aio_init(3)                                           Library Functions Manual                                          aio_init(3)

NAME
       aio_init - asynchronous I/O initialization

LIBRARY
       Real-time library (librt, -lrt)

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

       void aio_init(const struct aioinit *init);

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 follow‐
       ing 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 ter‐
              minating, after having completed a previous request.  The default value is 1.

VERSIONS
       The aio_init() function is available since glibc 2.1.

STANDARDS
       This function is a GNU extension.

SEE ALSO
       aio(7)

Linux man-pages 6.03                                         2022-10-30                                                 aio_init(3)