include/nucleus/select.h

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#ifndef XNSELECT_H
#define XNSELECT_H

#include <nucleus/thread.h>

#define XNSELECT_READ      0
#define XNSELECT_WRITE     1
#define XNSELECT_EXCEPT    2
#define XNSELECT_MAX_TYPES 3

struct xnselector {
        xnsynch_t synchbase;
        struct fds {
                fd_set expected;
                fd_set pending;
        } fds [XNSELECT_MAX_TYPES];
        xnholder_t destroy_link;
        xnqueue_t bindings; /* only used by xnselector_destroy */
};

#ifdef CONFIG_XENO_OPT_SELECT

struct xnselect {
        xnqueue_t bindings;
};

#define DECLARE_XNSELECT(name) struct xnselect name

struct xnselect_binding {
        struct xnselector *selector;
        struct xnselect *fd;
        unsigned type;
        unsigned bit_index;
        xnholder_t link;  /* link in selected fds list. */
        xnholder_t slink; /* link in selector list */
};

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

void xnselect_init(struct xnselect *select_block);

int xnselect_bind(struct xnselect *select_block,
                  struct xnselect_binding *binding,
                  struct xnselector *selector,
                  unsigned type,
                  unsigned bit_index,
                  unsigned state);

int __xnselect_signal(struct xnselect *select_block, unsigned state);

static inline int
xnselect_signal(struct xnselect *select_block, unsigned state)
{
        if (!emptyq_p(&select_block->bindings))
                return __xnselect_signal(select_block, state);
        return 0;
}

void xnselect_destroy(struct xnselect *select_block);

int xnselector_init(struct xnselector *selector);

int xnselect(struct xnselector *selector,
             fd_set *out_fds[XNSELECT_MAX_TYPES],
             fd_set *in_fds[XNSELECT_MAX_TYPES],
             int nfds,
             xnticks_t timeout, xntmode_t timeout_mode);

void xnselector_destroy(struct xnselector *selector);

int xnselect_mount(void);

int xnselect_umount(void);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#else /* !CONFIG_XENO_OPT_SELECT */
struct xnselector;
#define DECLARE_XNSELECT(name)
#define xnselect_init(block)
#define xnselect_bind(select_block,binding,selector,type,bit_index,state) \
        ({ -EBADF; })
#define xnselect_signal(block, state) ({ int __ret = 0; __ret; })
#define xnselect_destroy(block)
#endif /* !CONFIG_XENO_OPT_SELECT */

#endif /* XNSELECT_H */

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