retry.h

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#ifndef _GPXE_RETRY_H
#define _GPXE_RETRY_H

/** @file
 *
 * Retry timers
 *
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <gpxe/list.h>

/** Default timeout value */
#define DEFAULT_MIN_TIMEOUT ( TICKS_PER_SEC / 4 )

/** Limit after which the timeout will be deemed permanent */
#define DEFAULT_MAX_TIMEOUT ( 10 * TICKS_PER_SEC )

/** A retry timer */
struct retry_timer {
        /** List of active timers */
        struct list_head list;
        /** Timer is currently running */
        unsigned int running;
        /** Timeout value (in ticks) */
        unsigned long timeout;
        /** Minimum timeout value (in ticks)
         *
         * A value of zero means "use default timeout."
         */
        unsigned long min_timeout;
        /** Maximum timeout value before failure (in ticks)
         *
         * A value of zero means "use default timeout."
         */
        unsigned long max_timeout;
        /** Start time (in ticks) */
        unsigned long start;
        /** Retry count */
        unsigned int count;
        /** Timer expired callback
         *
         * @v timer     Retry timer
         * @v fail      Failure indicator
         *
         * The timer will already be stopped when this method is
         * called.  The failure indicator will be True if the retry
         * timeout has already exceeded @c MAX_TIMEOUT.
         */
        void ( * expired ) ( struct retry_timer *timer, int over );
};

extern void start_timer ( struct retry_timer *timer );
extern void start_timer_fixed ( struct retry_timer *timer,
                                unsigned long timeout );
extern void stop_timer ( struct retry_timer *timer );

/**
 * Start timer with no delay
 *
 * @v timer             Retry timer
 *
 * This starts the timer running with a zero timeout value.
 */
static inline void start_timer_nodelay ( struct retry_timer *timer ) {
        start_timer_fixed ( timer, 0 );
}

/**
 * Test to see if timer is currently running
 *
 * @v timer             Retry timer
 * @ret running         Non-zero if timer is running
 */
static inline __attribute__ (( always_inline )) unsigned long
timer_running ( struct retry_timer *timer ) {
        return ( timer->running );
}

#endif /* _GPXE_RETRY_H */