pipe.c File Reference

BIO abstractions for in-memory pipes. More...

#include <freeradius-devel/bio/bio_priv.h>
#include <freeradius-devel/bio/null.h>
#include <freeradius-devel/bio/buf.h>
#include <freeradius-devel/bio/pipe.h>
#include <pthread.h>

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Data Structures
struct	fr_bio_pipe_t
	The pipe bio. More...

Functions
fr_bio_t *	fr_bio_pipe_alloc (TALLOC_CTX *ctx, fr_bio_cb_funcs_t *cb, size_t buffer_size)
	Allocate a thread-safe pipe which can be used for both reads and writes.
static int	fr_bio_pipe_destructor (fr_bio_pipe_t *my)
static int	fr_bio_pipe_eof (fr_bio_t *bio)
	Set EOF.
static ssize_t	fr_bio_pipe_read (fr_bio_t *bio, UNUSED void *packet_ctx, void *buffer, size_t size)
	Read from the pipe.
static int	fr_bio_pipe_shutdown (fr_bio_t *bio)
	Shutdown callback.
static ssize_t	fr_bio_pipe_shutdown_write (UNUSED fr_bio_t *bio, UNUSED void *packet_ctx, UNUSED void const *buffer, UNUSED size_t size)
static ssize_t	fr_bio_pipe_write (fr_bio_t *bio, UNUSED void *packet_ctx, void const *buffer, size_t size)
	Write to the pipe.

Detailed Description

BIO abstractions for in-memory pipes.

Id

866b58413c8bea7c60889b07e474542a85b47c22

Copyright

2024 Network RADIUS SAS (legal.nosp@m.@net.nosp@m.workr.nosp@m.adiu.nosp@m.s.com)

Definition in file pipe.c.

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Data Structure Documentation

fr_bio_pipe_t

struct fr_bio_pipe_t

The pipe bio.

Definition at line 35 of file pipe.c.

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Data Fields
fr_bio_buf_t	buf	for reading and writing
bool	eof	are we at EOF?
	FR_BIO_COMMON
pthread_mutex_t	mutex

Function Documentation

fr_bio_pipe_alloc()

fr_bio_t * fr_bio_pipe_alloc	(	TALLOC_CTX *	ctx,
		fr_bio_cb_funcs_t *	cb,
		size_t	buffer_size
	)

Allocate a thread-safe pipe which can be used for both reads and writes.

Due to talloc issues with multiple threads, if the caller wants a bi-directional pipe, this function will need to be called twice. That way a free in each context won't result in a race condition on two mutex locks.

For now, it's too difficult to emulate the pipe[2] behavior, where two identical "connected" things are returned, and either can be used for reading or for writing.

i.e. a pipe is really a mutex-protected memory buffer. One side should call write (and never read). The other side should call read (and never write).

The pipe should be freed only after both ends have set EOF.

Definition at line 187 of file pipe.c.

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fr_bio_pipe_destructor()

static int fr_bio_pipe_destructor ( fr_bio_pipe_t *  my )

static

Definition at line 46 of file pipe.c.

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fr_bio_pipe_eof()

static int fr_bio_pipe_eof ( fr_bio_t *  bio )

static

Set EOF.

Either side can set EOF, in which case pending reads are still processed. Writes return EOF immediately. Readers return pending data, and then EOF.

Definition at line 146 of file pipe.c.

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fr_bio_pipe_read()

static ssize_t fr_bio_pipe_read ( fr_bio_t *  bio, UNUSED void *  packet_ctx, void *  buffer, size_t  size  )

static

Read from the pipe.

Once EOF is set, any pending data is read, and then EOF is returned.

Definition at line 59 of file pipe.c.

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fr_bio_pipe_shutdown()

static int fr_bio_pipe_shutdown ( fr_bio_t *  bio )

static

Shutdown callback.

We just set the EOF flag, which means that the other end stops using it. fr_bio_shutdown() mangles the read and write callbacks, so we don't need to do that here.

Definition at line 124 of file pipe.c.

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fr_bio_pipe_shutdown_write()

static ssize_t fr_bio_pipe_shutdown_write ( UNUSED fr_bio_t *  bio, UNUSED void *  packet_ctx, UNUSED void const *  buffer, UNUSED size_t  size  )

static

Definition at line 135 of file pipe.c.

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fr_bio_pipe_write()

static ssize_t fr_bio_pipe_write ( fr_bio_t *  bio, UNUSED void *  packet_ctx, void const *  buffer, size_t  size  )

static

Write to the pipe.

Once EOF is set, no further writes are possible.

Definition at line 95 of file pipe.c.

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