windows/timer.c

   1 /*
   2  * Timer functions
   3  *
   4  * Copyright 1993 Alexandre Julliard
   5  */
   6
   7 static char Copyright[] = "Copyright  Alexandre Julliard, 1993";
   8
   9 #include "windows.h"
  10 #include "message.h"
  11
  12
  13 typedef struct tagTIMER
  14 {
  15     HWND             hwnd;
  16     WORD             msg;  /* WM_TIMER or WM_SYSTIMER */
  17     WORD             id;
  18     WORD             timeout;
  19     struct tagTIMER *next;
  20     DWORD            expires;
  21     FARPROC          proc;
  22 } TIMER;
  23
  24 #define NB_TIMERS            34
  25 #define NB_RESERVED_TIMERS    2  /* for SetSystemTimer */
  26
  27 static TIMER TimersArray[NB_TIMERS];
  28
  29 static TIMER * pNextTimer = NULL;  /* Next timer to expire */
  30
  31
  32 /***********************************************************************
  33  *           TIMER_InsertTimer
  34  *
  35  * Insert the timer at its place in the chain.
  36  */
  37 static void TIMER_InsertTimer( TIMER * pTimer )
  38 {
  39     if (!pNextTimer || (pTimer->expires < pNextTimer->expires))
  40     {
  41         pTimer->next = pNextTimer;
  42         pNextTimer = pTimer;
  43     }
  44     else
  45     {
  46         TIMER * ptr = pNextTimer;
  47         while (ptr->next && (pTimer->expires >= ptr->next->expires))
  48             ptr = ptr->next;
  49         pTimer->next = ptr;
  50         ptr->next = pTimer;
  51     }
  52 }
  53
  54
  55 /***********************************************************************
  56  *           TIMER_RemoveTimer
  57  *
  58  * Remove the timer from the chain.
  59  */
  60 static void TIMER_RemoveTimer( TIMER * pTimer )
  61 {
  62     if (pTimer == pNextTimer) pNextTimer = pTimer->next;
  63     else
  64     {
  65         TIMER * ptr = pNextTimer;
  66         while (ptr && (ptr->next != pTimer)) ptr = ptr->next;
  67         if (ptr) ptr->next = pTimer->next;
  68     }
  69     pTimer->next = NULL;
  70 }
  71
  72
  73 /***********************************************************************
  74  *           TIMER_NextExpire
  75  *
  76  * Return time until next timer expiration (-1 if none).
  77  */
  78 static DWORD TIMER_NextExpire( DWORD curTime )
  79 {
  80     if (!pNextTimer) return -1;
  81     if (pNextTimer->expires <= curTime) return 0;
  82     return pNextTimer->expires - curTime;
  83 }
  84
  85
  86 /***********************************************************************
  87  *           TIMER_CheckTimer
  88  *
  89  * Check whether a timer has expired, and post a message if necessary.
  90  * Return TRUE if msg posted, and return time until next expiration in 'next'.
  91  */
  92 BOOL TIMER_CheckTimer( DWORD *next )
  93 {
  94     TIMER * pTimer = pNextTimer;
  95     DWORD curTime = GetTickCount();
  96
  97     if ((*next = TIMER_NextExpire( curTime )) != 0) return FALSE;
  98
  99     PostMessage( pTimer->hwnd, pTimer->msg, pTimer->id, (LONG)pTimer->proc );
 100     TIMER_RemoveTimer( pTimer );
 101
 102       /* If timeout == 0, the timer has been removed by KillTimer */
 103     if (pTimer->timeout)
 104     {
 105           /* Restart the timer */
 106         pTimer->expires = curTime + pTimer->timeout;
 107         TIMER_InsertTimer( pTimer );
 108     }
 109     *next = TIMER_NextExpire( curTime );
 110     return TRUE;
 111 }
 112
 113
 114 /***********************************************************************
 115  *           TIMER_SetTimer
 116  */
 117 static WORD TIMER_SetTimer( HWND hwnd, WORD id, WORD timeout,
 118                             FARPROC proc, BOOL sys )
 119 {
 120     int i;
 121     TIMER * pTimer;
 122
 123     if (!timeout) return 0;
 124     if (!hwnd && !proc) return 0;
 125
 126       /* Find a free timer */
 127
 128     for (i = 0, pTimer = TimersArray; i < NB_TIMERS; i++, pTimer++)
 129         if (!pTimer->timeout) break;
 130
 131     if (i >= NB_TIMERS) return 0;
 132     if (!sys && (i >= NB_TIMERS-NB_RESERVED_TIMERS)) return 0;
 133     if (!hwnd) id = i + 1;
 134
 135       /* Add the timer */
 136
 137     pTimer->hwnd    = hwnd;
 138     pTimer->msg     = sys ? WM_SYSTIMER : WM_TIMER;
 139     pTimer->id      = id;
 140     pTimer->timeout = timeout;
 141     pTimer->expires = GetTickCount() + timeout;
 142     pTimer->proc    = proc;
 143     TIMER_InsertTimer( pTimer );
 144     MSG_IncTimerCount( GetTaskQueue(0) );
 145     return id;
 146 }
 147
 148
 149 /***********************************************************************
 150  *           TIMER_KillTimer
 151  */
 152 static BOOL TIMER_KillTimer( HWND hwnd, WORD id, BOOL sys )
 153 {
 154     int i;
 155     TIMER * pTimer;
 156
 157       /* Find the timer */
 158
 159     for (i = 0, pTimer = TimersArray; i < NB_TIMERS; i++, pTimer++)
 160         if ((pTimer->hwnd == hwnd) && (pTimer->id == id) &&
 161             (pTimer->timeout != 0)) break;
 162     if (i >= NB_TIMERS) return FALSE;
 163     if (!sys && (i >= NB_TIMERS-NB_RESERVED_TIMERS)) return FALSE;
 164     if (!sys && (pTimer->msg != WM_TIMER)) return FALSE;
 165     else if (sys && (pTimer->msg != WM_SYSTIMER)) return FALSE;
 166
 167       /* Delete the timer */
 168
 169     pTimer->hwnd    = 0;
 170     pTimer->msg     = 0;
 171     pTimer->id      = 0;
 172     pTimer->timeout = 0;
 173     pTimer->proc    = 0;
 174     TIMER_RemoveTimer( pTimer );
 175     MSG_DecTimerCount( GetTaskQueue(0) );
 176     return TRUE;
 177 }
 178
 179
 180 /***********************************************************************
 181  *           SetTimer   (USER.10)
 182  */
 183 WORD SetTimer( HWND hwnd, WORD id, WORD timeout, FARPROC proc )
 184 {
 185 #ifdef DEBUG_TIMER
 186     printf( "SetTimer: %d %d %d %p\n", hwnd, id, timeout, proc );
 187 #endif
 188     return TIMER_SetTimer( hwnd, id, timeout, proc, FALSE );
 189 }
 190
 191
 192 /***********************************************************************
 193  *           SetSystemTimer   (USER.11)
 194  */
 195 WORD SetSystemTimer( HWND hwnd, WORD id, WORD timeout, FARPROC proc )
 196 {
 197 #ifdef DEBUG_TIMER
 198     printf( "SetSystemTimer: %d %d %d %p\n", hwnd, id, timeout, proc );
 199 #endif
 200     return TIMER_SetTimer( hwnd, id, timeout, proc, TRUE );
 201 }
 202
 203
 204 /***********************************************************************
 205  *           KillTimer   (USER.12)
 206  */
 207 BOOL KillTimer( HWND hwnd, WORD id )
 208 {
 209 #ifdef DEBUG_TIMER
 210     printf( "KillTimer: %d %d\n", hwnd, id );
 211 #endif
 212     return TIMER_KillTimer( hwnd, id, FALSE );
 213 }
 214
 215
 216 /***********************************************************************
 217  *           KillSystemTimer   (USER.182)
 218  */
 219 BOOL KillSystemTimer( HWND hwnd, WORD id )
 220 {
 221 #ifdef DEBUG_TIMER
 222     printf( "KillSystemTimer: %d %d\n", hwnd, id );
 223 #endif
 224     return TIMER_KillTimer( hwnd, id, TRUE );
 225 }