rx/rx_event.h

   1 /*
   2 ****************************************************************************
   3 *        Copyright IBM Corporation 1988, 1989 - All Rights Reserved        *
   4 *                                                                          *
   5 * Permission to use, copy, modify, and distribute this software and its    *
   6 * documentation for any purpose and without fee is hereby granted,         *
   7 * provided that the above copyright notice appear in all copies and        *
   8 * that both that copyright notice and this permission notice appear in     *
   9 * supporting documentation, and that the name of IBM not be used in        *
  10 * advertising or publicity pertaining to distribution of the software      *
  11 * without specific, written prior permission.                              *
  12 *                                                                          *
  13 * IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL *
  14 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL IBM *
  15 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY      *
  16 * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER  *
  17 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING   *
  18 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.    *
  19 ****************************************************************************
  20 */
  21
  22 /* Event package */
  23
  24 #ifndef _EVENT_
  25 #define _EVENT_
  26
  27 #ifdef  KERNEL
  28 #include "../rx/rx_queue.h"
  29 #include "../rx/rx_clock.h"
  30 #else                                  /* KERNEL */
  31 #include "rx_queue.h"
  32 #include "rx_clock.h"
  33 #endif                                 /* KERNEL */
  34
  35 /*
  36  * An event is something that will happen at (or after) a specified clock
  37  * time, unless cancelled prematurely.  The user routine (*func)() is called
  38  * with arguments (event, arg, arg1) when the event occurs.  Warnings:
  39  * (1) The user supplied routine should NOT cause process preemption.
  40  * (2) The event passed to the user is still on the event queue at that time.
  41  * The user must not remove (event_Cancel) it explicitly, but the user may
  42  * remove or schedule any OTHER event at this time.
  43  */
  44
  45 struct rxevent {
  46     struct rx_queue junk;              /* Events are queued */
  47     struct clock eventTime;            /* When this event times out (in
  48                                         * clock.c units) */
  49     void (*func)();                    /* Function to call when this expires */
  50     void *arg;                         /* Argument to the function */
  51     void *arg1;                        /* Another argument */
  52 };
  53
  54 /*
  55  * Some macros to make macros more reasonable (this allows a block to be
  56  * used within a macro which does not cause if statements to screw up).
  57  * That is, you can use "if (...) macro_name(); else ...;" without having
  58  * things blow up on the semi-colon.
  59  */
  60
  61 #ifndef BEGIN
  62 #define BEGIN do {
  63 #define END } while(0)
  64 #endif
  65
  66 /*
  67  * This routine must be called to initialize the event package.
  68  * nEvents is the number of events to allocate in a batch whenever more
  69  * are needed.  If this is 0, a default number (10) will be allocated.
  70  */
  71 void rxevent_Init(int, void (*)());
  72
  73 /*
  74  * Arrange for the indicated event at the appointed time.  When is a
  75  * "struct clock", in the clock.c time base
  76  */
  77 struct rxevent *rxevent_Post(struct clock*, void (*)(), void*, void*);
  78
  79 /*
  80  * Remove the indicated event from the event queue.  The event must be
  81  * pending.  Also see the warning, above.  The event pointer supplied is
  82  * zeroed.
  83  */
  84 void rxevent_Cancel_1(struct rxevent *);
  85
  86 #define rxevent_Cancel(event_ptr)                   \
  87         BEGIN                                       \
  88             if (event_ptr) {                        \
  89                 rxevent_Cancel_1(event_ptr);        \
  90                 event_ptr = (struct rxevent *) 0;   \
  91             }                                       \
  92         END
  93
  94 /*
  95  * The actions specified for each event that has reached the current clock
  96  * time will be taken.  The current time returned by GetTime is used
  97  * (warning: this may be an old time if the user has not called clock_NewTime)
  98  */
  99 int rxevent_RaiseEvents(struct clock *);
 100
 101 #endif                                 /* _EVENT_ */