pool.h

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#ifndef _IPXE_POOL_H
#define _IPXE_POOL_H

/** @file
 *
 * Pooled connections
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <ipxe/interface.h>
#include <ipxe/list.h>
#include <ipxe/retry.h>

/** A pooled connection */
struct pooled_connection {
        /** List of pooled connections
         *
         * Note that each connecton in the pool has a running expiry
         * timer which holds a reference to the connection.  We
         * therefore do not require the connection pool list to hold a
         * reference for each pooled connection.
         */
        struct list_head list;
        /** Expiry timer */
        struct retry_timer timer;
        /** Close expired pooled connection
         *
         * @v pool              Pooled connection
         */
        void ( * expired ) ( struct pooled_connection *pool );
        /** Flags */
        unsigned int flags;
};

/** Pooled connection flags */
enum pooled_connection_flags {
        /** Connection should be recycled after closing */
        POOL_RECYCLABLE = 0x0001,
        /** Connection has been recycled */
        POOL_RECYCLED = 0x0002,
        /** Connection is known to be alive */
        POOL_ALIVE = 0x0004,
};

extern void pool_add ( struct pooled_connection *pool, struct list_head *list,
                       unsigned long expiry );
extern void pool_del ( struct pooled_connection *pool );
extern void pool_expired ( struct retry_timer *timer, int over );

/**
 * Initialise a pooled connection
 *
 * @v pool              Pooled connection
 * @v expired           Close expired pooled connection method
 * @v refcnt            Containing object reference counter
 */
static inline __attribute__ (( always_inline )) void
pool_init ( struct pooled_connection *pool,
            void ( * expired ) ( struct pooled_connection *pool ),
            struct refcnt *refcnt ) {

        INIT_LIST_HEAD ( &pool->list );
        timer_init ( &pool->timer, pool_expired, refcnt );
        pool->expired = expired;
}

/**
 * Mark pooled connection as recyclable
 *
 * @v pool              Pooled connection
 */
static inline __attribute__ (( always_inline )) void
pool_recyclable ( struct pooled_connection *pool ) {

        pool->flags |= POOL_RECYCLABLE;
}

/**
 * Mark pooled connection as alive
 *
 * @v pool              Pooled connection
 */
static inline __attribute__ (( always_inline )) void
pool_alive ( struct pooled_connection *pool ) {

        pool->flags |= POOL_ALIVE;
}

/**
 * Check if pooled connection is recyclable
 *
 * @v pool              Pooled connection
 * @ret recyclable      Pooled connection is recyclable
 */
static inline __attribute__ (( always_inline )) int
pool_is_recyclable ( struct pooled_connection *pool ) {

        return ( pool->flags & POOL_RECYCLABLE );
}

/**
 * Check if pooled connection is reopenable
 *
 * @v pool              Pooled connection
 * @ret reopenable      Pooled connection is reopenable
 */
static inline __attribute__ (( always_inline )) int
pool_is_reopenable ( struct pooled_connection *pool ) {

        /* A connection is reopenable if it has been recycled but is
         * not yet known to be alive.
         */
        return ( ( pool->flags & POOL_RECYCLED ) &&
                 ( ! ( pool->flags & POOL_ALIVE ) ) );
}

extern void pool_recycle ( struct interface *intf );
#define pool_recycle_TYPE( object_type ) \
        typeof ( void ( object_type ) )

extern void pool_reopen ( struct interface *intf );
#define pool_reopen_TYPE( object_type ) \
        typeof ( void ( object_type ) )

#endif /* _IPXE_POOL_H */