WebSVN – HelenOS – Diff – /trunk/uspace/kbd/generic/key_buffer.c


/*
 * Copyright (c) 2006 Josef Cejka
 * 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.
 */
 
/** @addtogroup kbdgen
 * @brief   HelenOS generic uspace keyboard handler.
 * @ingroup  kbd
 * @{
 */
/** @file
 */
#include <key_buffer.h>
#include <futex.h>
 
atomic_t keybuffer_futex = FUTEX_INITIALIZER;
 
/** Clear key buffer.
 */
void keybuffer_free(keybuffer_t *keybuffer)
{
    futex_down(&keybuffer_futex);
    keybuffer->head = 0;
    keybuffer->tail = 0;
    keybuffer->items = 0;
    futex_up(&keybuffer_futex);
}
 
/** Key buffer initialization.
 *
 */
void keybuffer_init(keybuffer_t *keybuffer)
{
    keybuffer_free(keybuffer);
}
 
/** Get free space in buffer.
 * This function is useful for processing some scancodes that are translated
 * to more than one character.
 * @return empty buffer space
 */
int keybuffer_available(keybuffer_t *keybuffer)
{
    return KEYBUFFER_SIZE - keybuffer->items;
}
 
/**
 * @return nonzero, if buffer is not empty.
 */
int keybuffer_empty(keybuffer_t *keybuffer)
{
    return (keybuffer->items == 0);
}
 
/** Push key to key buffer.
 * If buffer is full, character is ignored.
 * @param key code of stored key
 */
void keybuffer_push(keybuffer_t *keybuffer, int key)
{
    futex_down(&keybuffer_futex);
    if (keybuffer->items < KEYBUFFER_SIZE) {
        keybuffer->fifo[keybuffer->tail] = key;
        keybuffer->tail = (keybuffer->tail + 1) % KEYBUFFER_SIZE;
        keybuffer->items++;
    }
    futex_up(&keybuffer_futex);
}
 
/** Pop character from buffer.
 * @param c pointer to space where to store character from buffer.
 * @return zero on empty buffer, nonzero else
 */
int keybuffer_pop(keybuffer_t *keybuffer, int *c)
{
    futex_down(&keybuffer_futex);
    if (keybuffer->items > 0) {
        keybuffer->items--;
        *c = (keybuffer->fifo[keybuffer->head]) ;
        keybuffer->head = (keybuffer->head + 1) % KEYBUFFER_SIZE;
        futex_up(&keybuffer_futex);
        return 1;
    }
    futex_up(&keybuffer_futex);
    return 0;
}
 
/**
 * @}
 */
 
 

Rev 1787	Rev 2071
1	/*	1	/*
2	* Copyright (C) 2006 Josef Cejka	2	* Copyright (c) 2006 Josef Cejka
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup kbdgen	29	/** @addtogroup kbdgen
30	* @brief HelenOS generic uspace keyboard handler.	30	* @brief HelenOS generic uspace keyboard handler.
31	* @ingroup kbd	31	* @ingroup kbd
32	* @{	32	* @{
33	*/	33	*/
34	/** @file	34	/** @file
35	*/	35	*/
36	#include <key_buffer.h>	36	#include <key_buffer.h>
37	#include <futex.h>	37	#include <futex.h>
38		38
39	atomic_t keybuffer_futex = FUTEX_INITIALIZER;	39	atomic_t keybuffer_futex = FUTEX_INITIALIZER;
40		40
41	/** Clear key buffer.	41	/** Clear key buffer.
42	*/	42	*/
43	void keybuffer_free(keybuffer_t *keybuffer)	43	void keybuffer_free(keybuffer_t *keybuffer)
44	{	44	{
45	futex_down(&keybuffer_futex);	45	futex_down(&keybuffer_futex);
46	keybuffer->head = 0;	46	keybuffer->head = 0;
47	keybuffer->tail = 0;	47	keybuffer->tail = 0;
48	keybuffer->items = 0;	48	keybuffer->items = 0;
49	futex_up(&keybuffer_futex);	49	futex_up(&keybuffer_futex);
50	}	50	}
51		51
52	/** Key buffer initialization.	52	/** Key buffer initialization.
53	*	53	*
54	*/	54	*/
55	void keybuffer_init(keybuffer_t *keybuffer)	55	void keybuffer_init(keybuffer_t *keybuffer)
56	{	56	{
57	keybuffer_free(keybuffer);	57	keybuffer_free(keybuffer);
58	}	58	}
59		59
60	/** Get free space in buffer.	60	/** Get free space in buffer.
61	* This function is useful for processing some scancodes that are translated	61	* This function is useful for processing some scancodes that are translated
62	* to more than one character.	62	* to more than one character.
63	* @return empty buffer space	63	* @return empty buffer space
64	*/	64	*/
65	int keybuffer_available(keybuffer_t *keybuffer)	65	int keybuffer_available(keybuffer_t *keybuffer)
66	{	66	{
67	return KEYBUFFER_SIZE - keybuffer->items;	67	return KEYBUFFER_SIZE - keybuffer->items;
68	}	68	}
69		69
70	/**	70	/**
71	* @return nonzero, if buffer is not empty.	71	* @return nonzero, if buffer is not empty.
72	*/	72	*/
73	int keybuffer_empty(keybuffer_t *keybuffer)	73	int keybuffer_empty(keybuffer_t *keybuffer)
74	{	74	{
75	return (keybuffer->items == 0);	75	return (keybuffer->items == 0);
76	}	76	}
77		77
78	/** Push key to key buffer.	78	/** Push key to key buffer.
79	* If buffer is full, character is ignored.	79	* If buffer is full, character is ignored.
80	* @param key code of stored key	80	* @param key code of stored key
81	*/	81	*/
82	void keybuffer_push(keybuffer_t *keybuffer, int key)	82	void keybuffer_push(keybuffer_t *keybuffer, int key)
83	{	83	{
84	futex_down(&keybuffer_futex);	84	futex_down(&keybuffer_futex);
85	if (keybuffer->items < KEYBUFFER_SIZE) {	85	if (keybuffer->items < KEYBUFFER_SIZE) {
86	keybuffer->fifo[keybuffer->tail] = key;	86	keybuffer->fifo[keybuffer->tail] = key;
87	keybuffer->tail = (keybuffer->tail + 1) % KEYBUFFER_SIZE;	87	keybuffer->tail = (keybuffer->tail + 1) % KEYBUFFER_SIZE;
88	keybuffer->items++;	88	keybuffer->items++;
89	}	89	}
90	futex_up(&keybuffer_futex);	90	futex_up(&keybuffer_futex);
91	}	91	}
92		92
93	/** Pop character from buffer.	93	/** Pop character from buffer.
94	* @param c pointer to space where to store character from buffer.	94	* @param c pointer to space where to store character from buffer.
95	* @return zero on empty buffer, nonzero else	95	* @return zero on empty buffer, nonzero else
96	*/	96	*/
97	int keybuffer_pop(keybuffer_t keybuffer, int c)	97	int keybuffer_pop(keybuffer_t keybuffer, int c)
98	{	98	{
99	futex_down(&keybuffer_futex);	99	futex_down(&keybuffer_futex);
100	if (keybuffer->items > 0) {	100	if (keybuffer->items > 0) {
101	keybuffer->items--;	101	keybuffer->items--;
102	*c = (keybuffer->fifo[keybuffer->head]) ;	102	*c = (keybuffer->fifo[keybuffer->head]) ;
103	keybuffer->head = (keybuffer->head + 1) % KEYBUFFER_SIZE;	103	keybuffer->head = (keybuffer->head + 1) % KEYBUFFER_SIZE;
104	futex_up(&keybuffer_futex);	104	futex_up(&keybuffer_futex);
105	return 1;	105	return 1;
106	}	106	}
107	futex_up(&keybuffer_futex);	107	futex_up(&keybuffer_futex);
108	return 0;	108	return 0;
109	}	109	}
110		110
111	/**	111	/**
112	* @}	112	* @}
113	*/	113	*/
114		114
115		115

Subversion Repositories HelenOS

(root)/trunk/uspace/kbd/generic/key_buffer.c – Rev 1787 → 2071