Zephyr API Documentation 3.7.99
A Scalable Open Source RTOS
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Data Structures | |
struct | k_pipe |
Pipe Structure. More... | |
Macros | |
#define | K_PIPE_DEFINE(name, pipe_buffer_size, pipe_align) |
Statically define and initialize a pipe. | |
Functions | |
void | k_pipe_init (struct k_pipe *pipe, unsigned char *buffer, size_t size) |
Initialize a pipe. | |
int | k_pipe_cleanup (struct k_pipe *pipe) |
Release a pipe's allocated buffer. | |
int | k_pipe_alloc_init (struct k_pipe *pipe, size_t size) |
Initialize a pipe and allocate a buffer for it. | |
int | k_pipe_put (struct k_pipe *pipe, const void *data, size_t bytes_to_write, size_t *bytes_written, size_t min_xfer, k_timeout_t timeout) |
Write data to a pipe. | |
int | k_pipe_get (struct k_pipe *pipe, void *data, size_t bytes_to_read, size_t *bytes_read, size_t min_xfer, k_timeout_t timeout) |
Read data from a pipe. | |
size_t | k_pipe_read_avail (struct k_pipe *pipe) |
Query the number of bytes that may be read from pipe. | |
size_t | k_pipe_write_avail (struct k_pipe *pipe) |
Query the number of bytes that may be written to pipe. | |
void | k_pipe_flush (struct k_pipe *pipe) |
Flush the pipe of write data. | |
void | k_pipe_buffer_flush (struct k_pipe *pipe) |
Flush the pipe's internal buffer. | |
#define K_PIPE_DEFINE | ( | name, | |
pipe_buffer_size, | |||
pipe_align ) |
#include <zephyr/kernel.h>
Statically define and initialize a pipe.
The pipe can be accessed outside the module where it is defined using:
name | Name of the pipe. |
pipe_buffer_size | Size of the pipe's ring buffer (in bytes), or zero if no ring buffer is used. |
pipe_align | Alignment of the pipe's ring buffer (power of 2). |
#include <zephyr/kernel.h>
Initialize a pipe and allocate a buffer for it.
Storage for the buffer region will be allocated from the calling thread's resource pool. This memory will be released if k_pipe_cleanup() is called, or userspace is enabled and the pipe object loses all references to it.
This function should only be called on uninitialized pipe objects.
pipe | Address of the pipe. |
size | Size of the pipe's ring buffer (in bytes), or zero if no ring buffer is used. |
0 | on success |
-ENOMEM | if memory couldn't be allocated |
void k_pipe_buffer_flush | ( | struct k_pipe * | pipe | ) |
#include <zephyr/kernel.h>
Flush the pipe's internal buffer.
This routine flushes the pipe's internal buffer. This is equivalent to reading up to N bytes from the pipe (where N is the size of the pipe's buffer) into a temporary buffer and then discarding that buffer. If there were writers previously pending, then some may unpend as they try to fill up the pipe's emptied buffer.
pipe | Address of the pipe. |
int k_pipe_cleanup | ( | struct k_pipe * | pipe | ) |
#include <zephyr/kernel.h>
Release a pipe's allocated buffer.
If a pipe object was given a dynamically allocated buffer via k_pipe_alloc_init(), this will free it. This function does nothing if the buffer wasn't dynamically allocated.
pipe | Address of the pipe. |
0 | on success |
-EAGAIN | nothing to cleanup |
void k_pipe_flush | ( | struct k_pipe * | pipe | ) |
#include <zephyr/kernel.h>
Flush the pipe of write data.
This routine flushes the pipe. Flushing the pipe is equivalent to reading both all the data in the pipe's buffer and all the data waiting to go into that pipe into a large temporary buffer and discarding the buffer. Any writers that were previously pended become unpended.
pipe | Address of the pipe. |
int k_pipe_get | ( | struct k_pipe * | pipe, |
void * | data, | ||
size_t | bytes_to_read, | ||
size_t * | bytes_read, | ||
size_t | min_xfer, | ||
k_timeout_t | timeout ) |
#include <zephyr/kernel.h>
Read data from a pipe.
This routine reads up to bytes_to_read bytes of data from pipe.
pipe | Address of the pipe. |
data | Address to place the data read from pipe. |
bytes_to_read | Maximum number of data bytes to read. |
bytes_read | Address of area to hold the number of bytes read. |
min_xfer | Minimum number of data bytes to read. |
timeout | Waiting period to wait for the data to be read, or one of the special values K_NO_WAIT and K_FOREVER. |
0 | At least min_xfer bytes of data were read. |
-EINVAL | invalid parameters supplied |
-EIO | Returned without waiting; zero data bytes were read. |
-EAGAIN | Waiting period timed out; between zero and min_xfer minus one data bytes were read. |
#include <zephyr/kernel.h>
Initialize a pipe.
This routine initializes a pipe object, prior to its first use.
pipe | Address of the pipe. |
buffer | Address of the pipe's ring buffer, or NULL if no ring buffer is used. |
size | Size of the pipe's ring buffer (in bytes), or zero if no ring buffer is used. |
int k_pipe_put | ( | struct k_pipe * | pipe, |
const void * | data, | ||
size_t | bytes_to_write, | ||
size_t * | bytes_written, | ||
size_t | min_xfer, | ||
k_timeout_t | timeout ) |
#include <zephyr/kernel.h>
Write data to a pipe.
This routine writes up to bytes_to_write bytes of data to pipe.
pipe | Address of the pipe. |
data | Address of data to write. |
bytes_to_write | Size of data (in bytes). |
bytes_written | Address of area to hold the number of bytes written. |
min_xfer | Minimum number of bytes to write. |
timeout | Waiting period to wait for the data to be written, or one of the special values K_NO_WAIT and K_FOREVER. |
0 | At least min_xfer bytes of data were written. |
-EIO | Returned without waiting; zero data bytes were written. |
-EAGAIN | Waiting period timed out; between zero and min_xfer minus one data bytes were written. |
#include <zephyr/kernel.h>
Query the number of bytes that may be read from pipe.
pipe | Address of the pipe. |
a | number n such that 0 <= n <= k_pipe::size; the result is zero for unbuffered pipes. |
#include <zephyr/kernel.h>
Query the number of bytes that may be written to pipe.
pipe | Address of the pipe. |
a | number n such that 0 <= n <= k_pipe::size; the result is zero for unbuffered pipes. |