Sweden-Number/server/pipe.c

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/*
* Server-side pipe management
*
* Copyright (C) 1998 Alexandre Julliard
*/
#include <assert.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include "winerror.h"
#include "winbase.h"
#include "server/thread.h"
enum side { READ_SIDE, WRITE_SIDE };
struct pipe
{
struct object obj; /* object header */
struct pipe *other; /* the pipe other end */
int fd; /* Unix file descriptor */
enum side side; /* which side of the pipe is this */
};
static void pipe_dump( struct object *obj, int verbose );
static int pipe_add_queue( struct object *obj, struct wait_queue_entry *entry );
static void pipe_remove_queue( struct object *obj, struct wait_queue_entry *entry );
static int pipe_signaled( struct object *obj, struct thread *thread );
static int pipe_get_read_fd( struct object *obj );
static int pipe_get_write_fd( struct object *obj );
static int pipe_get_info( struct object *obj, struct get_file_info_reply *reply );
static void pipe_destroy( struct object *obj );
static const struct object_ops pipe_ops =
{
pipe_dump,
pipe_add_queue,
pipe_remove_queue,
pipe_signaled,
no_satisfied,
pipe_get_read_fd,
pipe_get_write_fd,
no_flush,
pipe_get_info,
pipe_destroy
};
static const struct select_ops select_ops =
{
default_select_event,
NULL /* we never set a timeout on a pipe */
};
int create_pipe( struct object *obj[2] )
{
struct pipe *newpipe[2];
int fd[2];
if (pipe( fd ) == -1)
{
file_set_error();
return 0;
}
if (!(newpipe[0] = mem_alloc( sizeof(struct pipe) )))
{
close( fd[0] );
close( fd[1] );
return 0;
}
if (!(newpipe[1] = mem_alloc( sizeof(struct pipe) )))
{
close( fd[0] );
close( fd[1] );
free( newpipe[0] );
return 0;
}
init_object( &newpipe[0]->obj, &pipe_ops, NULL );
init_object( &newpipe[1]->obj, &pipe_ops, NULL );
newpipe[0]->fd = fd[0];
newpipe[0]->other = newpipe[1];
newpipe[0]->side = READ_SIDE;
newpipe[1]->fd = fd[1];
newpipe[1]->other = newpipe[0];
newpipe[1]->side = WRITE_SIDE;
obj[0] = &newpipe[0]->obj;
obj[1] = &newpipe[1]->obj;
CLEAR_ERROR();
return 1;
}
static void pipe_dump( struct object *obj, int verbose )
{
struct pipe *pipe = (struct pipe *)obj;
assert( obj->ops == &pipe_ops );
fprintf( stderr, "Pipe %s-side fd=%d\n",
(pipe->side == READ_SIDE) ? "read" : "write", pipe->fd );
}
static int pipe_add_queue( struct object *obj, struct wait_queue_entry *entry )
{
struct pipe *pipe = (struct pipe *)obj;
assert( obj->ops == &pipe_ops );
if (!obj->head) /* first on the queue */
{
if (!add_select_user( pipe->fd,
(pipe->side == READ_SIDE) ? READ_EVENT : WRITE_EVENT,
&select_ops, pipe ))
{
SET_ERROR( ERROR_OUTOFMEMORY );
return 0;
}
}
add_queue( obj, entry );
return 1;
}
static void pipe_remove_queue( struct object *obj, struct wait_queue_entry *entry )
{
struct pipe *pipe = (struct pipe *)grab_object(obj);
assert( obj->ops == &pipe_ops );
remove_queue( obj, entry );
if (!obj->head) /* last on the queue is gone */
remove_select_user( pipe->fd );
release_object( obj );
}
static int pipe_signaled( struct object *obj, struct thread *thread )
{
struct pipe *pipe = (struct pipe *)obj;
struct timeval tv = { 0, 0 };
fd_set fds;
assert( obj->ops == &pipe_ops );
FD_ZERO( &fds );
FD_SET( pipe->fd, &fds );
if (pipe->side == READ_SIDE)
return select( pipe->fd + 1, &fds, NULL, NULL, &tv ) > 0;
else
return select( pipe->fd + 1, NULL, &fds, NULL, &tv ) > 0;
}
static int pipe_get_read_fd( struct object *obj )
{
struct pipe *pipe = (struct pipe *)obj;
assert( obj->ops == &pipe_ops );
if (!pipe->other)
{
SET_ERROR( ERROR_BROKEN_PIPE );
return -1;
}
if (pipe->side != READ_SIDE) /* FIXME: should not be necessary */
{
SET_ERROR( ERROR_ACCESS_DENIED );
return -1;
}
return dup( pipe->fd );
}
static int pipe_get_write_fd( struct object *obj )
{
struct pipe *pipe = (struct pipe *)obj;
assert( obj->ops == &pipe_ops );
if (!pipe->other)
{
SET_ERROR( ERROR_BROKEN_PIPE );
return -1;
}
if (pipe->side != WRITE_SIDE) /* FIXME: should not be necessary */
{
SET_ERROR( ERROR_ACCESS_DENIED );
return -1;
}
return dup( pipe->fd );
}
static int pipe_get_info( struct object *obj, struct get_file_info_reply *reply )
{
memset( reply, 0, sizeof(*reply) );
reply->type = FILE_TYPE_PIPE;
return 1;
}
static void pipe_destroy( struct object *obj )
{
struct pipe *pipe = (struct pipe *)obj;
assert( obj->ops == &pipe_ops );
if (pipe->other) pipe->other->other = NULL;
close( pipe->fd );
free( pipe );
}