WebSVN – HelenOS-historic – Diff – /uspace/trunk/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.
 */
 
#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 1476	Rev 1560
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	#include <key_buffer.h>	29	#include <key_buffer.h>
30	#include <futex.h>	30	#include <futex.h>
31		31
32	atomic_t keybuffer_futex = FUTEX_INITIALIZER;	32	atomic_t keybuffer_futex = FUTEX_INITIALIZER;
33		33
34	/** Clear key buffer.	34	/** Clear key buffer.
35	*/	35	*/
36	void keybuffer_free(keybuffer_t *keybuffer)	36	void keybuffer_free(keybuffer_t *keybuffer)
37	{	37	{
38	futex_down(&keybuffer_futex);	38	futex_down(&keybuffer_futex);
39	keybuffer->head = 0;	39	keybuffer->head = 0;
40	keybuffer->tail = 0;	40	keybuffer->tail = 0;
41	keybuffer->items = 0;	41	keybuffer->items = 0;
42	futex_up(&keybuffer_futex);	42	futex_up(&keybuffer_futex);
43	}	43	}
44		44
45	/** Key buffer initialization.	45	/** Key buffer initialization.
46	*	46	*
47	*/	47	*/
48	void keybuffer_init(keybuffer_t *keybuffer)	48	void keybuffer_init(keybuffer_t *keybuffer)
49	{	49	{
50	keybuffer_free(keybuffer);	50	keybuffer_free(keybuffer);
51	}	51	}
52		52
53	/** Get free space in buffer.	53	/** Get free space in buffer.
54	* This function is useful for processing some scancodes that are translated	54	* This function is useful for processing some scancodes that are translated
55	* to more than one character.	55	* to more than one character.
56	* @return empty buffer space	56	* @return empty buffer space
57	*/	57	*/
58	int keybuffer_available(keybuffer_t *keybuffer)	58	int keybuffer_available(keybuffer_t *keybuffer)
59	{	59	{
60	return KEYBUFFER_SIZE - keybuffer->items;	60	return KEYBUFFER_SIZE - keybuffer->items;
61	}	61	}
62		62
63	/**	63	/**
64	* @return nonzero, if buffer is not empty.	64	* @return nonzero, if buffer is not empty.
65	*/	65	*/
66	int keybuffer_empty(keybuffer_t *keybuffer)	66	int keybuffer_empty(keybuffer_t *keybuffer)
67	{	67	{
68	return (keybuffer->items == 0);	68	return (keybuffer->items == 0);
69	}	69	}
70		70
71	/** Push key to key buffer.	71	/** Push key to key buffer.
72	* If buffer is full, character is ignored.	72	* If buffer is full, character is ignored.
73	* @param key code of stored key	73	* @param key code of stored key
74	*/	74	*/
75	void keybuffer_push(keybuffer_t *keybuffer, char key)	75	void keybuffer_push(keybuffer_t *keybuffer, int key)
76	{	76	{
77	futex_down(&keybuffer_futex);	77	futex_down(&keybuffer_futex);
78	if (keybuffer->items < KEYBUFFER_SIZE) {	78	if (keybuffer->items < KEYBUFFER_SIZE) {
79	keybuffer->fifo[keybuffer->tail] = key;	79	keybuffer->fifo[keybuffer->tail] = key;
80	keybuffer->tail = (keybuffer->tail + 1) % KEYBUFFER_SIZE;	80	keybuffer->tail = (keybuffer->tail + 1) % KEYBUFFER_SIZE;
81	keybuffer->items++;	81	keybuffer->items++;
82	}	82	}
83	futex_up(&keybuffer_futex);	83	futex_up(&keybuffer_futex);
84	}	84	}
85		85
86	/** Pop character from buffer.	86	/** Pop character from buffer.
87	* @param c pointer to space where to store character from buffer.	87	* @param c pointer to space where to store character from buffer.
88	* @return zero on empty buffer, nonzero else	88	* @return zero on empty buffer, nonzero else
89	*/	89	*/
90	int keybuffer_pop(keybuffer_t keybuffer, char c)	90	int keybuffer_pop(keybuffer_t keybuffer, int c)
91	{	91	{
92	futex_down(&keybuffer_futex);	92	futex_down(&keybuffer_futex);
93	if (keybuffer->items > 0) {	93	if (keybuffer->items > 0) {
94	keybuffer->items--;	94	keybuffer->items--;
95	*c = keybuffer->fifo[keybuffer->head];	95	*c = (keybuffer->fifo[keybuffer->head]) ;
96	keybuffer->head = (keybuffer->head + 1) % KEYBUFFER_SIZE;	96	keybuffer->head = (keybuffer->head + 1) % KEYBUFFER_SIZE;
97	futex_up(&keybuffer_futex);	97	futex_up(&keybuffer_futex);
98	return 1;	98	return 1;
99	}	99	}
100	futex_up(&keybuffer_futex);	100	futex_up(&keybuffer_futex);
101	return 0;	101	return 0;
102	}	102	}
103		103
104		104
105		105

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/kbd/generic/key_buffer.c – Rev 1476 → 1560