so that it can be registered with the
+ * select loop abstraction code (\ref osmo_fd::cb).
+ */
+int osmo_wqueue_bfd_cb(struct osmo_fd *fd, unsigned int what)
+{
+	struct osmo_wqueue *queue;
+
+	queue = container_of(fd, struct osmo_wqueue, bfd);
+
+	if (what & BSC_FD_READ)
+		queue->read_cb(fd);
+
+	if (what & BSC_FD_EXCEPT)
+		queue->except_cb(fd);
+
+	if (what & BSC_FD_WRITE) {
+		struct msgb *msg;
+
+		fd->when &= ~BSC_FD_WRITE;
+
+		/* the queue might have been emptied */
+		if (!llist_empty(&queue->msg_queue)) {
+			--queue->current_length;
+
+			msg = msgb_dequeue(&queue->msg_queue);
+			queue->write_cb(fd, msg);
+			msgb_free(msg);
+
+			if (!llist_empty(&queue->msg_queue))
+				fd->when |= BSC_FD_WRITE;
+		}
+	}
+
+	return 0;
+}
+
+/*! \brief Initialize a \ref osmo_wqueue structure
+ *  \param[in] queue Write queue to operate on
+ *  \param[in] max_length Maximum length of write queue
+ */
+void osmo_wqueue_init(struct osmo_wqueue *queue, int max_length)
+{
+	queue->max_length = max_length;
+	queue->current_length = 0;
+	queue->read_cb = NULL;
+	queue->write_cb = NULL;
+	queue->bfd.cb = osmo_wqueue_bfd_cb;
+	INIT_LLIST_HEAD(&queue->msg_queue);
+}
+
+/*! \brief Enqueue a new \ref msgb into a write queue
+ *  \param[in] queue Write queue to be used
+ *  \param[in] data to-be-enqueued message buffer
+ */
+int osmo_wqueue_enqueue(struct osmo_wqueue *queue, struct msgb *data)
+{
+//	if (queue->current_length + 1 >= queue->max_length)
+//		LOGP(DMSC, LOGL_ERROR, "The queue is full. Dropping not yet implemented.\n");
+
+	++queue->current_length;
+	msgb_enqueue(&queue->msg_queue, data);
+	queue->bfd.when |= BSC_FD_WRITE;
+
+	return 0;
+}
+
+/*! \brief Clear a \ref osmo_wqueue
+ *  \param[in] queue Write queue to be cleared
+ *
+ * This function will clear (remove/release) all messages in it.
+ */
+void osmo_wqueue_clear(struct osmo_wqueue *queue)
+{
+	while (!llist_empty(&queue->msg_queue)) {
+		struct msgb *msg = msgb_dequeue(&queue->msg_queue);
+		msgb_free(msg);
+	}
+
+	queue->current_length = 0;
+	queue->bfd.when &= ~BSC_FD_WRITE;
+}
+
+/*! @} */