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/* Copyright (C) 1997,1999,2000,2001,2002,2003,2006
Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _AIO_MISC_H
#include <sysdep.h>
#if !defined __NR_io_setup || !defined __NR_io_destroy \
|| !defined __NR_io_getevents || !defined __NR_io_submit \
|| !defined __NR_io_cancel
#include <aio_misc.h>
#else
#define _AIO_MISC_H 1
#define USE_KAIO 1
#include <aio.h>
#include <pthread.h>
#include <stdint.h>
#include <signal.h>
#include <sysdep.h>
#include <limits.h>
#ifdef HAVE_FORCED_UNWIND
/* We define a special synchronization primitive for AIO. POSIX
conditional variables would be ideal but the pthread_cond_*wait
operations do not return on EINTR. This is a requirement for
correct aio_suspend and lio_listio implementations. */
#include <assert.h>
#include <pthreadP.h>
#include <lowlevellock.h>
# define DONT_NEED_AIO_MISC_COND 1
# define AIO_MISC_NOTIFY(waitlist) \
do { \
if (*waitlist->counterp > 0 && --*waitlist->counterp == 0) \
lll_futex_wake (waitlist->counterp, 1); \
} while (0)
# define AIO_MISC_WAIT(result, futex, timeout, cancel) \
do { \
volatile int *futexaddr = &futex; \
int oldval = futex; \
\
if (oldval != 0) \
{ \
pthread_mutex_unlock (&__aio_requests_mutex); \
\
int oldtype; \
if (cancel) \
oldtype = LIBC_CANCEL_ASYNC (); \
\
int status; \
do \
{ \
status = lll_futex_timed_wait (futexaddr, oldval, timeout); \
if (status != -EWOULDBLOCK) \
break; \
\
oldval = *futexaddr; \
} \
while (oldval != 0); \
\
if (cancel) \
LIBC_CANCEL_RESET (oldtype); \
\
if (status == -EINTR) \
result = EINTR; \
else if (status == -ETIMEDOUT) \
result = EAGAIN; \
else \
assert (status == 0 || status == -EWOULDBLOCK); \
\
pthread_mutex_lock (&__aio_requests_mutex); \
} \
} while (0)
#endif
typedef unsigned long kctx_t;
#define KCTX_NONE ~0UL
extern kctx_t __aio_kioctx;
enum
{
IO_CMD_PREAD,
IO_CMD_PWRITE,
IO_CMD_FSYNC,
IO_CMD_FDSYNC,
IO_CMD_PREADX,
IO_CMD_POLL
};
struct kiocb
{
uint64_t kiocb_data;
uint64_t kiocb_key;
uint16_t kiocb_lio_opcode;
int16_t kiocb_req_prio;
uint32_t kiocb_fildes;
uint64_t kiocb_buf;
uint64_t kiocb_nbytes;
int64_t kiocb_offset;
int64_t __pad3, __pad4;
};
struct kio_event
{
uint64_t kioe_data;
uint64_t kioe_obj;
int64_t kioe_res;
int64_t kioe_res2;
};
/* Extend the operation enum. */
enum
{
LIO_DSYNC = LIO_NOP + 1,
LIO_SYNC,
LIO_READ64 = LIO_READ | 128,
LIO_WRITE64 = LIO_WRITE | 128,
LIO_KTHREAD = 0x10000,
LIO_KTHREAD_REQUIRED = 0x20000
};
/* Union of the two request types. */
typedef union
{
struct aiocb aiocb;
struct aiocb64 aiocb64;
} aiocb_union;
/* Used to synchronize. */
struct waitlist
{
struct waitlist *next;
/* The next two fields is used in synchronous io_listio' operations. */
#ifndef DONT_NEED_AIO_MISC_COND
pthread_cond_t *cond;
#endif
int *result;
volatile int *counterp;
/* The next field is used in asynchronous `lio_listio' operations. */
struct sigevent *sigevp;
#ifdef BROKEN_THREAD_SIGNALS
/* XXX See requestlist, it's used to work around the broken signal
handling in Linux. */
pid_t caller_pid;
#endif
};
/* Status of a request. */
enum
{
no,
queued,
yes,
allocated,
done
};
/* Used to queue requests.. */
struct requestlist
{
struct kiocb kiocb;
kctx_t kioctx;
int running;
struct requestlist *last_fd;
struct requestlist *next_fd;
struct requestlist *next_prio;
struct requestlist *next_run;
/* For kioctx != KCTX_NONE requests we are doubly linked. */
#define prev_prio next_run
/* Pointer to the actual data. */
aiocb_union *aiocbp;
#ifdef BROKEN_THREAD_SIGNALS
/* PID of the initiator thread.
XXX This is only necessary for the broken signal handling on Linux. */
pid_t caller_pid;
#endif
/* List of waiting processes. */
struct waitlist *waiting;
};
/* Lock for global I/O list of requests. */
extern pthread_mutex_t __aio_requests_mutex attribute_hidden;
/* Enqueue request. */
extern struct requestlist *__aio_enqueue_request_ctx (aiocb_union *aiocbp,
int operation,
kctx_t kctx)
attribute_hidden internal_function;
#define __aio_enqueue_request(aiocbp, operation) \
__aio_enqueue_request_ctx (aiocbp, operation | LIO_KTHREAD, KCTX_NONE)
/* Find request entry for given AIO control block. */
extern struct requestlist *__aio_find_req (aiocb_union *elem)
attribute_hidden internal_function;
/* Find request entry for given file descriptor. */
extern struct requestlist *__aio_find_req_fd (int fildes)
attribute_hidden internal_function;
/* Find request entry for given file descriptor. */
extern struct requestlist *__aio_find_kreq_fd (int fildes)
attribute_hidden internal_function;
/* Remove request from the list. */
extern void __aio_remove_request (struct requestlist *last,
struct requestlist *req, int all)
attribute_hidden internal_function;
extern void __aio_remove_krequest (struct requestlist *req)
attribute_hidden internal_function;
/* Release the entry for the request. */
extern void __aio_free_request (struct requestlist *req)
attribute_hidden internal_function;
/* Notify initiator of request and tell this everybody listening. */
extern void __aio_notify (struct requestlist *req)
attribute_hidden internal_function;
/* Notify initiator of request. */
#ifdef BROKEN_THREAD_SIGNALS
extern int __aio_notify_only (struct sigevent *sigev, pid_t caller_pid)
attribute_hidden internal_function;
#else
extern int __aio_notify_only (struct sigevent *sigev)
attribute_hidden internal_function;
#endif
/* Send the signal. */
extern int __aio_sigqueue (int sig, const union sigval val, pid_t caller_pid)
attribute_hidden internal_function;
extern int __aio_wait_for_events (kctx_t kctx, const struct timespec *timeout)
attribute_hidden internal_function;
extern void __aio_read_one_event (void) attribute_hidden internal_function;
extern int __aio_create_kernel_thread (void)
attribute_hidden internal_function;
extern int __have_no_kernel_aio attribute_hidden;
extern int __kernel_thread_started attribute_hidden;
#ifndef BROKEN_THREAD_SIGNALS
# define aio_start_notify_thread __aio_start_notify_thread
# define aio_create_helper_thread __aio_create_helper_thread
extern inline void
__aio_start_notify_thread (void)
{
sigset_t ss;
sigemptyset (&ss);
INTERNAL_SYSCALL_DECL (err);
INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &ss, NULL, _NSIG / 8);
}
extern inline int
__aio_create_helper_thread (pthread_t *threadp, void *(*tf) (void *), void *arg)
{
pthread_attr_t attr;
/* Make sure the thread is created detached. */
pthread_attr_init (&attr);
pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
/* The helper thread needs only very little resources. */
(void) pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN);
/* Block all signals in the helper thread. To do this thoroughly we
temporarily have to block all signals here. */
sigset_t ss;
sigset_t oss;
sigfillset (&ss);
INTERNAL_SYSCALL_DECL (err);
INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &ss, &oss, _NSIG / 8);
int ret = pthread_create (threadp, &attr, tf, arg);
/* Restore the signal mask. */
INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &oss, NULL,
_NSIG / 8);
(void) pthread_attr_destroy (&attr);
return ret;
}
#endif
#endif
#endif /* aio_misc.h */
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