rt-thread-official/components/drivers/ipc/pipe.c

759 lines
18 KiB
C

/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2012-09-30 Bernard first version.
* 2017-11-08 JasonJiaJie fix memory leak issue when close a pipe.
*/
#include <rthw.h>
#include <rtdevice.h>
#include <stdint.h>
#include <sys/errno.h>
#if defined(RT_USING_POSIX_DEVIO) && defined(RT_USING_POSIX_PIPE)
#include <unistd.h>
#include <fcntl.h>
#include <poll.h>
#include <sys/ioctl.h>
#include <dfs_file.h>
/**
* @brief This function will open a pipe.
*
* @param fd is the file descriptor.
*
* @return Return the operation status.
* When the return value is 0, it means the operation is successful.
* When the return value is -1, it means the file descriptor is invalid.
* When the return value is -RT_ENOMEM, it means insufficient memory allocation failed.
*/
static int pipe_fops_open(struct dfs_fd *fd)
{
int rc = 0;
rt_device_t device;
rt_pipe_t *pipe;
pipe = (rt_pipe_t *)fd->data;
if (!pipe) return -1;
device = &(pipe->parent);
rt_mutex_take(&(pipe->lock), RT_WAITING_FOREVER);
if (device->ref_count == 0)
{
pipe->fifo = rt_ringbuffer_create(pipe->bufsz);
if (pipe->fifo == RT_NULL)
{
rc = -RT_ENOMEM;
goto __exit;
}
}
switch (fd->flags & O_ACCMODE)
{
case O_RDONLY:
pipe->readers ++;
break;
case O_WRONLY:
pipe->writers ++;
break;
case O_RDWR:
pipe->readers ++;
pipe->writers ++;
break;
}
device->ref_count ++;
__exit:
rt_mutex_release(&(pipe->lock));
return rc;
}
/**
* @brief This function will close a pipe.
*
* @param fd is the file descriptor.
*
* @return Return the operation status.
* When the return value is 0, it means the operation is successful.
* When the return value is -1, it means the file descriptor is invalid.
*/
static int pipe_fops_close(struct dfs_fd *fd)
{
rt_device_t device;
rt_pipe_t *pipe;
pipe = (rt_pipe_t *)fd->data;
if (!pipe) return -1;
device = &(pipe->parent);
rt_mutex_take(&(pipe->lock), RT_WAITING_FOREVER);
switch (fd->flags & O_ACCMODE)
{
case O_RDONLY:
pipe->readers --;
break;
case O_WRONLY:
pipe->writers --;
break;
case O_RDWR:
pipe->readers --;
pipe->writers --;
break;
}
if (pipe->writers == 0)
{
rt_wqueue_wakeup(&(pipe->reader_queue), (void *)(POLLIN | POLLERR | POLLHUP));
}
if (pipe->readers == 0)
{
rt_wqueue_wakeup(&(pipe->writer_queue), (void *)(POLLOUT | POLLERR | POLLHUP));
}
if (device->ref_count == 1)
{
if (pipe->fifo != RT_NULL)
rt_ringbuffer_destroy(pipe->fifo);
pipe->fifo = RT_NULL;
}
device->ref_count --;
rt_mutex_release(&(pipe->lock));
if (device->ref_count == 0 && pipe->is_named == RT_FALSE)
{
/* delete the unamed pipe */
rt_pipe_delete(device->parent.name);
}
return 0;
}
/**
* @brief This function will get the pipe space size depends on the command.
*
* @param fd is the file descriptor.
*
* @param cmd is the command. It determines what data will get.
*
* FIONREAD The command to get the number of bytes in the pipe.
*
* FIONWRITE The command to get the number of bytes can be written to the pipe.
*
* @param args is the pointer to the data to store the read data.
*
* @return Return the operation status.
* When the return value is 0, it means the operation is successful.
* When the return value is -EINVAL, it means the command is invalid.
*/
static int pipe_fops_ioctl(struct dfs_fd *fd, int cmd, void *args)
{
rt_pipe_t *pipe;
int ret = 0;
pipe = (rt_pipe_t *)fd->data;
switch (cmd)
{
case FIONREAD:
*((int *)args) = rt_ringbuffer_data_len(pipe->fifo);
break;
case FIONWRITE:
*((int *)args) = rt_ringbuffer_space_len(pipe->fifo);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
/**
* @brief This function will read data from pipe.
*
* @param fd is the file descriptor.
*
* @param buf is the buffer to store the read data.
*
* @param count is the length of data to be read.
*
* @return Return the length of data read.
* When the return value is 0, it means O_NONBLOCK is enabled and there is no thread that has the pipe open for writing.
* When the return value is -EAGAIN, it means there are no data to be read.
*/
static int pipe_fops_read(struct dfs_fd *fd, void *buf, size_t count)
{
int len = 0;
rt_pipe_t *pipe;
pipe = (rt_pipe_t *)fd->data;
/* no process has the pipe open for writing, return end-of-file */
if (pipe->writers == 0)
return 0;
rt_mutex_take(&(pipe->lock), RT_WAITING_FOREVER);
while (1)
{
if (pipe->writers == 0)
{
goto out;
}
len = rt_ringbuffer_get(pipe->fifo, buf, count);
if (len > 0)
{
break;
}
else
{
if (fd->flags & O_NONBLOCK)
{
len = -EAGAIN;
goto out;
}
rt_mutex_release(&pipe->lock);
rt_wqueue_wakeup(&(pipe->writer_queue), (void *)POLLOUT);
rt_wqueue_wait(&(pipe->reader_queue), 0, -1);
rt_mutex_take(&(pipe->lock), RT_WAITING_FOREVER);
}
}
/* wakeup writer */
rt_wqueue_wakeup(&(pipe->writer_queue), (void *)POLLOUT);
out:
rt_mutex_release(&pipe->lock);
return len;
}
/**
* @brief This function will write data to pipe.
*
* @param fd is the file descriptor.
*
* @param buf is a pointer to the data buffer to be written.
*
* @param count is the length of data to be write.
*
* @return Return the length of data written.
* When the return value is -EAGAIN, it means O_NONBLOCK is enabled and there are no space to be written.
* When the return value is -EPIPE, it means there is no thread that has the pipe open for reading.
*/
static int pipe_fops_write(struct dfs_fd *fd, const void *buf, size_t count)
{
int len;
rt_pipe_t *pipe;
int wakeup = 0;
int ret = 0;
uint8_t *pbuf;
pipe = (rt_pipe_t *)fd->data;
if (pipe->readers == 0)
{
ret = -EPIPE;
goto out;
}
if (count == 0)
return 0;
pbuf = (uint8_t *)buf;
rt_mutex_take(&pipe->lock, -1);
while (1)
{
if (pipe->readers == 0)
{
if (ret == 0)
ret = -EPIPE;
break;
}
len = rt_ringbuffer_put(pipe->fifo, pbuf, count - ret);
ret += len;
pbuf += len;
wakeup = 1;
if (ret == count)
{
break;
}
else
{
if (fd->flags & O_NONBLOCK)
{
if (ret == 0)
{
ret = -EAGAIN;
}
break;
}
}
rt_mutex_release(&pipe->lock);
rt_wqueue_wakeup(&(pipe->reader_queue), (void *)POLLIN);
/* pipe full, waiting on suspended write list */
rt_wqueue_wait(&(pipe->writer_queue), 0, -1);
rt_mutex_take(&pipe->lock, -1);
}
rt_mutex_release(&pipe->lock);
if (wakeup)
{
rt_wqueue_wakeup(&(pipe->reader_queue), (void *)POLLIN);
}
out:
return ret;
}
/**
* @brief This function will get the pipe status.
*
* @param fd is the file descriptor.
*
* @param req is the request type.
*
* @return mask of the pipe status.
* POLLIN means there is data to be read.
* POLLHUP means there is no thread that occupied the pipe to open for writing.
* POLLOUT means there is space to be written.
* POLLERR means there is no thread that occupied the pipe to open for reading.
*/
static int pipe_fops_poll(struct dfs_fd *fd, rt_pollreq_t *req)
{
int mask = 0;
rt_pipe_t *pipe;
int mode = 0;
pipe = (rt_pipe_t *)fd->data;
rt_poll_add(&(pipe->reader_queue), req);
rt_poll_add(&(pipe->writer_queue), req);
switch (fd->flags & O_ACCMODE)
{
case O_RDONLY:
mode = 1;
break;
case O_WRONLY:
mode = 2;
break;
case O_RDWR:
mode = 3;
break;
}
if (mode & 1)
{
if (rt_ringbuffer_data_len(pipe->fifo) != 0)
{
mask |= POLLIN;
}
if (pipe->writers == 0)
{
mask |= POLLHUP;
}
}
if (mode & 2)
{
if (rt_ringbuffer_space_len(pipe->fifo) != 0)
{
mask |= POLLOUT;
}
if (pipe->readers == 0)
{
mask |= POLLERR;
}
}
return mask;
}
static const struct dfs_file_ops pipe_fops =
{
pipe_fops_open,
pipe_fops_close,
pipe_fops_ioctl,
pipe_fops_read,
pipe_fops_write,
RT_NULL,
RT_NULL,
RT_NULL,
pipe_fops_poll,
};
#endif /* defined(RT_USING_POSIX_DEVIO) && defined(RT_USING_POSIX_PIPE) */
/**
* @brief This function will open the pipe and actually creates the pipe buffer.
*
* @param device is a pointer to the pipe device descriptor.
*
* @param oflag is the open method, but it is not used yet.
*
* @return Return the operation status.
* When the return value is RT_EOK, the operation is successful.
* When the return value is -RT_EINVAL, it means the device handle is empty.
* When the return value is -RT_ENOMEM, it means insufficient memory allocation failed.
*/
static rt_err_t rt_pipe_open(rt_device_t device, rt_uint16_t oflag)
{
rt_pipe_t *pipe = (rt_pipe_t *)device;
rt_err_t ret = RT_EOK;
if (device == RT_NULL)
{
ret = -RT_EINVAL;
goto __exit;
}
rt_mutex_take(&(pipe->lock), RT_WAITING_FOREVER);
if (pipe->fifo == RT_NULL)
{
pipe->fifo = rt_ringbuffer_create(pipe->bufsz);
if (pipe->fifo == RT_NULL)
{
ret = -RT_ENOMEM;
}
}
rt_mutex_release(&(pipe->lock));
__exit:
return ret;
}
/**
* @brief This function will close the pipe and release the pipe buffer.
*
* @param device is a pointer to the pipe device descriptor.
*
* @return Return the operation status.
* When the return value is RT_EOK, the operation is successful.
* When the return value is -RT_EINVAL, it means the device handle is empty.
*/
static rt_err_t rt_pipe_close(rt_device_t device)
{
rt_pipe_t *pipe = (rt_pipe_t *)device;
if (device == RT_NULL) return -RT_EINVAL;
rt_mutex_take(&(pipe->lock), RT_WAITING_FOREVER);
if (device->ref_count == 1)
{
rt_ringbuffer_destroy(pipe->fifo);
pipe->fifo = RT_NULL;
}
rt_mutex_release(&(pipe->lock));
return RT_EOK;
}
/**
* @brief This function will read the specified length of data from the pipe.
*
* @param device is a pointer to the pipe device descriptor.
*
* @param pos is a parameter compatible with POSIX standard interface (currently meaningless, just pass in 0).
*
* @param buffer is a pointer to the buffer to store the read data.
*
* @param count is the length of data to be read.
*
* @return Return the length of data read.
* When the return value is 0, it means the pipe device handle is empty or the count is 0.
*/
static rt_size_t rt_pipe_read(rt_device_t device, rt_off_t pos, void *buffer, rt_size_t count)
{
uint8_t *pbuf;
rt_size_t read_bytes = 0;
rt_pipe_t *pipe = (rt_pipe_t *)device;
if (device == RT_NULL)
{
rt_set_errno(EINVAL);
return 0;
}
if (count == 0) return 0;
pbuf = (uint8_t *)buffer;
rt_mutex_take(&(pipe->lock), RT_WAITING_FOREVER);
while (read_bytes < count)
{
int len = rt_ringbuffer_get(pipe->fifo, &pbuf[read_bytes], count - read_bytes);
if (len <= 0) break;
read_bytes += len;
}
rt_mutex_release(&pipe->lock);
return read_bytes;
}
/**
* @brief This function will write the specified length of data to the pipe.
*
* @param device is a pointer to the pipe device descriptor.
*
* @param pos is a parameter compatible with POSIX standard interface (currently meaningless, just pass in 0).
*
* @param buffer is a pointer to the data buffer to be written.
*
* @param count is the length of data to be written.
*
* @return Return the length of data written.
* When the return value is 0, it means the pipe device handle is empty or the count is 0.
*/
static rt_size_t rt_pipe_write(rt_device_t device, rt_off_t pos, const void *buffer, rt_size_t count)
{
uint8_t *pbuf;
rt_size_t write_bytes = 0;
rt_pipe_t *pipe = (rt_pipe_t *)device;
if (device == RT_NULL)
{
rt_set_errno(EINVAL);
return 0;
}
if (count == 0) return 0;
pbuf = (uint8_t *)buffer;
rt_mutex_take(&pipe->lock, -1);
while (write_bytes < count)
{
int len = rt_ringbuffer_put(pipe->fifo, &pbuf[write_bytes], count - write_bytes);
if (len <= 0) break;
write_bytes += len;
}
rt_mutex_release(&pipe->lock);
return write_bytes;
}
/**
* @brief This function is not used yet.
*
* @param dev is not used yet.
*
* @param cmd is not used yet.
*
* @param args is not used yet.
*
* @return Always return RT_EOK.
*/
static rt_err_t rt_pipe_control(rt_device_t dev, int cmd, void *args)
{
return RT_EOK;
}
#ifdef RT_USING_DEVICE_OPS
const static struct rt_device_ops pipe_ops =
{
RT_NULL,
rt_pipe_open,
rt_pipe_close,
rt_pipe_read,
rt_pipe_write,
rt_pipe_control,
};
#endif /* RT_USING_DEVICE_OPS */
/**
* @brief This function will initialize a pipe device.
* The system allocates a pipe handle from dynamic heap memory, initializes the pipe handle
* with the specified value, and registers the pipe device with the system.
*
* @param name is the name of pipe device.
*
* @param bufsz is the size of pipe buffer.
*
* @return Return the pointer to the pipe device.
* When the return value is RT_NULL, it means the initialization failed.
*/
rt_pipe_t *rt_pipe_create(const char *name, int bufsz)
{
rt_pipe_t *pipe;
rt_device_t dev;
pipe = (rt_pipe_t *)rt_malloc(sizeof(rt_pipe_t));
if (pipe == RT_NULL) return RT_NULL;
rt_memset(pipe, 0, sizeof(rt_pipe_t));
pipe->is_named = RT_TRUE; /* initialize as a named pipe */
rt_mutex_init(&(pipe->lock), name, RT_IPC_FLAG_PRIO);
rt_wqueue_init(&(pipe->reader_queue));
rt_wqueue_init(&(pipe->writer_queue));
RT_ASSERT(bufsz < 0xFFFF);
pipe->bufsz = bufsz;
dev = &(pipe->parent);
dev->type = RT_Device_Class_Pipe;
#ifdef RT_USING_DEVICE_OPS
dev->ops = &pipe_ops;
#else
dev->init = RT_NULL;
dev->open = rt_pipe_open;
dev->read = rt_pipe_read;
dev->write = rt_pipe_write;
dev->close = rt_pipe_close;
dev->control = rt_pipe_control;
#endif
dev->rx_indicate = RT_NULL;
dev->tx_complete = RT_NULL;
if (rt_device_register(&(pipe->parent), name, RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_REMOVABLE) != 0)
{
rt_free(pipe);
return RT_NULL;
}
#if defined(RT_USING_POSIX_DEVIO) && defined(RT_USING_POSIX_PIPE)
dev->fops = (void *)&pipe_fops;
#endif
return pipe;
}
/**
* @brief This function will delete a pipe device.
* The system will release the pipe handle and unregister the pipe device from the system.
*
* @param pipe is the pointer to the pipe device.
*
* @return Return the operation status.
* When the return value is 0, it means the operation is successful.
* When the return value is -RT_EINVAL, it means the pipe device is not found or the device isn't a pipe.
* When the return value is -RT_EBUSY, it means the pipe device is busy.
*/
int rt_pipe_delete(const char *name)
{
int result = 0;
rt_device_t device;
device = rt_device_find(name);
if (device)
{
if (device->type == RT_Device_Class_Pipe)
{
rt_pipe_t *pipe;
if (device->ref_count != 0)
{
return -RT_EBUSY;
}
pipe = (rt_pipe_t *)device;
rt_mutex_detach(&(pipe->lock));
rt_device_unregister(device);
/* close fifo ringbuffer */
if (pipe->fifo)
{
rt_ringbuffer_destroy(pipe->fifo);
pipe->fifo = RT_NULL;
}
rt_free(pipe);
}
else
{
result = -RT_EINVAL;
}
}
else
{
result = -RT_EINVAL;
}
return result;
}
#if defined(RT_USING_POSIX_DEVIO) && defined(RT_USING_POSIX_PIPE)
/**
* @brief This function will creat a anonymous pipe.
*
* @param fildes[0] is the read handle.
* fildes[1] is the write handle.
*
* @return Return the operation status.
* When the return value is 0, it means the operation is successful.
* When the return value is -1, it means the operation is failed.
*/
int pipe(int fildes[2])
{
rt_pipe_t *pipe;
char dname[RT_NAME_MAX];
char dev_name[RT_NAME_MAX * 4];
static int pipeno = 0;
rt_snprintf(dname, sizeof(dname), "pipe%d", pipeno++);
pipe = rt_pipe_create(dname, RT_USING_POSIX_PIPE_SIZE);
if (pipe == RT_NULL)
{
return -1;
}
pipe->is_named = RT_FALSE; /* unamed pipe */
rt_snprintf(dev_name, sizeof(dev_name), "/dev/%s", dname);
fildes[0] = open(dev_name, O_RDONLY, 0);
if (fildes[0] < 0)
{
return -1;
}
fildes[1] = open(dev_name, O_WRONLY, 0);
if (fildes[1] < 0)
{
close(fildes[0]);
return -1;
}
return 0;
}
/**
* @brief This function will create a named pipe.
*
* @param path is the name of pipe device.
*
* @param mode is not used yet.
*
* @return Return the operation status.
* When the return value is 0, it means the operation is successful.
* When the return value is -1, it means the operation is failed.
*/
int mkfifo(const char *path, mode_t mode)
{
rt_pipe_t *pipe;
pipe = rt_pipe_create(path, RT_USING_POSIX_PIPE_SIZE);
if (pipe == RT_NULL)
{
return -1;
}
return 0;
}
#endif /* defined(RT_USING_POSIX_DEVIO) && defined(RT_USING_POSIX_PIPE) */