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Add skeleton file for eventual implementation of aio_read()

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This commit is contained in:
Gregory Nutt 2014-10-04 14:22:00 -06:00
parent 11e77192a9
commit 9e8a4dd229
7 changed files with 352 additions and 5 deletions
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38
include/aio.h
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@ -46,9 +46,37 @@
#include <signal.h>
#include <time.h>
#include <nuttx/wqueue.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* Work queue support is required. In the flat, embedded build the low-
* priority work queue is required so that the asynchronous I/O does not
* interfere with high priority driver operations. In the protected and
* kernel mode builds, user-space work queue support is required. If these
* pre-requisites are met, then asynchronous I/O support can be enabled with
* CONFIG_LIBC_AIO
*/
#ifdef CONFIG_LIBC_AIO
#ifndef CONFIG_SCHED_WORKQUEUE
# error Asynchronous I/O requiresCONFIG_SCHED_WORKQUEUE
#else
# if defined (CONFIG_BUILD_PROTECTED) || defined(CONFIG_BUILD_KERNEL)
# ifndef CONFIG_SCHED_USRWORK
# error User-space asynchronous I/O requires CONFIG_SCHED_USRWORK
# endif
# else
# ifndef CONFIG_SCHED_LPWORK
# error Flat-build asynchronous I/O requires CONFIG_SCHED_LPWORK
# endif
# endif
#endif
/* Standard Definitions *****************************************************/
/* aio_cancel return values
*
* AIO_ALLDONE - Indicates that none of the requested operations could
@ -93,6 +121,8 @@
struct aiocb
{
/* Standard fields required by POSIX */
struct sigevent aio_sigevent; /* Signal number and value */
FAR volatile void *aio_buf; /* Location of buffer */
off_t aio_offset; /* File offset */
@ -100,6 +130,10 @@ struct aiocb
int aio_fildes; /* File descriptor */
int aio_reqprio; /* Request priority offset */
int aio_lio_opcode; /* Operation to be performed */
/* Non-standard, implementation-dependent data */
struct work_s aio_work; /* Use to defer I/O to the work thread */
};
/****************************************************************************
@ -126,12 +160,16 @@ ssize_t aio_return(FAR struct aiocb *aiocbp);
int aio_suspend(FAR const struct aiocb *const list[], int nent,
FAR const struct timespec *timeout);
int aio_write(FAR struct aiocb *aiocbp);
#ifndef CONFIG_PTHREAD_DISABLE
int lio_listio(int mode, FAR struct aiocb *const list[], int nent,
FAR struct sigevent *sig);
#endif
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_LIBC_AIO */
#endif /* __INCLUDE_AIO_H */

8
libc/Kconfig
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@ -79,6 +79,14 @@ config EOL_IS_EITHER_CRLF
endchoice
config LIBC_AIO
bool "Asynchronous I/O support"
default n
depends on ((BUILD_PROTECTED || BUILD_KERNEL) && SCHED_USRWORK) || (BUILD_FLAT && SCHED_LPWORK)
---help---
Enable support for aynchronous I/O. This selection enabled the
interface declared in include/aio.h.
config LIBC_EXECFUNCS
bool "Enable exec[l|v] / posix_spawn() Support"
default n

6
libc/aio/Make.defs
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@ -33,11 +33,15 @@
#
############################################################################
ifneq ($(CONFIG_DISABLE_PTHREAD),y)
ifeq ($(CONFIG_LIBC_AIO),y)
# Add the asynchronous I/O C files to the build
CSRCS += aio_read.c
ifneq ($(CONFIG_PTHREAD_DISABLE),y)
CSRCS += lio_listio.c
endif
# Add the asynchronous I/O directory to the build

80
libc/aio/aio.h Normal file
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@ -0,0 +1,80 @@
/****************************************************************************
* libc/aio/aio.h
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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, 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
****************************************************************************/
#ifndef __LIBC_AIO_AIO_H
#define __LIBC_AIO_AIO_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <aio.h>
#include <nuttx/wqueue.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Select the appropriate work queue */
#if defined (CONFIG_BUILD_PROTECTED) || defined(CONFIG_BUILD_KERNEL)
# define AIO_QUEUE LPWORK
#else
# define AIO_QUEUE USRWORK
#endif
/****************************************************************************
* Public Types
****************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#endif /* __LIBC_AIO_AIO_H */

217
libc/aio/aio_read.c Normal file
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@ -0,0 +1,217 @@
/****************************************************************************
* libc/aio/aio_read.c
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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, 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <signal.h>
#include <aio.h>
#include <assert.h>
#include <errno.h>
#include "lib_internal.h"
#include "aio/aio.h"
#ifndef CONFIG_LIBC_AIO
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: aio_read_worker
*
* Description:
* This function executes on the worker thread and performs the
* asynchronous I/O operation.
*
* Input Parameters:
* arg - Worker argument. In this case, a pointer to an instance of
* struct aiocb cast to void *.
*
* Returned Value:
* None
*
****************************************************************************/
static void aio_read_worker(FAR void *arg)
{
FAR struct aiocb *aiocbp = (FAR struct aiocb *)arg;
DEBASSERT(arg);
#warning Missing logic
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: aio_read
*
* Description:
* The aio_read() function reads aiocbp->aio_nbytes from the file
* associated with aiocbp->aio_fildes into the buffer pointed to by
* aiocbp->aio_buf. The function call will return when the read request
* has been initiated or queued to the file or device (even when the data
* cannot be delivered immediately).
*
* The aiocbp value may be used as an argument to aio_error() and
* aio_return() in order to determine the error status and return status,
* respectively, of the asynchronous operation while it is proceeding. If
* an error condition is encountered during queuing, the function call
* will return without having initiated or queued the request. The
* requested operation takes place at the absolute position in the file as
* given by aio_offset, as if lseek() were called immediately prior to the
* operation with an offset equal to aio_offset and a whence equal to
* SEEK_SET. After a successful call to enqueue an asynchronous I/O
* operation, the value of the file offset for the file is unspecified.
*
* The aiocbp->aio_lio_opcode field will be ignored by aio_read().
*
* The aiocbp argument points to an aiocb structure. If the buffer pointed
* to by aiocbp->aio_buf or the control block pointed to by aiocbp becomes
* an illegal address prior to asynchronous I/O completion, then the
* behavior is undefined.
*
* Simultaneous asynchronous operations using the same aiocbp produce
* undefined results.
*
* For any system action that changes the process memory space while an
* synchronous I/O is outstanding to the address range being changed, the
* result of that action is undefined.
*
* Input Parameters:
* aiocbp - A pointer to an instance of struct aiocb
*
* Returned Value:
*
* The aio_read() function will return the value zero if the I/O operation
* is successfully queued; otherwise, the function will return the value
* -1 and set errno to indicate the error. The aio_read() function will
* ail if:
*
* EAGAIN - The requested asynchronous I/O operation was not queued due to
* system resource limitations.
*
* Each of the following conditions may be detected synchronously at the
* time of the call to aio_read(), or asynchronously. If any of the
* conditions below are detected synchronously, the aio_read() function
* will return -1 and set errno to the corresponding value. If any of the
* conditions below are detected asynchronously, the return status of the
* asynchronous operation is set to -1, and the error status of the
* asynchronous operation is set to the corresponding value.
*
* EBADF - The aiocbp->aio_fildes argument is not a valid file descriptor
* open for reading.
* EINVAL - The file offset value implied by aiocbp->aio_offset would be
* invalid, aiocbp->aio_reqprio is not a valid value, or
* aiocbp->aio_nbytes is an invalid value.
*
* In the case that the aio_read() successfully queues the I/O operation
* but the operation is subsequently cancelled or encounters an error, the
* return status of the asynchronous operation is one of the values
* normally returned by the read() function call. In addition, the error
* status of the asynchronous operation is set to one of the error
* statuses normally set by the read() function call, or one of the
* following values:
*
* EBADF - The aiocbp->aio_fildes argument is not a valid file descriptor
* open for reading.
* ECANCELED - The requested I/O was cancelled before the I/O completed
* due to an explicit aio_cancel() request.
* EINVAL - The file offset value implied by aiocbp->aio_offset would be
* invalid.
*
* The following condition may be detected synchronously or asynchronously:
*
* EOVERFLOW - The file is a regular file, aiobcp->aio_nbytes is greater
* than 0, and the starting offset in aiobcp->aio_offset is before the
* end-of-file and is at or beyond the offset maximum in the open file
* description associated with aiocbp->aio_fildes.
*
* POSIX Compliance:
* - The standard requires that if prioritized I/O is supported for this
* file, then the asynchronous operation will be submitted at a priority
* equal to a base scheduling priority minus aiocbp->aio_reqprio. If
* Thread Execution Scheduling is not supported, then the base scheduling
* priority is that of the calling thread.
*
* This implementation uses the NuttX work queues that run at a fixed,
* configured priority.
*
* - Most errors required in the standard are not detected at this point.
* There are no pre-queuing checks for the validity of the operation.
*
****************************************************************************/
int aio_read(FAR struct aiocb *aiocbp);
{
int ret;
DEBUGASSERT(aiocbp);
/* Defer the work to the worker thread */
ret = work_queue(AIO_QUEUE, &aiocbp->aio_work, aio_read_worker, aiocbp, 0);
if (ret < 0)
{
set_errno(ret);
return ERROR;
}
return OK;
}
#endif /* CONFIG_LIBC_AIO */

4
libc/aio/lio_listio.c
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@ -47,7 +47,7 @@
#include "lib_internal.h"
#ifndef CONFIG_DISABLE_PTHREAD
#if defined(CONFIG_LIBC_AIO) && !defined(CONFIG_PTHREAD_DISABLE)
/****************************************************************************
* Pre-processor Definitions
@ -283,4 +283,4 @@ int lio_listio(int mode, FAR struct aiocb *const list[], int nent,
return -ENOSYS;
}
#endif /* !CONFIG_DISABLE_PTHREAD */
#endif /* CONFIG_LIBC_AIO && !CONFIG_PTHREAD_DISABLE */

4
libc/lib_internal.h
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@ -51,7 +51,7 @@
#include <nuttx/streams.h>
/****************************************************************************
* Definitions
* Pre-processor Definitions
****************************************************************************/
/* This configuration directory is used in environment variable processing
* when we need to reference the user's home directory. There are no user
@ -125,7 +125,7 @@
****************************************************************************/
/****************************************************************************
* Public Variables
* Public Data
****************************************************************************/
#undef EXTERN