sergiotarxz/nuttx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

FS: Add logic to detach a file structure from a file descriptor. This is for use only within the OS. It permits an open file or driver to be used across multiple threads.

Browse Source
This commit is contained in:
Gregory Nutt 2016-05-26 09:41:50 -06:00
parent aa7a981674
commit 001715d57b
9 changed files with 339 additions and 50 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
ChangeLog
View File

@ -11810,3 +11810,6 @@
driver already supports a 1-wire interface, but this driver uses the
same serial logic to implement a lower half driver much like the I2C
lower half driver. From Aleksandr Vyhovanec (2015-05-25).
* fs/: Add logic to detach a file structure from a file descriptor.
This is for use only within the OS. It permits an open file or driver
to be used across multiple threads (2016-05-26).

37
configs/nucleo-f4x1re/src/stm32_ajoystick.c
View File

@ -46,6 +46,7 @@
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <nuttx/fs/fs.h>
#include <nuttx/input/ajoystick.h>
#include "stm32_gpio.h"
@ -108,10 +109,6 @@
AJOY_BUTTON_7_BIT )
#endif
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
@ -158,9 +155,9 @@ static const struct ajoy_lowerhalf_s g_ajoylower =
};
#ifndef NO_JOYSTICK_ADC
/* Descriptor for the open ADC driver */
/* Thread-independent file structure for the open ADC driver */
static int g_adcfd = -1;
static struct file g_adcfile;
#endif
/* Current interrupt handler and argument */
@ -209,7 +206,7 @@ static int ajoy_sample(FAR const struct ajoy_lowerhalf_s *lower,
* channels are enabled).
*/
nread = read(g_adcfd, adcmsg, MAX_ADC_CHANNELS * sizeof(struct adc_msg_s));
nread = file_read(&g_adcfile, adcmsg, MAX_ADC_CHANNELS * sizeof(struct adc_msg_s));
if (nread < 0)
{
int errcode = get_errno();
@ -454,6 +451,8 @@ int board_ajoy_initialize(void)
int i;
#ifndef NO_JOYSTICK_ADC
int fd;
ivdbg("Initialize ADC driver: /dev/adc0\n");
/* Initialize ADC. We will need this to read the ADC inputs */
@ -465,18 +464,27 @@ int board_ajoy_initialize(void)
return ret;
}
/* Open the ADC driver for reading.
* REVISIT: This can't work! The file descriptor is only valid in the
* task that opened the file. Not useful for a sharable driver.
*/
/* Open the ADC driver for reading. */
g_adcfd = open("/dev/adc0", O_RDONLY);
if (g_adcfd < 0)
fd = open("/dev/adc0", O_RDONLY);
if (fd < 0)
{
int errcode = get_errno();
idbg("ERROR: Failed to open /dev/adc0: %d\n", errcode);
return -errcode;
}
/* Detach the file structure from the file descriptor so that it can be
* used on any thread.
*/
ret = file_detach(fd, &g_adcfile);
if (ret < 0)
{
idbg("ERROR: Failed to detach from file descriptor: %d\n", ret);
(void)close(fd);
return ret;
}
#endif
/* Configure the GPIO pins as interrupting inputs. NOTE: This is
@ -500,8 +508,7 @@ int board_ajoy_initialize(void)
{
idbg("ERROR: ajoy_register failed: %d\n", ret);
#ifndef NO_JOYSTICK_ADC
close(g_adcfd);
g_adcfd = -1;
file_close_detached(&g_adcfile);
#endif
}

36
configs/nucleo-l476rg/src/stm32_ajoystick.c
View File

@ -1,7 +1,7 @@
/****************************************************************************
* configs/nucleo-f3x1re/src/stm32_ajoystick.c
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Copyright (C) 2014, 2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -45,6 +45,7 @@
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/fs/fs.h>
#include <nuttx/input/ajoystick.h>
#include "stm32l4_gpio.h"
@ -107,10 +108,6 @@
AJOY_BUTTON_7_BIT )
#endif
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
@ -157,9 +154,9 @@ static const struct ajoy_lowerhalf_s g_ajoylower =
};
#ifndef NO_JOYSTICK_ADC
/* Descriptor for the open ADC driver */
/* Thread-independent file structure for the open ADC driver */
static int g_adcfd = -1;
static struct file g_adcfile;
#endif
/* Current interrupt handler and argument */
@ -208,7 +205,7 @@ static int ajoy_sample(FAR const struct ajoy_lowerhalf_s *lower,
* channels are enabled).
*/
nread = read(g_adcfd, adcmsg, MAX_ADC_CHANNELS * sizeof(struct adc_msg_s));
nread = file_read(&g_adcfile, adcmsg, MAX_ADC_CHANNELS * sizeof(struct adc_msg_s));
if (nread < 0)
{
int errcode = get_errno();
@ -453,6 +450,8 @@ int board_ajoy_initialize(void)
int i;
#ifndef NO_JOYSTICK_ADC
int fd;
ivdbg("Initialize ADC driver: /dev/adc0\n");
/* Initialize ADC. We will need this to read the ADC inputs */
@ -464,15 +463,27 @@ int board_ajoy_initialize(void)
return ret;
}
/* Open the ADC driver for reading */
/* Open the ADC driver for reading. */
g_adcfd = open("/dev/adc0", O_RDONLY);
if (g_adcfd < 0)
fd = open("/dev/adc0", O_RDONLY);
if (fd < 0)
{
int errcode = get_errno();
idbg("ERROR: Failed to open /dev/adc0: %d\n", errcode);
return -errcode;
}
/* Detach the file structure from the file descriptor so that it can be
* used on any thread.
*/
ret = file_detach(fd, &g_adcfile);
if (ret < 0)
{
idbg("ERROR: Failed to detach from file descriptor: %d\n", ret);
(void)close(fd);
return ret;
}
#endif
/* Configure the GPIO pins as interrupting inputs. NOTE: This is
@ -496,8 +507,7 @@ int board_ajoy_initialize(void)
{
idbg("ERROR: ajoy_register failed: %d\n", ret);
#ifndef NO_JOYSTICK_ADC
close(g_adcfd);
g_adcfd = -1;
file_close_detached(&g_adcfile);
#endif
}

36
configs/sama5d3-xplained/src/sam_ajoystick.c
View File

@ -46,6 +46,7 @@
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <nuttx/fs/fs.h>
#include <nuttx/input/ajoystick.h>
#include "sam_pio.h"
@ -93,10 +94,6 @@
AJOY_BUTTON_5_BIT | AJOY_BUTTON_6_BIT | \
AJOY_BUTTON_7_BIT )
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
@ -141,9 +138,9 @@ static const struct ajoy_lowerhalf_s g_ajoylower =
.al_enable = ajoy_enable,
};
/* Descriptor for the open ADC driver */
/* Thread-independent file structure for the open ADC driver */
static int g_adcfd = -1;
static struct file g_adcfile;
/* Current interrupt handler and argument */
@ -190,7 +187,7 @@ static int ajoy_sample(FAR const struct ajoy_lowerhalf_s *lower,
* channels are enabled).
*/
nread = read(g_adcfd, adcmsg, SAM_ADC_NCHANNELS * sizeof(struct adc_msg_s));
nread = file_read(&g_adcfile, adcmsg, MAX_ADC_CHANNELS * sizeof(struct adc_msg_s));
if (nread < 0)
{
int errcode = get_errno();
@ -405,6 +402,7 @@ static int ajoy_interrupt(int irq, FAR void *context)
int sam_ajoy_initialization(void)
{
int ret;
int fd;
int i;
/* Initialize ADC. We will need this to read the ADC inputs */
@ -416,19 +414,28 @@ int sam_ajoy_initialization(void)
return ret;
}
/* Open the ADC driver for reading.
* REVISIT: This can't work! The file descriptor is only valid in the
* task that opened the file. Not useful for a sharable driver.
*/
/* Open the ADC driver for reading. */
g_adcfd = open("/dev/adc0", O_RDONLY);
if (g_adcfd < 0)
fd = open("/dev/adc0", O_RDONLY);
if (fd < 0)
{
int errcode = get_errno();
idbg("ERROR: Failed to open /dev/adc0: %d\n", errcode);
return -errcode;
}
/* Detach the file structure from the file descriptor so that it can be
* used on any thread.
*/
ret = file_detach(fd, &g_adcfile);
if (ret < 0)
{
idbg("ERROR: Failed to detach from file descriptor: %d\n", ret);
(void)close(fd);
return ret;
}
/* Configure the GPIO pins as interrupting inputs. */
for (i = 0; i < AJOY_NGPIOS; i++)
@ -452,8 +459,7 @@ int sam_ajoy_initialization(void)
if (ret < 0)
{
idbg("ERROR: ajoy_register failed: %d\n", ret);
close(g_adcfd);
g_adcfd = -1;
file_close_detached(&g_adcfile);
}
return ret;

2
fs/inode/Make.defs
View File

@ -39,7 +39,7 @@ ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
CSRCS += fs_files.c fs_foreachinode.c fs_inode.c fs_inodeaddref.c
CSRCS += fs_inodebasename.c fs_inodefind.c fs_inoderelease.c
CSRCS += fs_inoderemove.c fs_inodereserve.c
CSRCS += fs_inoderemove.c fs_inodereserve.c fs_filedetach.c
# Include inode/utils build support

217
fs/inode/fs_filedetach.c Normal file
View File

@ -0,0 +1,217 @@
/****************************************************************************
* fs/inode/fs_filedetach.c
*
* Copyright (C) 2016 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 <semaphore.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/sched.h>
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: _files_semtake
****************************************************************************/
static inline void _files_semtake(FAR struct filelist *list)
{
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&list->fl_sem) != 0)
{
/* The only case that an error should occur here is if
* the wait was awakened by a signal.
*/
DEBUGASSERT(get_errno() == EINTR);
}
}
/****************************************************************************
* Name: _files_semgive
****************************************************************************/
#define _files_semgive(list) sem_post(&list->fl_sem)
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: file_detach
*
* Description:
* This function is used to device drivers to create a task-independent
* handle to an entity in the file system. file_detach() duplicates the
* 'struct file' that underlies the file descriptor, then closes the file
* descriptor.
*
* This function will fail if fd is not a valid file descriptor. In
* particular, it will fail if fd is a socket descriptor.
*
* Input Parameters:
* fd - The file descriptor to be detached. This descriptor will be
* closed and invalid if the file was successfully detached.
* filep - A pointer to a user provided memory location in which to
* received the duplicated, detached file structure.
*
* Returned Value:
* Zero (OK) is returned on success; A negated errno value is returned on
* any failure to indicate the nature of the failure.
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int file_detach(int fd, FAR struct file *filep)
{
FAR struct filelist *list;
FAR struct file *parent;
/* Verify the file descriptor range */
if (fd < 0 || fd >= CONFIG_NFILE_DESCRIPTORS)
{
/* Not a file descriptor (might be a socket descriptor) */
return -EBADF;
}
/* Get the thread-specific file list. It should never be NULL in this
* context.
*/
list = sched_getfiles();
DEBUGASSERT(list != NULL);
/* If the file was properly opened, there should be an inode assigned */
_files_semtake(list);
parent = &list->fl_files[fd];
if (parent->f_inode == NULL)
{
/* File is not open */
_files_semgive(list);
return -EBADF;
}
/* Duplicate the 'struct file' content into the user-provided file
* structure.
*/
filep->f_oflags = parent->f_oflags;
filep->f_pos = parent->f_pos;
filep->f_inode = parent->f_inode;
filep->f_priv = parent->f_priv;
/* Release the file descriptore *without* calling the drive close method
* and without decrementing the inode reference count. That will be done
* in file_close_detached().
*/
parent->f_oflags = 0;
parent->f_pos = 0;
parent->f_inode = NULL;
parent->f_priv = NULL;
_files_semgive(list);
return OK;
}
#endif
/****************************************************************************
* Name: file_close_detached
*
* Description:
* Close a file that was previously detached with file_detach().
*
* REVISIT: This is essentially the same as _files_close()
*
* Input Parameters:
* filep - A pointer to a user provided memory location containing the
* open file data returned by file_detach().
*
* Returned Value:
* Zero (OK) is returned on success; A negated errno value is returned on
* any failure to indicate the nature of the failure.
*
****************************************************************************/
int file_close_detached(FAR struct file *filep)
{
struct inode *inode;
int ret = OK;
DEBUGASSERT(filep != NULL);
inode = filep->f_inode;
/* Check if the struct file is open (i.e., assigned an inode) */
if (inode)
{
/* Close the file, driver, or mountpoint. */
if (inode->u.i_ops && inode->u.i_ops->close)
{
/* Perform the close operation */
ret = inode->u.i_ops->close(filep);
}
/* And release the inode */
inode_release(inode);
/* Reset the user file struct instance so that it cannot be reused. */
filep->f_oflags = 0;
filep->f_pos = 0;
filep->f_inode = NULL;
filep->f_priv = NULL;
}
return ret;
}

8
fs/inode/fs_files.c
View File

@ -65,7 +65,7 @@ static void _files_semtake(FAR struct filelist *list)
while (sem_wait(&list->fl_sem) != 0)
{
/* The only case that an error should occr here is if
/* The only case that an error should occur here is if
* the wait was awakened by a signal.
*/
@ -362,9 +362,9 @@ int files_close(int fd)
/* If the file was properly opened, there should be an inode assigned */
if (fd < 0 || fd >= CONFIG_NFILE_DESCRIPTORS || !list->fl_files[fd].f_inode)
{
return -EBADF;
}
{
return -EBADF;
}
/* Perform the protected close operation */

2
fs/vfs/fs_close.c
View File

@ -105,7 +105,7 @@ int close(int fd)
#if CONFIG_NFILE_DESCRIPTORS > 0
/* Close the driver or mountpoint. NOTES: (1) there is no
* exclusion mechanism here , the driver or mountpoint must be
* exclusion mechanism here, the driver or mountpoint must be
* able to handle concurrent operations internally, (2) The driver
* may have been opened numerous times (for different file
* descriptors) and must also handle being closed numerous times.

48
include/nuttx/fs/fs.h
View File

@ -532,7 +532,7 @@ int file_dup2(FAR struct file *filep1, FAR struct file *filep2);
* function IS dup().
*
* This alternative naming is used when dup could operate on both file and
* socket descritors to avoid drawing unused socket support into the link.
* socket descriptors to avoid drawing unused socket support into the link.
*
****************************************************************************/
@ -574,6 +574,52 @@ int fs_dupfd2(int fd1, int fd2);
#endif
#endif
/****************************************************************************
* Name: file_detach
*
* Description:
* This function is used to device drivers to create a task-independent
* handle to an entity in the file system. file_detach() duplicates the
* 'struct file' that underlies the file descriptor, then closes the file
* descriptor.
*
* This function will fail if fd is not a valid file descriptor. In
* particular, it will fail if fd is a socket descriptor.
*
* Input Parameters:
* fd - The file descriptor to be detached. This descriptor will be
* closed and invalid if the file was successfully detached.
* filep - A pointer to a user provided memory location in which to
* received the duplicated, detached file structure.
*
* Returned Value:
* Zero (OK) is returned on success; A negated errno value is returned on
* any failure to indicate the nature of the failure.
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int file_detach(int fd, FAR struct file *filep);
#endif
/****************************************************************************
* Name: file_close_detached
*
* Description:
* Close a file that was previously detached with file_detach().
*
* Input Parameters:
* filep - A pointer to a user provided memory location containing the
* open file data returned by file_detach().
*
* Returned Value:
* Zero (OK) is returned on success; A negated errno value is returned on
* any failure to indicate the nature of the failure.
*
****************************************************************************/
int file_close_detached(FAR struct file *filep);
/****************************************************************************
* Name: open_blockdriver
*