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Initial implementation of aio_write()

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This commit is contained in:
Gregory Nutt 2014-10-04 17:30:24 -06:00
parent edb2f1a8ed
commit e8cef249cc
7 changed files with 306 additions and 7 deletions
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2
include/aio.h
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@ -135,7 +135,7 @@ struct aiocb
struct work_s aio_work; /* Used to defer I/O to the work thread */
pid_t aio_pid; /* ID of client to be notify at completion */
ssize_t aio_result; /* Support aio_error() and aio_return() */
volatile ssize_t aio_result; /* Support for aio_error() and aio_return() */
};
/****************************************************************************

2
include/fcntl.h
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@ -69,7 +69,7 @@
/* Unsupported, but required open flags */
#define O_RSYNC 0 /* Synchronize input on read */
#define O_ACCMODE 0 /* Required by POSIX */
#define O_ACCMODE O_RDWR /* Mask for access mode */
#define O_NOCTTY 0 /* Required by POSIX */
#define O_TEXT 0 /* Open the file in text (translated) mode. */

2
libc/Kconfig
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@ -460,7 +460,7 @@ if SCHED_LPWORK
config SCHED_LPWORKPRIORITY
int "Low priority worker thread priority"
default 50
default 100
---help---
The execution priority of the lopwer priority worker thread. Default: 192

2
libc/aio/Make.defs
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@ -37,7 +37,7 @@ ifeq ($(CONFIG_LIBC_AIO),y)
# Add the asynchronous I/O C files to the build
CSRCS += aio_read.c
CSRCS += aio_read.c aio_write.c
ifneq ($(CONFIG_PTHREAD_DISABLE),y)
CSRCS += lio_listio.c

4
libc/aio/aio_read.c
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@ -159,7 +159,7 @@ static void aio_read_worker(FAR void *arg)
* 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
@ -168,7 +168,7 @@ static void aio_read_worker(FAR void *arg)
* Simultaneous asynchronous operations using the same aiocbp produce
* undefined results.
*
* For any system action that changes the process memory space while an
* 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.
*

299
libc/aio/aio_write.c Normal file
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@ -0,0 +1,299 @@
/****************************************************************************
* libc/aio/aio_write.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 <unistd.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_write_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_write_worker(FAR void *arg)
{
FAR struct aiocb *aiocbp = (FAR struct aiocb *)arg;
DEBASSERT(arg);
ssize_t nwritten;
int oflags;
/* Call fcntl(F_GETFL) to get the file open mode.
*
* REVISIT: Consider moving aio_write into the kernel. Notice that in a
* system using system calls, up to three system calls may be required:
* (1) fcntl, (2) write or pwrite, and possibly (3) sigueue(). If aio_write
* were a system call, then only one would be required.
*/
oflags = fcntl((aiocbp->aio_fildes, F_GETFL, ...)
if (oflags < 0)
{
int errcode = get_errno();
fdbg("ERROR: fcntl failed: %d\n", errode);
aicbp->result = -errcode;
}
else
{
/* Perform the write using:
*
* aio_fildes - File descriptor
* aio_buf - Location of buffer
* aio_nbytes - Length of transfer
* aio_offset - File offset
*/
/* Check if O_APPEND is set in the file open flags */
if ((oflags & O_APPEND) != 0)
{
/* Append to the current file position */
nwritten = write(aiocbp->aio_fildes, aiocbp->aio_buf,
aiocbp->aio_nbytes);
}
else
{
nwritten = pwrite(aiocbp->aio_fildes, aiocbp->aio_buf,
aiocbp->aio_nbytes, aiocbp->aio_offset);
}
/* Set the result of the write */
if (nwritten < 0)
{
int errcode = get_errno();
fdbg("ERROR: write/pwrite failed: %d\n", errode);
DEBUGASSERT(errcode > 0);
aicbp->result = -errcode;
}
else
{
aicbp->result = nwritten;
}
}
/* Signal the client */
if (aiocbp->aio_sigevent.sigev_notify == SIGEV_SIGNAL)
{
int ret;
#ifdef CONFIG_CAN_PASS_STRUCTS
ret = sigqueue(aiocbp->aio_pid, aiocbp->aio_sigevent.sigev_signo,
aiocbp->aio_sigevent.sigev_value);
#else
ret = sigqueue(aiocbp->aio_pid, aiocbp->aio_sigevent.sigev_sign,
aiocbp->aio_sigevent.sigev_value.sival_ptr);
#endif
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: aio_write
*
* Description:
* The aio_write() function writes aiocbp->aio_nbytes to the file
* associated with aiocbp->aio_fildes from the buffer pointed to by
* aiocbp->aio_buf. The function call will return when the write 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.
*
* 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.
*
* If O_APPEND is not set for the file descriptor aio_fildes, then the
* requested operation will take 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.
* If O_APPEND is set for the file descriptor, write operations append to the
* file in the same order as the calls were made. 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_write().
*
* 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_write() 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_write() 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_write(), or asynchronously. If any of the
* conditions below are detected synchronously, the aio_write() 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 writing.
* 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_write() 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 write() function call. In addition, the error
* status of the asynchronous operation is set to one of the error
* statuses normally set by the write() function call, or one of the
* following values:
*
* EBADF - The aiocbp->aio_fildes argument is not a valid file descriptor
* open for writing.
* EINVAL - The file offset value implied by aiocbp->aio_offset would be
* invalid.
* ECANCELED - The requested I/O was cancelled before the I/O completed
* due to an explicit aio_cancel() request.
*
* The following condition may be detected synchronously or asynchronously:
*
* EFBIG - The file is a regular file, aiobcp->aio_nbytes is greater
* than 0, and the starting offset in aiobcp->aio_offset 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
* Thwrite 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_write(FAR struct aiocb *aiocbp);
{
int ret;
DEBUGASSERT(aiocbp);
/* The result -EBUSY means that the transfer has not yet completed */
aiocbp->aio_result = -EBUSY;
/* Save the ID of the calling, client thread */
aiocbp->aio_pid = getpid();
/* Defer the work to the worker thread */
ret = work_queue(AIO_QUEUE, &aiocbp->aio_work, aio_write_worker, aiocbp, 0);
if (ret < 0)
{
aio->aio_result = ret;
set_errno(ret);
return ERROR;
}
return OK;
}
#endif /* CONFIG_LIBC_AIO */

2
libc/aio/lio_listio.c
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@ -164,7 +164,7 @@ static pthread_addr_t lio_thread(pthread_addr_t arg)
*
* If the buffer pointed to by 'list' or the aiocb structures pointed to
* by the elements of the array 'list' become illegal addresses before all
* asynchronous I/O completed and, if necessary, the notification is
* asynchronous I/O completed and, if necessary, the notification is
* sent, then the behavior is undefined. If the buffers pointed to by the
* aio_buf member of the aiocb structure pointed to by the elements of
* the array 'list' become illegal addresses prior to the asynchronous