eventfd_ctx_fileget(9) [centos man page]

EVENTFD_CTX_FILEGET(9)					  Events based on file descripto				    EVENTFD_CTX_FILEGET(9)

NAME

       eventfd_ctx_fileget - Acquires a reference to the internal eventfd context.

SYNOPSIS

       struct eventfd_ctx * eventfd_ctx_fileget(struct file * file);

ARGUMENTS

       file
	   [in] Eventfd file pointer.

DESCRIPTION

       Returns a pointer to the internal eventfd context, otherwise the error

POINTER

       -EINVAL : The fd file descriptor is not an eventfd file.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						    EVENTFD_CTX_FILEGET(9)

iv_event_raw(3) 					    ivykis programmer's manual						   iv_event_raw(3)

NAME

       IV_EVENT_RAW_INIT, iv_event_raw_register, iv_event_raw_unregister, iv_event_raw_post - manage ivykis objects for event notification

SYNOPSIS

       #include <iv_event_raw.h>

       struct iv_event_raw {
	       void	       *cookie;
	       void	       (*handler)(void *);
       };

       void IV_EVENT_RAW_INIT(struct iv_event_raw *this);
       int iv_event_raw_register(struct iv_event_raw *this);
       void iv_event_raw_unregister(struct iv_event_raw *this);
       void iv_event_raw_post(struct iv_event_raw *this);

DESCRIPTION

       iv_event_raw provides a way for delivering events to ivykis(3) recipients across thread and process boundaries.

       The  intended  event  recipient	calls  IV_EVENT_RAW_INIT  on a struct iv_event_raw object, fills in ->cookie and ->handler, and then calls
       iv_event_raw_register on the object.

       To generate an event, call iv_event_raw_post on the previously initialized struct iv_event_raw object.  This will cause the callback speci-
       fied by ->handler to be called in the thread that the struct iv_event_raw object was registered in, with ->cookie as its sole argument.

       To  deinitialize a struct iv_event_raw object, call iv_event_raw_unregister from the same thread that iv_event_raw_register was called from
       on that object.

       It is permitted to unregister a struct iv_event_raw object from any ivykis callback function in the thread it was registered in,  including
       from  a callback function triggered by this object, and it is permitted to free the memory corresponding to an unregistered object from its
       own callback function.

       iv_event_raw_post can be called from the same thread that iv_event_raw_register was called from,  from  a  different  thread  in  the  same
       process, or even from a different process, and can safely be called from signal handlers.

       If  posting  an	event  only  ever  needs  to  be  done	from  within the same process, see iv_event(3) for a lighter-weight alternative to
       iv_event_raw.

       Internally, iv_event_raw is implemented by registering a file descriptor (a struct iv_fd(3)) with the recipient thread's ivykis event loop,
       and by causing that file descriptor to become readable upon a call to iv_event_raw_post.

       If  eventfd(2) is available, it will be used to procure the abovementioned file descriptor.  If not, iv_event_raw will fall back to pipe(2)
       as the source of its file descriptors.  eventfd(2) is preferred as it requires only one file descriptor table entry (while pipe(2) requires
       two), and has much less kernel overhead than pipe(2) has.

SEE ALSO

       ivykis(3), iv_event(3), eventfd(2), pipe(2)

ivykis								    2010-09-02							   iv_event_raw(3)