libxcb/src/xcb_conn.c

337 lines
8.5 KiB
C

/* Copyright (C) 2001-2004 Bart Massey and Jamey Sharp.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the names of the authors or their
* institutions shall not be used in advertising or otherwise to promote the
* sale, use or other dealings in this Software without prior written
* authorization from the authors.
*/
/* Connection management: the core of XCB. */
#include <assert.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <sys/select.h>
#include <fcntl.h>
#include <errno.h>
#include "xcb.h"
#include "xcbint.h"
typedef struct {
uint8_t status;
uint8_t pad0[5];
uint16_t length;
} xcb_setup_generic_t;
static const int error_connection = 1;
static int set_fd_flags(const int fd)
{
int flags = fcntl(fd, F_GETFL, 0);
if(flags == -1)
return 0;
flags |= O_NONBLOCK;
if(fcntl(fd, F_SETFL, flags) == -1)
return 0;
if(fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
return 0;
return 1;
}
static int _xcb_xlib_init(_xcb_xlib *xlib)
{
xlib->lock = 0;
pthread_cond_init(&xlib->cond, 0);
return 1;
}
static void _xcb_xlib_destroy(_xcb_xlib *xlib)
{
pthread_cond_destroy(&xlib->cond);
}
static int write_setup(xcb_connection_t *c, xcb_auth_info_t *auth_info)
{
static const char pad[3];
xcb_setup_request_t out;
struct iovec parts[6];
int count = 0;
int endian = 0x01020304;
int ret;
memset(&out, 0, sizeof(out));
/* B = 0x42 = MSB first, l = 0x6c = LSB first */
if(htonl(endian) == endian)
out.byte_order = 0x42;
else
out.byte_order = 0x6c;
out.protocol_major_version = X_PROTOCOL;
out.protocol_minor_version = X_PROTOCOL_REVISION;
out.authorization_protocol_name_len = 0;
out.authorization_protocol_data_len = 0;
parts[count].iov_len = sizeof(xcb_setup_request_t);
parts[count++].iov_base = &out;
parts[count].iov_len = XCB_PAD(sizeof(xcb_setup_request_t));
parts[count++].iov_base = (char *) pad;
if(auth_info)
{
parts[count].iov_len = out.authorization_protocol_name_len = auth_info->namelen;
parts[count++].iov_base = auth_info->name;
parts[count].iov_len = XCB_PAD(out.authorization_protocol_name_len);
parts[count++].iov_base = (char *) pad;
parts[count].iov_len = out.authorization_protocol_data_len = auth_info->datalen;
parts[count++].iov_base = auth_info->data;
parts[count].iov_len = XCB_PAD(out.authorization_protocol_data_len);
parts[count++].iov_base = (char *) pad;
}
assert(count <= sizeof(parts) / sizeof(*parts));
_xcb_lock_io(c);
{
struct iovec *parts_ptr = parts;
ret = _xcb_out_send(c, &parts_ptr, &count);
}
_xcb_unlock_io(c);
return ret;
}
static int read_setup(xcb_connection_t *c)
{
/* Read the server response */
c->setup = malloc(sizeof(xcb_setup_generic_t));
if(!c->setup)
return 0;
if(_xcb_in_read_block(c, c->setup, sizeof(xcb_setup_generic_t)) != sizeof(xcb_setup_generic_t))
return 0;
{
void *tmp = realloc(c->setup, c->setup->length * 4 + sizeof(xcb_setup_generic_t));
if(!tmp)
return 0;
c->setup = tmp;
}
if(_xcb_in_read_block(c, (char *) c->setup + sizeof(xcb_setup_generic_t), c->setup->length * 4) <= 0)
return 0;
/* 0 = failed, 2 = authenticate, 1 = success */
switch(c->setup->status)
{
case 0: /* failed */
{
xcb_setup_failed_t *setup = (xcb_setup_failed_t *) c->setup;
write(STDERR_FILENO, xcb_setup_failed_reason(setup), xcb_setup_failed_reason_length(setup));
return 0;
}
case 2: /* authenticate */
{
xcb_setup_authenticate_t *setup = (xcb_setup_authenticate_t *) c->setup;
write(STDERR_FILENO, xcb_setup_authenticate_reason(setup), xcb_setup_authenticate_reason_length(setup));
return 0;
}
}
return 1;
}
/* precondition: there must be something for us to write. */
static int write_vec(xcb_connection_t *c, struct iovec **vector, int *count)
{
int n;
assert(!c->out.queue_len);
n = writev(c->fd, *vector, *count);
if(n < 0 && errno == EAGAIN)
return 1;
if(n <= 0)
{
_xcb_conn_shutdown(c);
return 0;
}
for(; *count; --*count, ++*vector)
{
int cur = (*vector)->iov_len;
if(cur > n)
cur = n;
(*vector)->iov_len -= cur;
(*vector)->iov_base = (char *) (*vector)->iov_base + cur;
n -= cur;
if((*vector)->iov_len)
break;
}
if(!*count)
*vector = 0;
assert(n == 0);
return 1;
}
/* Public interface */
const xcb_setup_t *xcb_get_setup(xcb_connection_t *c)
{
if(c->has_error)
return 0;
/* doesn't need locking because it's never written to. */
return c->setup;
}
int xcb_get_file_descriptor(xcb_connection_t *c)
{
if(c->has_error)
return -1;
/* doesn't need locking because it's never written to. */
return c->fd;
}
int xcb_connection_has_error(xcb_connection_t *c)
{
/* doesn't need locking because it's read and written atomically. */
return c->has_error;
}
xcb_connection_t *xcb_connect_to_fd(int fd, xcb_auth_info_t *auth_info)
{
xcb_connection_t* c;
c = calloc(1, sizeof(xcb_connection_t));
if(!c)
return (xcb_connection_t *) &error_connection;
c->fd = fd;
if(!(
set_fd_flags(fd) &&
pthread_mutex_init(&c->iolock, 0) == 0 &&
_xcb_xlib_init(&c->xlib) &&
_xcb_in_init(&c->in) &&
_xcb_out_init(&c->out) &&
write_setup(c, auth_info) &&
read_setup(c) &&
_xcb_ext_init(c) &&
_xcb_xid_init(c)
))
{
xcb_disconnect(c);
return (xcb_connection_t *) &error_connection;
}
return c;
}
void xcb_disconnect(xcb_connection_t *c)
{
if(c->has_error)
return;
free(c->setup);
close(c->fd);
pthread_mutex_destroy(&c->iolock);
_xcb_xlib_destroy(&c->xlib);
_xcb_in_destroy(&c->in);
_xcb_out_destroy(&c->out);
_xcb_ext_destroy(c);
_xcb_xid_destroy(c);
free(c);
}
/* Private interface */
void _xcb_conn_shutdown(xcb_connection_t *c)
{
c->has_error = 1;
}
void _xcb_lock_io(xcb_connection_t *c)
{
pthread_mutex_lock(&c->iolock);
while(c->xlib.lock)
{
if(pthread_equal(c->xlib.thread, pthread_self()))
break;
pthread_cond_wait(&c->xlib.cond, &c->iolock);
}
}
void _xcb_unlock_io(xcb_connection_t *c)
{
pthread_mutex_unlock(&c->iolock);
}
int _xcb_conn_wait(xcb_connection_t *c, pthread_cond_t *cond, struct iovec **vector, int *count)
{
int ret;
fd_set rfds, wfds;
/* If the thing I should be doing is already being done, wait for it. */
if(count ? c->out.writing : c->in.reading)
{
pthread_cond_wait(cond, &c->iolock);
return 1;
}
FD_ZERO(&rfds);
FD_SET(c->fd, &rfds);
++c->in.reading;
FD_ZERO(&wfds);
if(count)
{
FD_SET(c->fd, &wfds);
++c->out.writing;
}
_xcb_unlock_io(c);
do {
ret = select(c->fd + 1, &rfds, &wfds, 0, 0);
} while (ret == -1 && errno == EINTR);
if (ret < 0)
{
_xcb_conn_shutdown(c);
ret = 0;
}
_xcb_lock_io(c);
if(ret)
{
if(FD_ISSET(c->fd, &rfds))
ret = ret && _xcb_in_read(c);
if(FD_ISSET(c->fd, &wfds))
ret = ret && write_vec(c, vector, count);
}
if(count)
--c->out.writing;
--c->in.reading;
return ret;
}