src/include/gpxe/retry.h

   1 #ifndef _GPXE_RETRY_H
   2 #define _GPXE_RETRY_H
   3
   4 /** @file
   5  *
   6  * Retry timers
   7  *
   8  */
   9
  10 FILE_LICENCE ( GPL2_OR_LATER );
  11
  12 #include <gpxe/list.h>
  13
  14 /** Default timeout value */
  15 #define DEFAULT_MIN_TIMEOUT ( TICKS_PER_SEC / 4 )
  16
  17 /** Limit after which the timeout will be deemed permanent */
  18 #define DEFAULT_MAX_TIMEOUT ( 10 * TICKS_PER_SEC )
  19
  20 /** A retry timer */
  21 struct retry_timer {
  22         /** List of active timers */
  23         struct list_head list;
  24         /** Timer is currently running */
  25         unsigned int running;
  26         /** Timeout value (in ticks) */
  27         unsigned long timeout;
  28         /** Minimum timeout value (in ticks)
  29          *
  30          * A value of zero means "use default timeout."
  31          */
  32         unsigned long min_timeout;
  33         /** Maximum timeout value before failure (in ticks)
  34          *
  35          * A value of zero means "use default timeout."
  36          */
  37         unsigned long max_timeout;
  38         /** Start time (in ticks) */
  39         unsigned long start;
  40         /** Retry count */
  41         unsigned int count;
  42         /** Timer expired callback
  43          *
  44          * @v timer     Retry timer
  45          * @v fail      Failure indicator
  46          *
  47          * The timer will already be stopped when this method is
  48          * called.  The failure indicator will be True if the retry
  49          * timeout has already exceeded @c MAX_TIMEOUT.
  50          */
  51         void ( * expired ) ( struct retry_timer *timer, int over );
  52 };
  53
  54 /**
  55  * Initialise a timer
  56  *
  57  * @v timer             Retry timer
  58  * @v expired           Timer expired callback
  59  */
  60 static inline __attribute__ (( always_inline )) void
  61 timer_init ( struct retry_timer *timer,
  62              void ( * expired ) ( struct retry_timer *timer, int over ) ) {
  63         timer->expired = expired;
  64 }
  65
  66 extern void start_timer ( struct retry_timer *timer );
  67 extern void start_timer_fixed ( struct retry_timer *timer,
  68                                 unsigned long timeout );
  69 extern void stop_timer ( struct retry_timer *timer );
  70
  71 /**
  72  * Start timer with no delay
  73  *
  74  * @v timer             Retry timer
  75  *
  76  * This starts the timer running with a zero timeout value.
  77  */
  78 static inline void start_timer_nodelay ( struct retry_timer *timer ) {
  79         start_timer_fixed ( timer, 0 );
  80 }
  81
  82 /**
  83  * Test to see if timer is currently running
  84  *
  85  * @v timer             Retry timer
  86  * @ret running         Non-zero if timer is running
  87  */
  88 static inline __attribute__ (( always_inline )) unsigned long
  89 timer_running ( struct retry_timer *timer ) {
  90         return ( timer->running );
  91 }
  92
  93 #endif /* _GPXE_RETRY_H */