0,0 → 1,113 |
/* |
* 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 <typedefs.h> |
#include <mm/slab.h> |
|
/** 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)]; \ |
count_t items; \ |
index_t head; \ |
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; \ |
count_t items; \ |
index_t head; \ |
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, 0) |
|
#endif |