Pipes

Pipes. More...

Data Structures
struct	pipe_private_t

Functions
static uint64_t	pipe_open (file_t *file)
static uint64_t	pipe_open2 (file_t *files[2])
static void	pipe_close (file_t *file)
static uint64_t	pipe_read (file_t *file, void *buffer, uint64_t count, uint64_t *offset)
static uint64_t	pipe_write (file_t *file, const void *buffer, uint64_t count, uint64_t *offset)
static wait_queue_t *	pipe_poll (file_t *file, poll_events_t *revents)
uint64_t	pipe_init (void)
void	pipe_deinit (void)

Variables
static dentry_t *	pipeDir = NULL
static dentry_t *	newFile = NULL
static file_ops_t	fileOps

Detailed Description

Pipes.

Pipes are exposed in the /dev/pipe directory. Pipes are unidirectional communication channels that can be used for inter-process communication (IPC).

Creating Pipes

Pipes are created using the /dev/pipe/new file. Opening this file using open() will return one file descriptor that can be used for both reading and writing. To create a pipe with separate file descriptors for reading and writing, use open2() with the /dev/pipe/new file.

Using Pipes

Pipes can be read from and written to using the expected read() and write() system calls. Pipes are blocking and pollable, following expected POSIX semantics.

Function Documentation

pipe_close()

static void pipe_close ( file_t *  file )

static

Definition at line 106 of file pipe.c.

References EOK, file, free(), lock_acquire(), lock_release(), pmm_free(), dentry_t::private, WAIT_ALL, wait_queue_deinit(), and wait_unblock().

pipe_deinit()

void pipe_deinit

(

void

)

Definition at line 259 of file pipe.c.

References DEREF, newFile, NULL, and pipeDir.

Referenced by _module_procedure().

pipe_init()

uint64_t pipe_init

(

void

)

Definition at line 239 of file pipe.c.

References DEREF, ERR, fileOps, LOG_ERR, newFile, NULL, pipeDir, sysfs_dir_new(), and sysfs_file_new().

Referenced by _module_procedure().

pipe_open()

static uint64_t pipe_open ( file_t *  file )

static

Definition at line 53 of file pipe.c.

References ERR, file, free(), lock_init(), malloc(), NULL, PAGE_SIZE, pmm_alloc(), dentry_t::private, ring_init(), and wait_queue_init().

pipe_open2()

static uint64_t pipe_open2 ( file_t *  files[2] )

static

Definition at line 79 of file pipe.c.

References ERR, files, free(), lock_init(), malloc(), NULL, PAGE_SIZE, PIPE_READ, PIPE_WRITE, pmm_alloc(), ring_init(), and wait_queue_init().

pipe_poll()

static wait_queue_t * pipe_poll ( file_t *  file, poll_events_t *  revents  )

static

Definition at line 213 of file pipe.c.

References file, LOCK_SCOPE, POLLIN, POLLOUT, dentry_t::private, ring_data_length(), and ring_free_length().

pipe_read()

static uint64_t pipe_read ( file_t *  file, void *  buffer, uint64_t  count, uint64_t *  offset  )

static

Definition at line 132 of file pipe.c.

References buffer, count, EINVAL, ENOTSUP, EOK, ERR, errno, file, LOCK_SCOPE, MIN, NULL, PAGE_SIZE, panic(), dentry_t::private, ring_data_length(), ring_read(), WAIT_ALL, WAIT_BLOCK_LOCK, and wait_unblock().

pipe_write()

static uint64_t pipe_write ( file_t *  file, const void *  buffer, uint64_t  count, uint64_t *  offset  )

static

Definition at line 172 of file pipe.c.

References buffer, count, EINVAL, ENOTSUP, EOK, EPIPE, ERR, errno, file, LOCK_SCOPE, NULL, PAGE_SIZE, panic(), dentry_t::private, ring_free_length(), ring_write(), WAIT_ALL, WAIT_BLOCK_LOCK, and wait_unblock().

Variable Documentation

fileOps

file_ops_t fileOps

static

Initial value:

= {
    .open = pipe_open,
    .open2 = pipe_open2,
    .close = pipe_close,
    .read = pipe_read,
    .write = pipe_write,
    .poll = pipe_poll,
}

Definition at line 230 of file pipe.c.

Referenced by pipe_init().

newFile

dentry_t* newFile = NULL

static

Definition at line 51 of file pipe.c.

Referenced by pipe_deinit(), and pipe_init().

pipeDir

dentry_t* pipeDir = NULL

static

Definition at line 50 of file pipe.c.

Referenced by pipe_deinit(), and pipe_init().