NAME

       aio_init - POSIX asynchronous I/O initialization

SYNOPSIS

       #define _GNU_SOURCE         /* See feature_test_macros(7) */
       #include <aio.h>

       void aio_init(const struct aioinit *init);

       Link with -lrt.

DESCRIPTION

       The  GNU-specific  aio_init()  function  allows  the  caller to provide
       tuning hints to the  glibc  POSIX  AIO  implementation.   Use  of  this
       function  is  optional,  but  to be effective, it must be called before
       employing any other functions in the POSIX AIO API.

       The tuning information is provided in the  buffer  pointed  to  by  the
       argument init.  This buffer is a structure of the following form:

           struct aioinit {
               int aio_threads;    /* Maximum number of threads */
               int aio_num;        /* Number of expected simultaneous
                                      requests */
               int aio_locks;      /* Not used */
               int aio_usedba;     /* Not used */
               int aio_debug;      /* Not used */
               int aio_numusers;   /* Not used */
               int aio_idle_time;  /* Number of seconds before idle thread
                                      terminates (since glibc 2.2) */
               int aio_reserved;
           };

       The following fields are used in the aioinit structure:

       aio_threads    This  field  specifies  the  maximum  number  of  worker
                      threads that may be used by the implementation.  If  the
                      number of outstanding I/O operations exceeds this limit,
                      then excess operations will be  queued  until  a  worker
                      thread  becomes free.  If this field is specified with a
                      value less than 1, the value 1  is  used.   The  default
                      value is 20.

       aio_num        This   field   should  specify  the  maximum  number  of
                      simultaneous I/O requests that  the  caller  expects  to
                      enqueue.   If a value less than 32 is specified for this
                      field, it is rounded up to 32.  The default value is 64.

       aio_idle_time  This field specifies the amount of time in seconds  that
                      a  worker thread should wait for further requests before
                      terminating, after having completed a previous  request.
                      The default value is 1.

VERSIONS

       The aio_init() function is available since glibc 2.1.

CONFORMING TO

       This function is a GNU extension.

SEE ALSO

       aio(7)

COLOPHON

       This  page  is  part of release 3.32 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.