freebsd-skq/lib/librt/aio.c
davidxu 8e36ba772a Use a thread pool to process notification if sigev_notify_attributes
is default and caller does not require dedicated thread. timer needs
a dedicated thread to maintain overrun count correctly in notification
context. mqueue and aio can use thread pool to do notification
concurrently, the thread pool has lifecycle control, some threads will
exit if they have idled for a while.
2006-03-04 00:18:19 +00:00

163 lines
4.2 KiB
C

/*
* Copyright (c) 2005 David Xu <davidxu@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <sys/aio.h>
#include "namespace.h"
#include <errno.h>
#include <pthread.h>
#include <stddef.h>
#include <signal.h>
#include <unistd.h>
#include "sigev_thread.h"
#include "un-namespace.h"
__weak_reference(__aio_read, _aio_read);
__weak_reference(__aio_read, aio_read);
__weak_reference(__aio_write, _aio_write);
__weak_reference(__aio_write, aio_write);
__weak_reference(__aio_return, _aio_return);
__weak_reference(__aio_return, aio_return);
__weak_reference(__aio_waitcomplete, _aio_waitcomplete);
__weak_reference(__aio_waitcomplete, aio_waitcomplete);
typedef void (*aio_func)(union sigval val, struct aiocb *iocb);
extern int __sys_aio_read(struct aiocb *iocb);
extern int __sys_aio_write(struct aiocb *iocb);
extern int __sys_aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout);
extern int __sys_aio_return(struct aiocb *iocb);
extern int __sys_aio_error(struct aiocb *iocb);
static void
aio_dispatch(struct sigev_node *sn)
{
aio_func f = sn->sn_func;
f(sn->sn_value, (struct aiocb *)sn->sn_id);
}
static int
aio_io(struct aiocb *iocb, int (*sysfunc)(struct aiocb *iocb))
{
struct sigev_node *sn;
struct sigevent saved_ev;
int ret, err;
if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD) {
ret = sysfunc(iocb);
return (ret);
}
if (__sigev_check_init()) {
/* This might be that thread library is not enabled. */
errno = EINVAL;
return (-1);
}
sn = __sigev_alloc(SI_ASYNCIO, &iocb->aio_sigevent, NULL, 1);
if (sn == NULL) {
errno = EAGAIN;
return (-1);
}
saved_ev = iocb->aio_sigevent;
sn->sn_id = (sigev_id_t)iocb;
sn->sn_flags |= SNF_ONESHOT;
__sigev_get_sigevent(sn, &iocb->aio_sigevent, sn->sn_id);
__sigev_list_lock();
__sigev_register(sn);
__sigev_list_unlock();
sn->sn_dispatch = aio_dispatch;
ret = sysfunc(iocb);
iocb->aio_sigevent = saved_ev;
if (ret != 0) {
err = errno;
__sigev_list_lock();
__sigev_delete_node(sn);
__sigev_list_unlock();
errno = err;
}
return (ret);
}
int
__aio_read(struct aiocb *iocb)
{
return aio_io(iocb, &__sys_aio_read);
}
int
__aio_write(struct aiocb *iocb)
{
return aio_io(iocb, &__sys_aio_write);
}
int
__aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout)
{
int err;
int ret = __sys_aio_waitcomplete(iocbp, timeout);
if (*iocbp) {
if ((*iocbp)->aio_sigevent.sigev_notify == SIGEV_THREAD) {
err = errno;
__sigev_list_lock();
__sigev_delete(SI_ASYNCIO, (sigev_id_t)(*iocbp));
__sigev_list_unlock();
errno = err;
}
}
return (ret);
}
int
__aio_return(struct aiocb *iocb)
{
if (iocb->aio_sigevent.sigev_notify == SIGEV_THREAD) {
if (__sys_aio_error(iocb) == EINPROGRESS)
return (EINPROGRESS);
__sigev_list_lock();
__sigev_delete(SI_ASYNCIO, (sigev_id_t)iocb);
__sigev_list_unlock();
}
return __sys_aio_return(iocb);
}