reactos/lib/sdk/crt/conio/kbhit.c

   1 /*
   2  * COPYRIGHT:   See COPYING in the top level directory
   3  * PROJECT:     ReactOS system libraries
   4  * FILE:        lib/msvcrt/conio/kbhit.c
   5  * PURPOSE:     Checks for keyboard hits
   6  * PROGRAMERS:  Ariadne, Russell
   7  * UPDATE HISTORY:
   8  *              28/12/98: Created
   9  *              27/9/08: An almost 100% working version of _kbhit()
  10  */
  11
  12 #include <precomp.h>
  13
  14 static CRITICAL_SECTION CriticalSection;
  15 volatile BOOL CriticalSectionInitialized=FALSE;
  16
  17 /*
  18  * @implemented
  19  */
  20
  21 int _kbhit(void)
  22 {
  23     PINPUT_RECORD InputRecord = NULL;
  24     DWORD NumberRead = 0;
  25     DWORD EventsRead = 0;
  26     DWORD RecordIndex = 0;
  27     DWORD BufferIndex = 0;
  28     HANDLE StdInputHandle = 0;
  29     DWORD ConsoleInputMode = 0;
  30
  31     /* Attempt some thread safety */
  32     if (!CriticalSectionInitialized)
  33     {
  34         InitializeCriticalSectionAndSpinCount(&CriticalSection, 0x80000400);
  35         CriticalSectionInitialized = TRUE;
  36     }
  37
  38     EnterCriticalSection(&CriticalSection);
  39
  40     if (char_avail)
  41     {
  42         LeaveCriticalSection(&CriticalSection);
  43         return 1;
  44     }
  45
  46     StdInputHandle = GetStdHandle(STD_INPUT_HANDLE);
  47
  48     /* Turn off processed input so we get key modifiers as well */
  49     GetConsoleMode(StdInputHandle, &ConsoleInputMode);
  50
  51     SetConsoleMode(StdInputHandle, ConsoleInputMode & ~ENABLE_PROCESSED_INPUT);
  52
  53     /* Start the process */
  54     if (!GetNumberOfConsoleInputEvents(StdInputHandle, &EventsRead))
  55     {
  56         LeaveCriticalSection(&CriticalSection);
  57         return 0;
  58     }
  59
  60     if (!EventsRead)
  61     {
  62         LeaveCriticalSection(&CriticalSection);
  63         return 0;
  64     }
  65
  66     if (!(InputRecord = (PINPUT_RECORD)malloc(EventsRead * sizeof(INPUT_RECORD))))
  67     {
  68         LeaveCriticalSection(&CriticalSection);
  69         return 0;
  70     }
  71
  72     if (!PeekConsoleInput(StdInputHandle, InputRecord, EventsRead, &NumberRead))
  73     {
  74         free(InputRecord);
  75         LeaveCriticalSection(&CriticalSection);
  76         return 0;
  77     }
  78
  79     for (RecordIndex = 0; RecordIndex < NumberRead; RecordIndex++)
  80     {
  81         if (InputRecord[RecordIndex].EventType == KEY_EVENT &&
  82             InputRecord[RecordIndex].Event.KeyEvent.bKeyDown)
  83         {
  84             BufferIndex = 1;
  85             break;
  86         }
  87     }
  88
  89     free(InputRecord);
  90
  91     /* Restore console input mode */
  92     SetConsoleMode(StdInputHandle, ConsoleInputMode);
  93
  94     LeaveCriticalSection(&CriticalSection);
  95
  96     return BufferIndex;
  97 }
  98
  99