diff options
Diffstat (limited to 'rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h')
-rw-r--r-- | rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h b/rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h new file mode 100644 index 0000000000..cba11667d0 --- /dev/null +++ b/rtkaio/sysdeps/unix/sysv/linux/kaio_misc.h @@ -0,0 +1,329 @@ +/* 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, LLL_PRIVATE); \ + } 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, \ + LLL_PRIVATE); \ + 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 */ |