/* 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;
}
/* 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);
#ifdef _WIN32
int i = 0;
int ret = 0,err = 0;
struct iovec *vec;
n = 0;
/* Could use the WSASend win32 function for scatter/gather i/o but setting up the WSABUF struct from
an iovec would require more work and I'm not sure of the benefit....works for now */
vec = *vector;
while(i < *count)
{
ret = send(c->fd,vec->iov_base,vec->iov_len,0);
if(ret == SOCKET_ERROR)
{
err = WSAGetLastError();
if(err == WSAEWOULDBLOCK)
{
return 1;
}
}
n += ret;
*vec++;
i++;
}
#else
n = writev(c->fd, *vector, *count);
if(n < 0 && errno == EAGAIN)
return 1;
#endif /* _WIN32 */
if(n <= 0)
{
_xcb_conn_shutdown(c, XCB_CONN_ERROR);
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;
}
int _xcb_conn_wait(xcb_connection_t *c, pthread_cond_t *cond, struct iovec **vector, int *count)
{
int ret;
#if USE_POLL
struct pollfd fd;
#else
fd_set rfds, wfds;
#endif
/* 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;
}
#if USE_POLL
memset(&fd, 0, sizeof(fd));
fd.fd = c->fd;
fd.events = POLLIN;
#else
FD_ZERO(&rfds);
FD_SET(c->fd, &rfds);
#endif
++c->in.reading;
#if USE_POLL
if(count)
{
fd.events |= POLLOUT;
++c->out.writing;
}
#else
FD_ZERO(&wfds);
if(count)
{
FD_SET(c->fd, &wfds);
++c->out.writing;
}
#endif
pthread_mutex_unlock(&c->iolock);
do {
#if USE_POLL
ret = poll(&fd, 1, -1);
#else
ret = select(c->fd + 1, &rfds, &wfds, 0, 0);
#endif
} while (ret == -1 && errno == EINTR);
if(ret < 0)
{
_xcb_conn_shutdown(c);
ret = 0;
}
pthread_mutex_lock(&c->iolock);
if(ret)
{
#if USE_POLL
if((fd.revents & POLLIN) == POLLIN)
#else
if(FD_ISSET(c->fd, &rfds))
#endif
ret = ret && _xcb_in_read(c);
#if USE_POLL
if((fd.revents & POLLOUT) == POLLOUT)
#else
if(FD_ISSET(c->fd, &wfds))
#endif
ret = ret && write_vec(c, vector, count);
}
if(count)
--c->out.writing;
--c->in.reading;
return ret;
}
unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vector, const xcb_protocol_request_t *req)
{
uint64_t request;
uint32_t prefix[2];
int veclen = req->count;
enum workarounds workaround = WORKAROUND_NONE;
if(c->has_error)
return 0;
assert(c != 0);
assert(vector != 0);
assert(req->count > 0);
if(!(flags & XCB_REQUEST_RAW))
{
static const char pad[3];
unsigned int i;
uint16_t shortlen = 0;
size_t longlen = 0;
assert(vector[0].iov_len >= 4);
/* set the major opcode, and the minor opcode for extensions */
if(req->ext)
{
const xcb_query_extension_reply_t *extension = xcb_get_extension_data(c, req->ext);
if(!(extension && extension->present))
{
_xcb_conn_shutdown(c, XCB_CONN_CLOSED_EXT_NOTSUPPORTED);
return 0;
}
((uint8_t *) vector[0].iov_base)[0] = extension->major_opcode;
((uint8_t *) vector[0].iov_base)[1] = req->opcode;
}
else
((uint8_t *) vector[0].iov_base)[0] = req->opcode;
/* put together the length field, possibly using BIGREQUESTS */
for(i = 0; i < req->count; ++i)
{
longlen += vector[i].iov_len;
if(!vector[i].iov_base)
{
vector[i].iov_base = (char *) pad;
assert(vector[i].iov_len <= sizeof(pad));
}
}
assert((longlen & 3) == 0);
longlen >>= 2;
if(longlen <= c->setup->maximum_request_length)
{
/* we don't need BIGREQUESTS. */
shortlen = longlen;
longlen = 0;
}
else if(longlen > xcb_get_maximum_request_length(c))
{
_xcb_conn_shutdown(c, XCB_CONN_CLOSED_REQ_LEN_EXCEED);
return 0; /* server can't take this; maybe need BIGREQUESTS? */
}
/* set the length field. */
((uint16_t *) vector[0].iov_base)[1] = shortlen;
if(!shortlen)
{
prefix[0] = ((uint32_t *) vector[0].iov_base)[0];
prefix[1] = ++longlen;
vector[0].iov_base = (uint32_t *) vector[0].iov_base + 1;
vector[0].iov_len -= sizeof(uint32_t);
--vector, ++veclen;
vector[0].iov_base = prefix;
vector[0].iov_len = sizeof(prefix);
}
}
flags &= ~XCB_REQUEST_RAW;
/* do we need to work around the X server bug described in glx.xml? */
/* XXX: GetFBConfigs won't use BIG-REQUESTS in any sane
* configuration, but that should be handled here anyway. */
if(req->ext && !req->isvoid && !strcmp(req->ext->name, "GLX") &&
((req->opcode == 17 && ((uint32_t *) vector[0].iov_base)[1] == 0x10004) ||
req->opcode == 21))
workaround = WORKAROUND_GLX_GET_FB_CONFIGS_BUG;
/* get a sequence number and arrange for delivery. */
pthread_mutex_lock(&c->iolock);
/* wait for other writing threads to get out of my way. */
while(c->out.writing)
pthread_cond_wait(&c->out.cond, &c->iolock);
get_socket_back(c);
/* send GetInputFocus (sync_req) when 64k-2 requests have been sent without
* a reply. */
if(req->isvoid && c->out.request == c->in.request_expected + (1 << 16) - 2)
send_sync(c);
/* Also send sync_req (could use NoOp) at 32-bit wrap to avoid having
* applications see sequence 0 as that is used to indicate
* an error in sending the request */
if((unsigned int) (c->out.request + 1) == 0)
send_sync(c);
/* The above send_sync calls could drop the I/O lock, but this
* thread will still exclude any other thread that tries to write,
* so the sequence number postconditions still hold. */
send_request(c, req->isvoid, workaround, flags, vector, veclen);
request = c->has_error ? 0 : c->out.request;
pthread_mutex_unlock(&c->iolock);
return request;
}