| 0,0 → 1,114 |
|---|
| /* |
| * 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; |
| } |
| |
| /** |
| * @} |
| */ |
| |