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  1. /*
  2.  * Copyright (c) 2006 Josef Cejka
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  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
  15.  *   derived from this software without specific prior written permission.
  16.  *
  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
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  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
  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
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup kbdgen
  30.  * @brief HelenOS generic uspace keyboard handler.
  31.  * @ingroup kbd
  32.  * @{
  33.  */
  34. /** @file
  35.  */
  36.  
  37. #include <keybuffer.h>
  38. #include <futex.h>
  39.  
  40. atomic_t keybuffer_futex = FUTEX_INITIALIZER;
  41.  
  42. /** Clear key buffer.
  43.  */
  44. void keybuffer_free(keybuffer_t *keybuffer)
  45. {
  46.     futex_down(&keybuffer_futex);
  47.     keybuffer->head = 0;
  48.     keybuffer->tail = 0;
  49.     keybuffer->items = 0;
  50.     futex_up(&keybuffer_futex);
  51. }
  52.  
  53. /** Key buffer initialization.
  54.  *
  55.  */
  56. void keybuffer_init(keybuffer_t *keybuffer)
  57. {
  58.     keybuffer_free(keybuffer);
  59. }
  60.  
  61. /** Get free space in buffer.
  62.  *
  63.  * This function is useful for processing some scancodes that are translated
  64.  * to more than one character.
  65.  *
  66.  * @return empty buffer space
  67.  *
  68.  */
  69. size_t keybuffer_available(keybuffer_t *keybuffer)
  70. {
  71.     return KEYBUFFER_SIZE - keybuffer->items;
  72. }
  73.  
  74. /**
  75.  *
  76.  * @return nonzero, if buffer is not empty.
  77.  *
  78.  */
  79. bool keybuffer_empty(keybuffer_t *keybuffer)
  80. {
  81.     return (keybuffer->items == 0);
  82. }
  83.  
  84. /** Push key event to key buffer.
  85.  *
  86.  * If the buffer is full, the event is ignored.
  87.  *
  88.  * @param keybuffer The keybuffer.
  89.  * @param ev        The event to push.
  90.  *
  91.  */
  92. void keybuffer_push(keybuffer_t *keybuffer, const console_event_t *ev)
  93. {
  94.     futex_down(&keybuffer_futex);
  95.    
  96.     if (keybuffer->items < KEYBUFFER_SIZE) {
  97.         keybuffer->fifo[keybuffer->tail] = *ev;
  98.         keybuffer->tail = (keybuffer->tail + 1) % KEYBUFFER_SIZE;
  99.         keybuffer->items++;
  100.     }
  101.    
  102.     futex_up(&keybuffer_futex);
  103. }
  104.  
  105. /** Pop event from buffer.
  106.  *
  107.  * @param edst Pointer to where the event should be saved.
  108.  *
  109.  * @return True if an event was popped.
  110.  *
  111.  */
  112. bool keybuffer_pop(keybuffer_t *keybuffer, console_event_t *edst)
  113. {
  114.     futex_down(&keybuffer_futex);
  115.    
  116.     if (keybuffer->items > 0) {
  117.         keybuffer->items--;
  118.         *edst = (keybuffer->fifo[keybuffer->head]);
  119.         keybuffer->head = (keybuffer->head + 1) % KEYBUFFER_SIZE;
  120.         futex_up(&keybuffer_futex);
  121.        
  122.         return true;
  123.     }
  124.    
  125.     futex_up(&keybuffer_futex);
  126.    
  127.     return false;
  128. }
  129.  
  130. /**
  131.  * @}
  132.  */
  133.