janus: reducing memory allocating using ring buffer

src/libs/ring.c

@@ -0,0 +1,86 @@
+/*****************************************************************************
+#                                                                            #
+#    uStreamer - Lightweight and fast MJPEG-HTTP streamer.                   #
+#                                                                            #
+#    Copyright (C) 2018-2023  Maxim Devaev <mdevaev@gmail.com>               #
+#                                                                            #
+#    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 3 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, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+*****************************************************************************/
+
+
+#include <assert.h>
+
+#include "ring.h"
+
+#include "types.h"
+#include "tools.h"
+#include "queue.h"
+
+
+int _acquire(us_ring_s *ring, us_queue_s *queue, ldf timeout);
+void _release(us_ring_s *ring, us_queue_s *queue, uint index);
+
+
+us_ring_s *us_ring_init(uint capacity) {
+	us_ring_s *ring;
+	US_CALLOC(ring, 1);
+	US_CALLOC(ring->items, capacity);
+	US_CALLOC(ring->places, capacity);
+	ring->capacity = capacity;
+	ring->producer = us_queue_init(capacity);
+	ring->consumer = us_queue_init(capacity);
+	for (uint index = 0; index < capacity; ++index) {
+		ring->places[index] = index; // XXX: Just to avoid casting between pointer and uint
+		assert(!us_queue_put(ring->producer, (void*)(ring->places + index), 0));
+	}
+	return ring;
+}
+
+void us_ring_destroy(us_ring_s *ring) {
+	us_queue_destroy(ring->consumer);
+	us_queue_destroy(ring->producer);
+	free(ring->places);
+	free(ring->items);
+	free(ring);
+}
+
+int us_ring_producer_acquire(us_ring_s *ring, ldf timeout) {
+	return _acquire(ring, ring->producer, timeout);
+}
+
+void us_ring_producer_release(us_ring_s *ring, uint index) {
+	_release(ring, ring->consumer, index);
+}
+
+int us_ring_consumer_acquire(us_ring_s *ring, ldf timeout) {
+	return _acquire(ring, ring->consumer, timeout);
+}
+
+void us_ring_consumer_release(us_ring_s *ring, uint index) {
+	_release(ring, ring->producer, index);
+}
+
+int _acquire(us_ring_s *ring, us_queue_s *queue, ldf timeout) {
+	(void)ring;
+	uint *place;
+	if (us_queue_get(queue, (void**)&place, timeout) < 0) {
+		return -1;
+	}
+	return *place;
+}
+
+void _release(us_ring_s *ring, us_queue_s *queue, uint index) {
+	assert(!us_queue_put(queue, (void*)(ring->places + index), 0));
+}

src/libs/ring.h

@@ -0,0 +1,63 @@
+/*****************************************************************************
+#                                                                            #
+#    uStreamer - Lightweight and fast MJPEG-HTTP streamer.                   #
+#                                                                            #
+#    Copyright (C) 2018-2023  Maxim Devaev <mdevaev@gmail.com>               #
+#                                                                            #
+#    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 3 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, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+*****************************************************************************/
+
+
+#pragma once
+
+
+#include "types.h"
+#include "queue.h"
+
+
+typedef struct {
+	uz			capacity;
+	void		**items;
+	uint		*places;
+	us_queue_s	*producer;
+	us_queue_s	*consumer;
+} us_ring_s;
+
+
+#define US_RING_INIT_WITH_ITEMS(x_ring, x_capacity, x_init_item) { \
+		(x_ring) = us_ring_init(x_capacity); \
+		for (uz m_index = 0; m_index < (x_ring)->capacity; ++m_index) { \
+			(x_ring)->items[m_index] = x_init_item(); \
+		} \
+	}
+
+#define US_RING_DELETE_WITH_ITEMS(x_ring, x_destroy_item) { \
+		if (x_ring) { \
+			for (uz m_index = 0; m_index < (x_ring)->capacity; ++m_index) { \
+				x_destroy_item((x_ring)->items[m_index]); \
+			} \
+			us_ring_destroy(x_ring); \
+		} \
+	}
+
+
+us_ring_s *us_ring_init(uint capacity);
+void us_ring_destroy(us_ring_s *ring);
+
+int us_ring_producer_acquire(us_ring_s *ring, ldf timeout);
+void us_ring_producer_release(us_ring_s *ring, uint index);
+
+int us_ring_consumer_acquire(us_ring_s *ring, ldf timeout);
+void us_ring_consumer_release(us_ring_s *ring, uint index);