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, char 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, char *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 1451	Rev 1476
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>
-		31
-		32	atomic_t keybuffer_futex = FUTEX_INITIALIZER;
30		33
31	/** Clear key buffer.	34	/** Clear key buffer.
32	*/	35	*/
33	void keybuffer_free(keybuffer_t *keybuffer)	36	void keybuffer_free(keybuffer_t *keybuffer)
34	{	37	{
35		-
-		38	futex_down(&keybuffer_futex);
-		39	keybuffer->head = 0;
-		40	keybuffer->tail = 0;
36	keybuffer->items = 0;	41	keybuffer->items = 0;
37	keybuffer->head = keybuffer->tail = keybuffer->items = 0;	42	futex_up(&keybuffer_futex);
38	}	43	}
39		44
40	/** Key buffer initialization.	45	/** Key buffer initialization.
41	*	46	*
42	*/	47	*/
43	void keybuffer_init(keybuffer_t *keybuffer)	48	void keybuffer_init(keybuffer_t *keybuffer)
44	{	49	{
45	keybuffer_free(keybuffer);	50	keybuffer_free(keybuffer);
46	}	51	}
47		52
48	/** Get free space in buffer.	53	/** Get free space in buffer.
49	* This function is useful for processing some scancodes that are translated	54	* This function is useful for processing some scancodes that are translated
50	* to more than one character.	55	* to more than one character.
51	* @return empty buffer space	56	* @return empty buffer space
52	*/	57	*/
53	int keybuffer_available(keybuffer_t *keybuffer)	58	int keybuffer_available(keybuffer_t *keybuffer)
54	{	59	{
55	return KEYBUFFER_SIZE - keybuffer->items;	60	return KEYBUFFER_SIZE - keybuffer->items;
56	}	61	}
57		62
58	/**	63	/**
59	* @return nonzero, if buffer is not empty.	64	* @return nonzero, if buffer is not empty.
60	*/	65	*/
61	int keybuffer_empty(keybuffer_t *keybuffer)	66	int keybuffer_empty(keybuffer_t *keybuffer)
62	{	67	{
63	return (keybuffer->items == 0);	68	return (keybuffer->items == 0);
64	}	69	}
65		70
66	/** Push key to key buffer.	71	/** Push key to key buffer.
67	* If buffer is full, character is ignored.	72	* If buffer is full, character is ignored.
68	* @param key code of stored key	73	* @param key code of stored key
69	*/	74	*/
70	void keybuffer_push(keybuffer_t *keybuffer, char key)	75	void keybuffer_push(keybuffer_t *keybuffer, char key)
71	{	76	{
-		77	futex_down(&keybuffer_futex);
72	if (keybuffer->items < KEYBUFFER_SIZE) {	78	if (keybuffer->items < KEYBUFFER_SIZE) {
-		79	keybuffer->fifo[keybuffer->tail] = key;
73	keybuffer->fifo[keybuffer->tail = (keybuffer->tail + 1) < keybuffer->items ? (keybuffer->tail + 1) : 0] = (key);	80	keybuffer->tail = (keybuffer->tail + 1) % KEYBUFFER_SIZE;
74	keybuffer->items++;	81	keybuffer->items++;
75	}	82	}
-		83	futex_up(&keybuffer_futex);
76	}	84	}
77		85
78	/** Pop character from buffer.	86	/** Pop character from buffer.
79	* @param c pointer to space where to store character from buffer.	87	* @param c pointer to space where to store character from buffer.
80	* @return zero on empty buffer, nonzero else	88	* @return zero on empty buffer, nonzero else
81	*/	89	*/
82	int keybuffer_pop(keybuffer_t keybuffer, char c)	90	int keybuffer_pop(keybuffer_t keybuffer, char c)
83	{	91	{
-		92	futex_down(&keybuffer_futex);
84	if (keybuffer->items > 0) {	93	if (keybuffer->items > 0) {
85	keybuffer->items--;	94	keybuffer->items--;
-		95	*c = keybuffer->fifo[keybuffer->head];
86	*c = keybuffer->fifo[keybuffer->head = (keybuffer->head + 1) < keybuffer->items ? (keybuffer->head + 1) : 0];	96	keybuffer->head = (keybuffer->head + 1) % KEYBUFFER_SIZE;
-		97	futex_up(&keybuffer_futex);
87	return 1;	98	return 1;
88	}	99	}
-		100	futex_up(&keybuffer_futex);
89	return 0;	101	return 0;
90	}	102	}
91		103
92		104
93		105

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/kbd/generic/key_buffer.c – Rev 1451 → 1476