| 0,0 → 1,115 |
|---|
| /* |
| * Copyright (C) 2006 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - 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. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. |
| */ |
| |
| /* |
| * This implementation of FIFO stores values in an array |
| * (static or dynamic). As such, these FIFOs have upper bound |
| * on number of values they can store. Push and pop operations |
| * are done via accessing the array through head and tail indices. |
| * Because of better operation ordering in fifo_pop(), the access |
| * policy for these two indices is to 'increment (mod size of FIFO) |
| * and use'. |
| */ |
| |
| #ifndef __FIFO_H__ |
| #define __FIFO_H__ |
| |
| #include <malloc.h> |
| |
| typedef unsigned long fifo_count_t; |
| typedef unsigned long fifo_index_t; |
| |
| /** Create and initialize static FIFO. |
| * |
| * FIFO is allocated statically. |
| * This macro is suitable for creating smaller FIFOs. |
| * |
| * @param name Name of FIFO. |
| * @param t Type of values stored in FIFO. |
| * @param itms Number of items that can be stored in FIFO. |
| */ |
| #define FIFO_INITIALIZE_STATIC(name, t, itms) \ |
| struct { \ |
| t fifo[(itms)]; \ |
| fifo_count_t items; \ |
| fifo_index_t head; \ |
| fifo_index_t tail; \ |
| } name = { \ |
| .items = (itms), \ |
| .head = 0, \ |
| .tail = 0 \ |
| } |
| |
| /** Create and prepare dynamic FIFO. |
| * |
| * FIFO is allocated dynamically. |
| * This macro is suitable for creating larger FIFOs. |
| * |
| * @param name Name of FIFO. |
| * @param t Type of values stored in FIFO. |
| * @param itms Number of items that can be stored in FIFO. |
| */ |
| #define FIFO_INITIALIZE_DYNAMIC(name, t, itms) \ |
| struct { \ |
| t *fifo; \ |
| fifo_count_t items; \ |
| fifo_index_t head; \ |
| fifo_index_t tail; \ |
| } name = { \ |
| .fifo = NULL, \ |
| .items = (itms), \ |
| .head = 0, \ |
| .tail = 0 \ |
| } |
| |
| /** Pop value from head of FIFO. |
| * |
| * @param name FIFO name. |
| * |
| * @return Leading value in FIFO. |
| */ |
| #define fifo_pop(name) \ |
| name.fifo[name.head = (name.head + 1) < name.items ? (name.head + 1) : 0] |
| |
| /** Push value to tail of FIFO. |
| * |
| * @param name FIFO name. |
| * @param value Value to be appended to FIFO. |
| * |
| */ |
| #define fifo_push(name, value) \ |
| name.fifo[name.tail = (name.tail + 1) < name.items ? (name.tail + 1) : 0] = (value) |
| |
| /** Allocate memory for dynamic FIFO. |
| * |
| * @param name FIFO name. |
| */ |
| #define fifo_create(name) \ |
| name.fifo = malloc(sizeof(*name.fifo) * name.items) |
| |
| #endif |