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 argu-
ment 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 de-
fault 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.
STANDARDS
GNU.
HISTORY
glibc 2.1.
SEE ALSO
aio(7)
Linux man-pages 6.9.1 2024-05-02 aio_init(3)
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